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dias
May 19, 2015 at 16:20
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Magnetized relativistic plasma as a Weyl metal by Volodya Miransky (Western University)
**
MASS 2015 Talks Tuesday May 19, 2015 I discuss several quantities that are central to our understanding of strong interaction dynamics and the exploration of the limits of the Standard Model, using numerical simulation of QCD on a space-time lattice. To this end I focus on the determination of structural properties of the nucleon, which has received special attention recently because of the proton radius puzzle. Secondly, I will discuss attempts to compute the hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon. [/flvcp3] [/flvcp3] Rare flavour-changing decays provide can probe well beyond the energy frontier and provide one of the most promising windows into TeV scale dynamics and beyond. I review key observables and recent theoretical and experimental results, and briefly comment on prospects for the near to medium term future. [/flvcp3] I will start by recalling the basic small- and large-field variants of inflation, emphasizing their UV sensitivity and the need for a UV completion, for example by string theory. Motivated by experimental searches for gravity waves or tensor modes, I will then focus on large-field models. In particular, I will discuss general no-go arguments against this version of inflation which are based on gravitational instantons and the so-called weak-gravity conjecture. Then I will turn to possible loopholes in those arguments and explain how certain string-theoretic constructions might, nevertheless, be able to realize large-field inflation. Some basic features of string compactifications and the string theory landscape will also be discussed. [/flvcp3] It has become recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena and heavy ion collisions. [/flvcp3]
dias
May 19, 2015 at 15:10
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Large-Field Inflation and String Theory by Arthur Hebecker (Heidelberg)
**
MASS 2015 Talks Tuesday May 19, 2015 I discuss several quantities that are central to our understanding of strong interaction dynamics and the exploration of the limits of the Standard Model, using numerical simulation of QCD on a space-time lattice. To this end I focus on the determination of structural properties of the nucleon, which has received special attention recently because of the proton radius puzzle. Secondly, I will discuss attempts to compute the hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon. [/flvcp3] [/flvcp3] Rare flavour-changing decays provide can probe well beyond the energy frontier and provide one of the most promising windows into TeV scale dynamics and beyond. I review key observables and recent theoretical and experimental results, and briefly comment on prospects for the near to medium term future. [/flvcp3] I will start by recalling the basic small- and large-field variants of inflation, emphasizing their UV sensitivity and the need for a UV completion, for example by string theory. Motivated by experimental searches for gravity waves or tensor modes, I will then focus on large-field models. In particular, I will discuss general no-go arguments against this version of inflation which are based on gravitational instantons and the so-called weak-gravity conjecture. Then I will turn to possible loopholes in those arguments and explain how certain string-theoretic constructions might, nevertheless, be able to realize large-field inflation. Some basic features of string compactifications and the string theory landscape will also be discussed. [/flvcp3] It has become recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena and heavy ion collisions. [/flvcp3]
dias
May 19, 2015 at 13:30
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Recent developments in flavour physics by Sebastian Jäger (University of Sussex)
**
MASS 2015 Talks Tuesday May 19, 2015 I discuss several quantities that are central to our understanding of strong interaction dynamics and the exploration of the limits of the Standard Model, using numerical simulation of QCD on a space-time lattice. To this end I focus on the determination of structural properties of the nucleon, which has received special attention recently because of the proton radius puzzle. Secondly, I will discuss attempts to compute the hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon. [/flvcp3] [/flvcp3] Rare flavour-changing decays provide can probe well beyond the energy frontier and provide one of the most promising windows into TeV scale dynamics and beyond. I review key observables and recent theoretical and experimental results, and briefly comment on prospects for the near to medium term future. [/flvcp3] I will start by recalling the basic small- and large-field variants of inflation, emphasizing their UV sensitivity and the need for a UV completion, for example by string theory. Motivated by experimental searches for gravity waves or tensor modes, I will then focus on large-field models. In particular, I will discuss general no-go arguments against this version of inflation which are based on gravitational instantons and the so-called weak-gravity conjecture. Then I will turn to possible loopholes in those arguments and explain how certain string-theoretic constructions might, nevertheless, be able to realize large-field inflation. Some basic features of string compactifications and the string theory landscape will also be discussed. [/flvcp3] It has become recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena and heavy ion collisions. [/flvcp3]
dias
May 19, 2015 at 10:40
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Hadrons in Vacuum and in Medium in an Effective Chiral Approach by Dirk Rischke (Frankfurt)
**
MASS 2015 Talks Tuesday May 19, 2015 I discuss several quantities that are central to our understanding of strong interaction dynamics and the exploration of the limits of the Standard Model, using numerical simulation of QCD on a space-time lattice. To this end I focus on the determination of structural properties of the nucleon, which has received special attention recently because of the proton radius puzzle. Secondly, I will discuss attempts to compute the hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon. [/flvcp3] [/flvcp3] Rare flavour-changing decays provide can probe well beyond the energy frontier and provide one of the most promising windows into TeV scale dynamics and beyond. I review key observables and recent theoretical and experimental results, and briefly comment on prospects for the near to medium term future. [/flvcp3] I will start by recalling the basic small- and large-field variants of inflation, emphasizing their UV sensitivity and the need for a UV completion, for example by string theory. Motivated by experimental searches for gravity waves or tensor modes, I will then focus on large-field models. In particular, I will discuss general no-go arguments against this version of inflation which are based on gravitational instantons and the so-called weak-gravity conjecture. Then I will turn to possible loopholes in those arguments and explain how certain string-theoretic constructions might, nevertheless, be able to realize large-field inflation. Some basic features of string compactifications and the string theory landscape will also be discussed. [/flvcp3] It has become recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena and heavy ion collisions. [/flvcp3]
dias
May 19, 2015 at 9:00
**
Low-energy Precision Observables and the Role of Lattice QCD by Hartmut Wittig (Mainz)
**
MASS 2015 Talks Tuesday May 19, 2015 I discuss several quantities that are central to our understanding of strong interaction dynamics and the exploration of the limits of the Standard Model, using numerical simulation of QCD on a space-time lattice. To this end I focus on the determination of structural properties of the nucleon, which has received special attention recently because of the proton radius puzzle. Secondly, I will discuss attempts to compute the hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon. [/flvcp3] [/flvcp3] Rare flavour-changing decays provide can probe well beyond the energy frontier and provide one of the most promising windows into TeV scale dynamics and beyond. I review key observables and recent theoretical and experimental results, and briefly comment on prospects for the near to medium term future. [/flvcp3] I will start by recalling the basic small- and large-field variants of inflation, emphasizing their UV sensitivity and the need for a UV completion, for example by string theory. Motivated by experimental searches for gravity waves or tensor modes, I will then focus on large-field models. In particular, I will discuss general no-go arguments against this version of inflation which are based on gravitational instantons and the so-called weak-gravity conjecture. Then I will turn to possible loopholes in those arguments and explain how certain string-theoretic constructions might, nevertheless, be able to realize large-field inflation. Some basic features of string compactifications and the string theory landscape will also be discussed. [/flvcp3] It has become recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena and heavy ion collisions. [/flvcp3]
dias
May 4, 2015
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Quarkonium with Effective field theories by Nora Brambrilla (Technische Universitaet Muenchen)
**
Quantum Chromodynamics (QCD) is the sector of the Standard Model of particle physics that describes the strong interaction, deceptively simple to formulate but notoriously difficult to solve. Heavy quarkonium is a multiscale system that probes the different energy regimes of QCD, from the high-energy region, where an expansion in the coupling constant is possible and precision studies may be done, to the low-energy region, dominated by confinement and the many manifestations of the nonperturbative strong dynamics. Properties of production and absorption of quarkonium in a medium are also crucial for the study of QCD at high density and temperature. On the theoretical side, the construction of new nonrelativistic effective field theories for quarkonium has recently revolutionized the field providing both a conceptual framework and a powerful calculational tool. On the experimental side, the diversity, quantity and accuracy of the data collected in the last few years at Belle, BESIII and at LHC experiments is impressive, featuring the observation of new states and new unexpected processes. I will discuss these theoretical and experimental advancements and their implications for our understanding of strong interactions.
dias
March 9, 2015
**
CP Violation in the Leptonic Sector by Gustavo Castelo-Branco (Lisbon, IST)
**
We review CP violation in the Standard Model, with emphasis on the leptonic sector. A method to study CP violation is described, including the derivation of weak-basis invariants relevant to both Dirac-type and Majorana-type CP violation. Furthermore, we propose that the observed large leptonic mixing may just reflect a quasi-degeneracy of three Majorana neutrinos. The limit of exact degeneracy of Majorana neutrinos is not trivial, as leptonic mixing and even CP violation may occur. We conjecture that the smallness of |U13|, when compared to the other elements of UPMNS, may be related to the fact that, in the limit of exact mass degeneracy, the leptonic mixing matrix necessarily has a vanishing element. We show that the lifting of the mass degeneracy can lead to the measured value of |U13| while at the same time accommodating the observed solar and atmospheric mixing angles.
dias
May 22, 2014 at 16:30
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Dynamical mass generation by gauge flavor dynamics by Jiří Hošek (NPI)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 22, 2014 at 15:40
**
Dark matter searches and astrophysical neutrinos in IceCube by Jason Koskinen (NBI)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 22, 2014 at 14:20
**
Theta dependence of 4D SU(N) gauge theories by Ettore Vicari (Pisa)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 22, 2014 at 13:30
**
Constraints on matter from asymptotic safety by Roberto Percacci (SISSA)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 22, 2014 at 11:10
**
Chiral symmetry and Quarkyonic vs. Superfluid/Color-Supercondor phases in SU(N) gauge theories at high density by Terry Tomboulis (UCLA)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 22, 2014 at 10:20
**
On massive gauge theories beyond perturbation theory by Pilar Hernández Gamazo (Valencia)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 22, 2014 at 9:00
**
Exploring the Universe at the highest energies with the Pierre Auger Observatory by Karl-Heinz Kampert (Wuppertal)
**
MASS 2014 Talks Thursday May 22, 2014 Much progress has been made in observations of the most energetic particles in Nature but major puzzles remain to be solved. In particular, a flux suppression of cosmic rays has been observed above 5x10^19 eV, such as expected from photo-pion production by protons propagating through the CMB (GZK-effect). However, data from the Pierre Auger Observatory, the worlds largest cosmic ray observatory located in Argentina, show a shift towards heavier primary particles above 5x10^18 eV and suggest seeing the maximum energy of cosmic particle accelerators rather than energy losses by propagation effects. We shall review the experimental data and discuss its consequences. Observing particles up to 10^20 eV enable tests also of particle and of fundamental physics, such as features of hadronic interaction at energies up to sqrt(s)=100 TeV, as well as tests Lorentz invariance and smoothness of space-time structure. We shall end the presentation by outlining plans for the near-term future and discussing the prospects and future challenges of UHECR physics. [/flvcp3] We discuss the simplest non-perturbative formulation of a massive SU(2) gauge theory on the lattice, which is equivalent to a non-linear chiral model. We search for lines of constant physics and find a scaling region where both a triplet vector and singlet scalar remain light. We discuss the structure of the effective theory describing the dynamics of these light degrees of freedom. [/flvcp3] The regime of (asymptotically) high quark chemical potential $\mu$ is of great physical interest; arguments over many years have suggested the possibility of superfluidity or color superconductivity phases in this region of the phase diagram. This large $\mu$ regime, however, has been largely inaccessible to direct numerical simulation due to the complex fermion determinant problem. Even in the case of theories with real determinant, such as two-color QCD, MC simulations with light fermions appear at least an order of magnitude more challenging than at zero density. In recent years concrete results have been obtained on the lattice starting from the strong coupling end by a combination of simulations in special partition function representations, sophisticated mean field analysis, and simulations in two-color QCD. Recently, cluster expansions shown to converge at large $\mu$ have produce definitive results at strong coupling. After reviewing these results we will show how the cluster expansion method can be extended to all gauge couplings in the case of theories with real determinant and discuss the resulting physical picture. [/flvcp3] The existence of a nontrivial fixed point with finitely many relevant directions is a sufficient condition for an UV complete and predictive QFT. There is evidence for the existence of such a fixed point for pure gravity. I will discuss constraints on the number of scalar, fermion and vector fields minimally coupled to gravity, arising from the existence of the fixed point. [/flvcp3] The dependence of 4D SU(N) gauge theories on the topological theta term is discussed at zero and finite temperature, in particular in the large-N limit. General arguments and numerical analyses (exploiting the lattice formulation) show that the theta dependence drastically changes across the deconfinement transition. The low-T phase is characterized by a large-N scaling with theta/N as relevant variable, while in the high-T phase the scaling variable is just theta and the free energy is essentially determined by the instanton-gas approximation. [/flvcp3] Abstract: The IceCube neutrino observatory at the South Pole includes a cubic kilometer of instrumented ice which serves as a unique telescope for exploring the cosmos. The physics portfolio of the project covers searches for neutrino emission from the annihilation of dark matter and the observation of astrophysical neutrinos and searches for their possible sources. I will cover the most recent dark matter results in addition to the IceCube astrophysical neutrino results. I will conclude with prospects for next generation detector upgrades that will improve sensitivity at the both the O(1) GeV and > O(100) TeV energies. [/flvcp3] See arXiv:1401.7503. [/flvcp3]
dias
May 21, 2014 at 16:30
**
Scale invariant extensions of the SM with strongly interacting hidden sector by Pyungwon Ko (KIAS)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 21, 2014 at 15:40
**
Progress towards an a-theorem by Ian Jack (Liverpool)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 21, 2014 at 14:20
**
Exact Scale Breaking and Novel Higgs Potentials by Steven Abel (Durham IPPP)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 21, 2014 at 13:30
**
Axion-like Particles from Strings by Andreas Ringwald (DESY)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 21, 2014 at 11:10
**
Conformal Electroweak Symmetry Breaking and implications for neutrinos and dark matter by Manfred Lindner (MPI, Heidelberg)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 21, 2014 at 10:20
**
WISPy Cold Dark Matter by Joerg Jaeckel (Heidelberg)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 21, 2014 at 9:00
**
Shedding light on (WIMP) dark matter with LUX by Henrique Araujo (Imperial College London)
**
MASS 2014 Talks Wednesday May 21, 2014 The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA. Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIMPs relative to the previous leading experiment, changing the landscape of direct searches for light WIMPs. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014. [/flvcp3] Very light bosons, produced non-thermally in the early Universe are an intriguing possibility for the cold dark matter of the Universe. Particularly interesting candidates are axions, axion-like particles and hidden photons. This talk will discuss the current status of such light dark matter with a particular emphasis towards opportunities for its detection. [/flvcp3] New ideas about the role of conformal symmetry for electro-weak symmetry breaking will be discussed in general and some models will be described in detail. Some interesting implications for neutrino physics and dark matter will also be discussed. [/flvcp3] There are various puzzling astrophysical and cosmological phenomena which may be explained by the existence of light axion-like particles (ALPs) with a tiny coupling to two photons. For example, the anomalous transparency of the universe for gamma rays may be explained by oscillations of photons into sub-microeV mass ALPs (and vice versa) in ambient magnetic fields and a recently found unidentified X-ray line may arise from the two photon decay of a keV mass ALP comprising a part or even the total of dark matter. In this talk, we will discuss how such ALPs may arise naturally from strings. [/flvcp3] We present a gauge mediation principle for theories where exact UV scale invariance is broken in a hidden sector. The relevant configurations are those in which the visible sector and a hidden sector emanate from a scale invariant pair of UV theories that communicate only via gauge interactions. We compute the relevant operators of the Higgs sector (which arise at two and three loops). The potential contains logarithmic mass-squared terms which lead to three different low energy configurations. In the first the Higgs sector is the same as that of the usual Standard Model, with the negative Higgs mass-squared arising naturally from radiative corrections. The second has dominant logarithmic mass-squared terms for the Higgs, allowing the electroweak symmetry breaking minimum to be at zero vacuum energy or metastable. In the third configuration the effective potential has negligible quartic term, and yet electroweak symmetry is broken radiatively by a "running-Higgs-mass-squared". The phenomenology of the two new configurations is identical to that of the Standard Model, except for the Higgs self-couplings which are substantially different. [/flvcp3] We discuss recent progress towards an a-theorem governing renormalisation-group flow in four-dimensional quantum field theories, focussing on explicit perturbative results. We also discuss the evidence for an explicit all-orders a-function in supersymmetric theories. [/flvcp3] [/flvcp3]
dias
May 20, 2014 at 11:10
**
Compositeness and Lattice Strong Dynamics by Pavlos M. Vranas (LLNL)
**
MASS 2014 Talks Tuesday May 20, 2014 Neutrinos may be Majorana particles. If so, neutrino less double beta decay processes could be observed by the next generation of bb0nu experiments. I will briefly review the state of the art, then discuss one of the most promising ideas in the field, the use of Hight Pressure Gas Xenon TPC (HPGXe) with electroluminescence gain and optical readout. A 100 kg incarnation of such a device will start operations at the Canfranc Underground Lab in Spain in 2015. The technology can be extrapolated to 1 ton, and thus lead the exploration of the inverse hierarchy in Majorana landscape. [/flvcp3] With the discovery of a Higgs-like particle at the LHC we are leaving through a unique time in which unprecedented experimental means and expertise are matched by the results of decades of theoretical efforts to provide the most accurate description of collider data. The evidence for this new particle has given us some crucial hints to understand the nature of the electroweak interactions, and the accurate determination of its properties could provide further indirect evidence of new physics. In this talk I will review some of the theoretical developments that have played a crucial role in the discovery of a Higgs boson and will be essential in measuring its properties. [/flvcp3] Dark matter may be composite, made up of electroweak charged constituents, bound by a new strong force so that the composite particle is neutral and has diminishingly small interactions with ordinary matter. In addition, the breaking of electroweak symmetry and the emergence of the Higgs particle may be the result of spontaneous chiral symmetry breaking of a new underlying strongly interacting theory. These can be gauge theories with certain number of colors, flavors and fermion representations. In that case, their strong dynamics can be studied using Lattice Gauge Theory methods very much like Lattice QCD. Here I will present lattice simulation results from the Lattice Strong Dynamics (LSD) collaboration on possible composite dark matter models and the associated experimental exclusions, as well as results on conformality and compositeness for strongly interacting theories of electroweak symmetry breaking. [/flvcp3]
dias
May 20, 2014 at 10:20
**
Higgs-boson phenomenology: from discovery to precision physics by Laura Reina (Florida)
**
MASS 2014 Talks Tuesday May 20, 2014 Neutrinos may be Majorana particles. If so, neutrino less double beta decay processes could be observed by the next generation of bb0nu experiments. I will briefly review the state of the art, then discuss one of the most promising ideas in the field, the use of Hight Pressure Gas Xenon TPC (HPGXe) with electroluminescence gain and optical readout. A 100 kg incarnation of such a device will start operations at the Canfranc Underground Lab in Spain in 2015. The technology can be extrapolated to 1 ton, and thus lead the exploration of the inverse hierarchy in Majorana landscape. [/flvcp3] With the discovery of a Higgs-like particle at the LHC we are leaving through a unique time in which unprecedented experimental means and expertise are matched by the results of decades of theoretical efforts to provide the most accurate description of collider data. The evidence for this new particle has given us some crucial hints to understand the nature of the electroweak interactions, and the accurate determination of its properties could provide further indirect evidence of new physics. In this talk I will review some of the theoretical developments that have played a crucial role in the discovery of a Higgs boson and will be essential in measuring its properties. [/flvcp3] Dark matter may be composite, made up of electroweak charged constituents, bound by a new strong force so that the composite particle is neutral and has diminishingly small interactions with ordinary matter. In addition, the breaking of electroweak symmetry and the emergence of the Higgs particle may be the result of spontaneous chiral symmetry breaking of a new underlying strongly interacting theory. These can be gauge theories with certain number of colors, flavors and fermion representations. In that case, their strong dynamics can be studied using Lattice Gauge Theory methods very much like Lattice QCD. Here I will present lattice simulation results from the Lattice Strong Dynamics (LSD) collaboration on possible composite dark matter models and the associated experimental exclusions, as well as results on conformality and compositeness for strongly interacting theories of electroweak symmetry breaking. [/flvcp3]
dias
May 20, 2014 at 9:00
**
The @next neutrinoless double beta decay experiment by Juan José Gómez-Cadenas (IFIC (CSIC & UVEG))
**
MASS 2014 Talks Tuesday May 20, 2014 Neutrinos may be Majorana particles. If so, neutrino less double beta decay processes could be observed by the next generation of bb0nu experiments. I will briefly review the state of the art, then discuss one of the most promising ideas in the field, the use of Hight Pressure Gas Xenon TPC (HPGXe) with electroluminescence gain and optical readout. A 100 kg incarnation of such a device will start operations at the Canfranc Underground Lab in Spain in 2015. The technology can be extrapolated to 1 ton, and thus lead the exploration of the inverse hierarchy in Majorana landscape. [/flvcp3] With the discovery of a Higgs-like particle at the LHC we are leaving through a unique time in which unprecedented experimental means and expertise are matched by the results of decades of theoretical efforts to provide the most accurate description of collider data. The evidence for this new particle has given us some crucial hints to understand the nature of the electroweak interactions, and the accurate determination of its properties could provide further indirect evidence of new physics. In this talk I will review some of the theoretical developments that have played a crucial role in the discovery of a Higgs boson and will be essential in measuring its properties. [/flvcp3] Dark matter may be composite, made up of electroweak charged constituents, bound by a new strong force so that the composite particle is neutral and has diminishingly small interactions with ordinary matter. In addition, the breaking of electroweak symmetry and the emergence of the Higgs particle may be the result of spontaneous chiral symmetry breaking of a new underlying strongly interacting theory. These can be gauge theories with certain number of colors, flavors and fermion representations. In that case, their strong dynamics can be studied using Lattice Gauge Theory methods very much like Lattice QCD. Here I will present lattice simulation results from the Lattice Strong Dynamics (LSD) collaboration on possible composite dark matter models and the associated experimental exclusions, as well as results on conformality and compositeness for strongly interacting theories of electroweak symmetry breaking. [/flvcp3]
dias
May 19, 2014 at 16:30
**
Lattice Radial Quantization by George T. Fleming (Yale University)
**
MASS 2014 Talks Monday May 19, 2014 Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and are subject of increasing interest by experimentalists. I will present the different experimental strategies to detect these particles, and I will briefly review their current status and future prospects. Then I will focus on the International Axion Observatory (IAXO), the most ambitious project currently under consideration. IAXO will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or ALPs originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to- date. IAXO has also potential to host additional detection setups. Most interestingly, the large magnetic volume of IAXO could be used to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. [/flvcp3] While elementary particles get their mass from a Higgs-like mechanism, the origin of the mass of ordinary matter is non-perturbative, strong interaction dynamics. This has been unambiguously confirmed in the last few years, thanks to the tremendous progress undergone by ab-initio calculations in lattice quantum chromodynamics (QCD). After reviewing this progress, I will show how lattice QCD is allowing us to investigate many different aspects of mass. These applications range from providing the theory required to "measure" quark masses, to explaining important aspects of the stability of ordinary matter, through determining the coupling of possible WIMP dark matter, which could constitute 85% of the total matter in the universe, to the ordinary matter of WIMP detectors. [/flvcp3] The insular nature of the Standard Model may be explained if the Higgs potential is only sensitive to quantum corrections from masses associated with physical states. Starting from a scale-free electroweak sector, we show that heavy right-handed neutrinos can be the origin of mass for scalar dark matter, in a framework with two scalar doublets. In turn, below the mass of heavy neutrinos, the dark matter sector sets the scale of electroweak symmetry breaking. The successive transmission of mass scale from right-handed neutrinos occurs at the quantum level. This framework includes all the necessary ingredients to provide a viable dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. [/flvcp3] Do interacting UV fixed points exist, and if so, what can we do with them? The talk by Daniel Litim (Sussex) will be available later. I will discuss how imposing the successful leptogenesis bound one obtains interesting constraints on those high energy parameters characterising right-handed (RH) neutrino parameters in the see-saw mechanism. This provides a useful guidance among the many existing models especially when a condition of independence of the initial conditions is further added (strong thermal leptogenesis condition). In this case a particular (hierarchical) RH neutrino mass spectrum is singled out that, interestingly, is realised in SO(10)-inspired models. I will also discuss how the strong thermal leptogenesis condition by itself (i.e. model independently) favours values of the absolute neutrino mass scale that imply deviations from the hierarchical limit that might be experimentally detected in absolute neutrino mass scale experiments, especially in the case of normally ordered light neutrinos. In this way, leptogenesis acts as an important tool to connect low energy neutrino data to models. [/flvcp3] QCD with a relatively large number of fundamentally charged quark flavours in the chiral limit is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Hereby, the critical number of quark flavours depends crucially on the non-perturbative tensor structures of the quark-gluon vertex. [/flvcp3] I present the current status of a program to formulate D-dimensional strongly-coupled relativistic quantum field theories on lattice discretizations of cylindrical manifolds whose cross-section is a (D-1)-dimensional sphere. Critical points in such theories should correspond to Conformal Field Theories (CFTs) if the full rotational symmetry of the sphere can be recovered in the continuum limit. If the formulation is successful, studying these CFTs should be numerically much less expensive that the equivalent calculations on a D-dimensional torus. [/flvcp3] Conformal bootstrap in 4D The talk by Oleg Antipin (INFN) will be available later.
dias
May 19, 2014 at 15:40
**
Non-perturbative propagators and running coupling in the conformal window of QCD by Reinhard Alkofer (Graz)
**
MASS 2014 Talks Monday May 19, 2014 Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and are subject of increasing interest by experimentalists. I will present the different experimental strategies to detect these particles, and I will briefly review their current status and future prospects. Then I will focus on the International Axion Observatory (IAXO), the most ambitious project currently under consideration. IAXO will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or ALPs originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to- date. IAXO has also potential to host additional detection setups. Most interestingly, the large magnetic volume of IAXO could be used to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. [/flvcp3] While elementary particles get their mass from a Higgs-like mechanism, the origin of the mass of ordinary matter is non-perturbative, strong interaction dynamics. This has been unambiguously confirmed in the last few years, thanks to the tremendous progress undergone by ab-initio calculations in lattice quantum chromodynamics (QCD). After reviewing this progress, I will show how lattice QCD is allowing us to investigate many different aspects of mass. These applications range from providing the theory required to "measure" quark masses, to explaining important aspects of the stability of ordinary matter, through determining the coupling of possible WIMP dark matter, which could constitute 85% of the total matter in the universe, to the ordinary matter of WIMP detectors. [/flvcp3] The insular nature of the Standard Model may be explained if the Higgs potential is only sensitive to quantum corrections from masses associated with physical states. Starting from a scale-free electroweak sector, we show that heavy right-handed neutrinos can be the origin of mass for scalar dark matter, in a framework with two scalar doublets. In turn, below the mass of heavy neutrinos, the dark matter sector sets the scale of electroweak symmetry breaking. The successive transmission of mass scale from right-handed neutrinos occurs at the quantum level. This framework includes all the necessary ingredients to provide a viable dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. [/flvcp3] Do interacting UV fixed points exist, and if so, what can we do with them? The talk by Daniel Litim (Sussex) will be available later. I will discuss how imposing the successful leptogenesis bound one obtains interesting constraints on those high energy parameters characterising right-handed (RH) neutrino parameters in the see-saw mechanism. This provides a useful guidance among the many existing models especially when a condition of independence of the initial conditions is further added (strong thermal leptogenesis condition). In this case a particular (hierarchical) RH neutrino mass spectrum is singled out that, interestingly, is realised in SO(10)-inspired models. I will also discuss how the strong thermal leptogenesis condition by itself (i.e. model independently) favours values of the absolute neutrino mass scale that imply deviations from the hierarchical limit that might be experimentally detected in absolute neutrino mass scale experiments, especially in the case of normally ordered light neutrinos. In this way, leptogenesis acts as an important tool to connect low energy neutrino data to models. [/flvcp3] QCD with a relatively large number of fundamentally charged quark flavours in the chiral limit is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Hereby, the critical number of quark flavours depends crucially on the non-perturbative tensor structures of the quark-gluon vertex. [/flvcp3] I present the current status of a program to formulate D-dimensional strongly-coupled relativistic quantum field theories on lattice discretizations of cylindrical manifolds whose cross-section is a (D-1)-dimensional sphere. Critical points in such theories should correspond to Conformal Field Theories (CFTs) if the full rotational symmetry of the sphere can be recovered in the continuum limit. If the formulation is successful, studying these CFTs should be numerically much less expensive that the equivalent calculations on a D-dimensional torus. [/flvcp3] Conformal bootstrap in 4D The talk by Oleg Antipin (INFN) will be available later.
dias
May 19, 2014 at 14:20
**
From lowe energy neutrino data to mass models (and back) with leptogenesis. by Pasquale Di Bari (Southampton)
**
MASS 2014 Talks Monday May 19, 2014 Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and are subject of increasing interest by experimentalists. I will present the different experimental strategies to detect these particles, and I will briefly review their current status and future prospects. Then I will focus on the International Axion Observatory (IAXO), the most ambitious project currently under consideration. IAXO will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or ALPs originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to- date. IAXO has also potential to host additional detection setups. Most interestingly, the large magnetic volume of IAXO could be used to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. [/flvcp3] While elementary particles get their mass from a Higgs-like mechanism, the origin of the mass of ordinary matter is non-perturbative, strong interaction dynamics. This has been unambiguously confirmed in the last few years, thanks to the tremendous progress undergone by ab-initio calculations in lattice quantum chromodynamics (QCD). After reviewing this progress, I will show how lattice QCD is allowing us to investigate many different aspects of mass. These applications range from providing the theory required to "measure" quark masses, to explaining important aspects of the stability of ordinary matter, through determining the coupling of possible WIMP dark matter, which could constitute 85% of the total matter in the universe, to the ordinary matter of WIMP detectors. [/flvcp3] The insular nature of the Standard Model may be explained if the Higgs potential is only sensitive to quantum corrections from masses associated with physical states. Starting from a scale-free electroweak sector, we show that heavy right-handed neutrinos can be the origin of mass for scalar dark matter, in a framework with two scalar doublets. In turn, below the mass of heavy neutrinos, the dark matter sector sets the scale of electroweak symmetry breaking. The successive transmission of mass scale from right-handed neutrinos occurs at the quantum level. This framework includes all the necessary ingredients to provide a viable dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. [/flvcp3] Do interacting UV fixed points exist, and if so, what can we do with them? The talk by Daniel Litim (Sussex) will be available later. I will discuss how imposing the successful leptogenesis bound one obtains interesting constraints on those high energy parameters characterising right-handed (RH) neutrino parameters in the see-saw mechanism. This provides a useful guidance among the many existing models especially when a condition of independence of the initial conditions is further added (strong thermal leptogenesis condition). In this case a particular (hierarchical) RH neutrino mass spectrum is singled out that, interestingly, is realised in SO(10)-inspired models. I will also discuss how the strong thermal leptogenesis condition by itself (i.e. model independently) favours values of the absolute neutrino mass scale that imply deviations from the hierarchical limit that might be experimentally detected in absolute neutrino mass scale experiments, especially in the case of normally ordered light neutrinos. In this way, leptogenesis acts as an important tool to connect low energy neutrino data to models. [/flvcp3] QCD with a relatively large number of fundamentally charged quark flavours in the chiral limit is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Hereby, the critical number of quark flavours depends crucially on the non-perturbative tensor structures of the quark-gluon vertex. [/flvcp3] I present the current status of a program to formulate D-dimensional strongly-coupled relativistic quantum field theories on lattice discretizations of cylindrical manifolds whose cross-section is a (D-1)-dimensional sphere. Critical points in such theories should correspond to Conformal Field Theories (CFTs) if the full rotational symmetry of the sphere can be recovered in the continuum limit. If the formulation is successful, studying these CFTs should be numerically much less expensive that the equivalent calculations on a D-dimensional torus. [/flvcp3] Conformal bootstrap in 4D The talk by Oleg Antipin (INFN) will be available later.
dias
May 19, 2014 at 11:10
**
Right-Handed Neutrinos as the Origin of the Electroweak Scale by Hooman Davoudiasl (BNL)
**
MASS 2014 Talks Monday May 19, 2014 Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and are subject of increasing interest by experimentalists. I will present the different experimental strategies to detect these particles, and I will briefly review their current status and future prospects. Then I will focus on the International Axion Observatory (IAXO), the most ambitious project currently under consideration. IAXO will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or ALPs originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to- date. IAXO has also potential to host additional detection setups. Most interestingly, the large magnetic volume of IAXO could be used to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. [/flvcp3] While elementary particles get their mass from a Higgs-like mechanism, the origin of the mass of ordinary matter is non-perturbative, strong interaction dynamics. This has been unambiguously confirmed in the last few years, thanks to the tremendous progress undergone by ab-initio calculations in lattice quantum chromodynamics (QCD). After reviewing this progress, I will show how lattice QCD is allowing us to investigate many different aspects of mass. These applications range from providing the theory required to "measure" quark masses, to explaining important aspects of the stability of ordinary matter, through determining the coupling of possible WIMP dark matter, which could constitute 85% of the total matter in the universe, to the ordinary matter of WIMP detectors. [/flvcp3] The insular nature of the Standard Model may be explained if the Higgs potential is only sensitive to quantum corrections from masses associated with physical states. Starting from a scale-free electroweak sector, we show that heavy right-handed neutrinos can be the origin of mass for scalar dark matter, in a framework with two scalar doublets. In turn, below the mass of heavy neutrinos, the dark matter sector sets the scale of electroweak symmetry breaking. The successive transmission of mass scale from right-handed neutrinos occurs at the quantum level. This framework includes all the necessary ingredients to provide a viable dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. [/flvcp3] Do interacting UV fixed points exist, and if so, what can we do with them? The talk by Daniel Litim (Sussex) will be available later. I will discuss how imposing the successful leptogenesis bound one obtains interesting constraints on those high energy parameters characterising right-handed (RH) neutrino parameters in the see-saw mechanism. This provides a useful guidance among the many existing models especially when a condition of independence of the initial conditions is further added (strong thermal leptogenesis condition). In this case a particular (hierarchical) RH neutrino mass spectrum is singled out that, interestingly, is realised in SO(10)-inspired models. I will also discuss how the strong thermal leptogenesis condition by itself (i.e. model independently) favours values of the absolute neutrino mass scale that imply deviations from the hierarchical limit that might be experimentally detected in absolute neutrino mass scale experiments, especially in the case of normally ordered light neutrinos. In this way, leptogenesis acts as an important tool to connect low energy neutrino data to models. [/flvcp3] QCD with a relatively large number of fundamentally charged quark flavours in the chiral limit is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Hereby, the critical number of quark flavours depends crucially on the non-perturbative tensor structures of the quark-gluon vertex. [/flvcp3] I present the current status of a program to formulate D-dimensional strongly-coupled relativistic quantum field theories on lattice discretizations of cylindrical manifolds whose cross-section is a (D-1)-dimensional sphere. Critical points in such theories should correspond to Conformal Field Theories (CFTs) if the full rotational symmetry of the sphere can be recovered in the continuum limit. If the formulation is successful, studying these CFTs should be numerically much less expensive that the equivalent calculations on a D-dimensional torus. [/flvcp3] Conformal bootstrap in 4D The talk by Oleg Antipin (INFN) will be available later.
dias
May 19, 2014 at 10:20
**
Mass and Lattice QCD by Laurent Lellouch (CPT Marseille, CNRS & Aix-Marseille U)
**
MASS 2014 Talks Monday May 19, 2014 Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and are subject of increasing interest by experimentalists. I will present the different experimental strategies to detect these particles, and I will briefly review their current status and future prospects. Then I will focus on the International Axion Observatory (IAXO), the most ambitious project currently under consideration. IAXO will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or ALPs originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to- date. IAXO has also potential to host additional detection setups. Most interestingly, the large magnetic volume of IAXO could be used to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. [/flvcp3] While elementary particles get their mass from a Higgs-like mechanism, the origin of the mass of ordinary matter is non-perturbative, strong interaction dynamics. This has been unambiguously confirmed in the last few years, thanks to the tremendous progress undergone by ab-initio calculations in lattice quantum chromodynamics (QCD). After reviewing this progress, I will show how lattice QCD is allowing us to investigate many different aspects of mass. These applications range from providing the theory required to "measure" quark masses, to explaining important aspects of the stability of ordinary matter, through determining the coupling of possible WIMP dark matter, which could constitute 85% of the total matter in the universe, to the ordinary matter of WIMP detectors. [/flvcp3] The insular nature of the Standard Model may be explained if the Higgs potential is only sensitive to quantum corrections from masses associated with physical states. Starting from a scale-free electroweak sector, we show that heavy right-handed neutrinos can be the origin of mass for scalar dark matter, in a framework with two scalar doublets. In turn, below the mass of heavy neutrinos, the dark matter sector sets the scale of electroweak symmetry breaking. The successive transmission of mass scale from right-handed neutrinos occurs at the quantum level. This framework includes all the necessary ingredients to provide a viable dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. [/flvcp3] Do interacting UV fixed points exist, and if so, what can we do with them? The talk by Daniel Litim (Sussex) will be available later. I will discuss how imposing the successful leptogenesis bound one obtains interesting constraints on those high energy parameters characterising right-handed (RH) neutrino parameters in the see-saw mechanism. This provides a useful guidance among the many existing models especially when a condition of independence of the initial conditions is further added (strong thermal leptogenesis condition). In this case a particular (hierarchical) RH neutrino mass spectrum is singled out that, interestingly, is realised in SO(10)-inspired models. I will also discuss how the strong thermal leptogenesis condition by itself (i.e. model independently) favours values of the absolute neutrino mass scale that imply deviations from the hierarchical limit that might be experimentally detected in absolute neutrino mass scale experiments, especially in the case of normally ordered light neutrinos. In this way, leptogenesis acts as an important tool to connect low energy neutrino data to models. [/flvcp3] QCD with a relatively large number of fundamentally charged quark flavours in the chiral limit is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Hereby, the critical number of quark flavours depends crucially on the non-perturbative tensor structures of the quark-gluon vertex. [/flvcp3] I present the current status of a program to formulate D-dimensional strongly-coupled relativistic quantum field theories on lattice discretizations of cylindrical manifolds whose cross-section is a (D-1)-dimensional sphere. Critical points in such theories should correspond to Conformal Field Theories (CFTs) if the full rotational symmetry of the sphere can be recovered in the continuum limit. If the formulation is successful, studying these CFTs should be numerically much less expensive that the equivalent calculations on a D-dimensional torus. [/flvcp3] Conformal bootstrap in 4D The talk by Oleg Antipin (INFN) will be available later.
dias
May 19, 2014 at 9:00
**
Present and Future of axion searches: the International AXion Observatory IAXO by Igor G. Irastorza (Zaragoza)
**
MASS 2014 Talks Monday May 19, 2014 Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and are subject of increasing interest by experimentalists. I will present the different experimental strategies to detect these particles, and I will briefly review their current status and future prospects. Then I will focus on the International Axion Observatory (IAXO), the most ambitious project currently under consideration. IAXO will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or ALPs originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to- date. IAXO has also potential to host additional detection setups. Most interestingly, the large magnetic volume of IAXO could be used to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. [/flvcp3] While elementary particles get their mass from a Higgs-like mechanism, the origin of the mass of ordinary matter is non-perturbative, strong interaction dynamics. This has been unambiguously confirmed in the last few years, thanks to the tremendous progress undergone by ab-initio calculations in lattice quantum chromodynamics (QCD). After reviewing this progress, I will show how lattice QCD is allowing us to investigate many different aspects of mass. These applications range from providing the theory required to "measure" quark masses, to explaining important aspects of the stability of ordinary matter, through determining the coupling of possible WIMP dark matter, which could constitute 85% of the total matter in the universe, to the ordinary matter of WIMP detectors. [/flvcp3] The insular nature of the Standard Model may be explained if the Higgs potential is only sensitive to quantum corrections from masses associated with physical states. Starting from a scale-free electroweak sector, we show that heavy right-handed neutrinos can be the origin of mass for scalar dark matter, in a framework with two scalar doublets. In turn, below the mass of heavy neutrinos, the dark matter sector sets the scale of electroweak symmetry breaking. The successive transmission of mass scale from right-handed neutrinos occurs at the quantum level. This framework includes all the necessary ingredients to provide a viable dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. [/flvcp3] Do interacting UV fixed points exist, and if so, what can we do with them? The talk by Daniel Litim (Sussex) will be available later. I will discuss how imposing the successful leptogenesis bound one obtains interesting constraints on those high energy parameters characterising right-handed (RH) neutrino parameters in the see-saw mechanism. This provides a useful guidance among the many existing models especially when a condition of independence of the initial conditions is further added (strong thermal leptogenesis condition). In this case a particular (hierarchical) RH neutrino mass spectrum is singled out that, interestingly, is realised in SO(10)-inspired models. I will also discuss how the strong thermal leptogenesis condition by itself (i.e. model independently) favours values of the absolute neutrino mass scale that imply deviations from the hierarchical limit that might be experimentally detected in absolute neutrino mass scale experiments, especially in the case of normally ordered light neutrinos. In this way, leptogenesis acts as an important tool to connect low energy neutrino data to models. [/flvcp3] QCD with a relatively large number of fundamentally charged quark flavours in the chiral limit is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Hereby, the critical number of quark flavours depends crucially on the non-perturbative tensor structures of the quark-gluon vertex. [/flvcp3] I present the current status of a program to formulate D-dimensional strongly-coupled relativistic quantum field theories on lattice discretizations of cylindrical manifolds whose cross-section is a (D-1)-dimensional sphere. Critical points in such theories should correspond to Conformal Field Theories (CFTs) if the full rotational symmetry of the sphere can be recovered in the continuum limit. If the formulation is successful, studying these CFTs should be numerically much less expensive that the equivalent calculations on a D-dimensional torus. [/flvcp3] Conformal bootstrap in 4D The talk by Oleg Antipin (INFN) will be available later.
dias
December 16, 2013 at 16:00
**
An Introduction to the Brout-Englert-Higgs Mechanism by Diego Becciolini (CP3-Origins)
**
The discovery of a new particle with the right properties to be the so-called 'Higgs boson' at the LHC last year was a further confirmation that the Standard Model formulation, with the spontaneous breaking of the Electro-Weak symmetry, is indeed a good description of Nature. Consequently, this year's Nobel Prize in Physics was awarded to François Englert and Peter Higgs “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider”. In this lecture I will try to give an overview, at a very basic level, of the main technical ideas that underline the BEH mechanism: what mass means, what symmetry breaking means, what gauge symmetries are, and finally what happens when combining the latter two ingredients... It is a simple repetition of the lecture I gave in November to allow more people to attend. The talk is intended for our genius students, but everybody is welcome. Here are some problems for you to work on after the lecture.
dias
November 25, 2013
**
SUSY naturalness without prejudice by Dumitru Ghilencea (CERN & NIPNE Bucharest)
**
Unlike the Standard Model, supersymmetric models stabilize the EW scale v and predict that it is function of the SUSY UV parameters (p_i). I provide a comparative study of the EW fine tuning Delta (measuring this stability) in the most popular SUSY models consistent with recent LHC results for the Higgs sector. I show that if one insists on fixing the EW scale v=v(p_i) to its numerical value, the likelihood to fit the EW data is suppressed by Delta (under some assumptions). From this, the condition of a good fit provides an estimate of a model-independent bound for the EW scale fine-tuning: Delta<<exp(d.o.f./2), (d.o.f. = number of the degrees of freedom). Popular SUSY models: CMSSM, NUHM1, NUHM2, NMSSM, and MSSM with non-universal gaugino masses are examined, to see if this bound on Delta is respected. A more general approach shows that the covariance matrix of a model encodes all the information about the EW fine tuning provided that v=v(p_i) and is therefore more fundamental than Delta. The latter may thus be less relevant for the viability of a model, as long as with v=v(p_i) a good fit of the data is still possible.
dias
October 14, 2013
**
The Scale of Dark QCD by Pedro Schwaller (CERN)
**
Most of the mass of ordinary matter has its origin from quantum chromodynamics (QCD). A similar strong dynamics, dark QCD, could exist to explain the mass origin of dark matter. Using infrared fixed points of the two gauge couplings, we provide a dynamical mechanism that relates the dark QCD confinement scale to our QCD scale, and hence provides an explanation for comparable dark baryon and proton masses. Together with a mechanism that generates equal amounts of dark baryon and ordinary baryon asymmetries in the early universe, the similarity of dark matter and ordinary matter energy densities is naturally explained. For a large class of gauge group representations, the particles charged under both QCD and dark QCD, necessary ingredients for generating the infrared fixed points, are found to have TeV scale masses, which sets the scale for dark matter direct detection and novel collider signatures involving visible and dark jets. Based on arxiv:1306:4676 with Y. Bai.
dias
September 30, 2013
**
Inflation on Random Landscapes by Thorsten Battefeld (University of Göttingen, Germany)
**
Moduli spaces in string theory, often dubbed Landscapes, are usually of high dimensionality and feature a complicated potential. Is multi-field inflation on such landscapes consistent with current observations by PLANCK? Modeling such landscapes by random potentials offers the opportunity to asses generic features of inflation. Random matrix theory provides a tool (complementing numerical experiments) to address many questions analytically, without requiring a detailed knowledge of the potential, i.e. details of the compactification, due to the feature of universality. Thus, the generic prediction of a landscape in string theory can be put to the test. I will discuss the preference of saddle point inflation in a class of landscapes, commenting on the role of eternal inflation, anthropic arguments and the measure problem within this framework. As an application, I will discuss how current constraints on non-Gaussianities impose bounds on the curvature of the end-of-inflation hyper-surface in this class of models, which in turn imposes constraints on the topography of the landscape.
dias
June 24, 2013
**
Flavor violating Higgs decays by Joachim Kopp (Max Planck Institut fur Kernphysik (MPI))
**
The discovery of a Higgs-like boson by ATLAS and CMS has opened up a new window to physics beyond the Standard Model. A particularly interesting class of new observables are flavour violating couplings of the Higgs boson to quarks or leptons, which are generically expected in many extensions of the Standard Model, for instance in multi-Higgs doublet models, extra-dimensional scenarios, and models of compositeness. In this talk, we present a comprehensive set of constraints on flavour violating Higgs couplings using data on rare decays, meson oscillations, dipole moments and other precision observables. While these low-energy constraints are very strong for processes involving only electrons, muons or light quarks, Higgs couplings to top quarks and tau leptons can still be very large. In fact, the strongest limits on processes like t -> h q, h -> tau mu and h -> tau e are already coming from the LHC. We derive concrete bounds on h -> tau mu and h -> tau e by recasting the ATLAS search for h -> tau tau, and we demonstrate how a dedicated search for lepton flavour violating Higgs decays can achieve a substantially improved sensitivity even with existing data alone.
dias
June 3, 2013
**
Unleashing Feedback: Galaxies and AGN by Joe Silk (IAP, JHU & Oxford University)
**
Progress has been made in understanding the origin of spiral galaxies, but elliptical galaxy formation continues to pose unresolved problems. In both cases, feedback seems to be a central issue. I will review our understanding of feedback, on scales from stars to galaxies. I will focus on massive spheroids, where one invariably finds evidence for the presence of supermassive black holes. These are often visible, especially at early epochs, as active galactic nuclei. Negative feedback, due to the outflow from the central black hole during its accretion phase, quenches the gas supply to the spheroid. Is there an earlier period of feedback during protogalaxy formation that could result in an efficient phase of early black hole growth and star formation? Are there observational implications of AGN triggering of star formation? I will discuss some of these issues in this talk.
dias
November 5, 2012
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QCD resummation techniques applied to beyond the standard model physics by Benjamin Fuks (University of Strasbourg)
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When studying the transverse-momentum (pT) distribution of a produced colorless final state, it is convenient to separate the large- and small-pT regions. For the large values of pT, the use of the fixed-order perturbation theory is fully justified, but in the small-pT region, the coefficients of the perturbative expansion are enhanced by powers of large logarithmic terms. Furthermore, at the production threshold, the mismatch between virtual corrections and phase-space suppressed real-gluon emission leads also to the appearance of large logarithmic terms. Accurate theoretical calculations must then include soft-gluon resummation in order to obtain reliable perturbative predictions and properly take these logarithms into account. We present precision calculations for slepton-pair, gaugino-pair and Z’ production at hadron colliders, matching transverse-momentum spectra, invariant-mass distributions and total cross sections obtained with the use of resummation with those obtained through pure perturbative calculations. We compare then the resummed results with those provided by Monte Carlo generators such as MC@NLO, PYTHIA or MadGraph (including a matching a la MLM), and study the impact of scale variations, parton densities, and non-perturbative effects.
dias
October 12, 2012 at 11:30
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Ultra-High Energy Cosmic Rays III by Peter Tinyakov (Université Libre de Bruxelles)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 12, 2012 at 10:00
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Phenomenology of Technicolor III by Roshan Foadi (CP3, Université Catholique de Louvain)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 12, 2012 at 9:00
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Inﬂation and Cosmology Perturbations III by David Langlois (APC Paris)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 11, 2012 at 15:15
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Phenomenology of Technicolor II by Roshan Foadi (CP3, Université Catholique de Louvain)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 11, 2012 at 14:00
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Phases of Gauge Theories III by Thomas Ryttov (Jefferson Physical Laboratory, Harvard University)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 11, 2012 at 11:30
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Ultra-High Energy Cosmic Rays II by Peter Tinyakov (Université Libre de Bruxelles)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 11, 2012 at 10:00
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An Introduction to Dark Matter III by Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 11, 2012 at 9:00
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Inﬂation and Cosmology Perturbations II by David Langlois (APC Paris)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 10, 2012 at 11:30
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Inﬂation and Cosmology Perturbations I by David Langlois (APC Paris)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 10, 2012 at 10:00
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An Introduction to Dark Matter II by Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 10, 2012 at 9:00
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Supersymmetry and Supergravity III by Alex Kehagias (National Technical University of Athens)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 9, 2012 at 15:15
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Phenomenology of Technicolor I by Roshan Foadi (CP3, Université Catholique de Louvain)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 9, 2012 at 14:00
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An Introduction to Dark Matter I by Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 9, 2012 at 11:30
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Supersymmetry and Supergravity II by Alex Kehagias (National Technical University of Athens)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 9, 2012 at 10:00
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Supersymmetry and Supergravity I by Alex Kehagias (National Technical University of Athens)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 9, 2012 at 9:00
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Phases of Gauge Theories II by Thomas Ryttov (Jefferson Physical Laboratory, Harvard University)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 8, 2012 at 11:30
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Phases of Gauge Theories I by Thomas Ryttov (Jefferson Physical Laboratory, Harvard University)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 8, 2012 at 10:00
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Ultra-High Energy Cosmic Rays I by Peter Tinyakov (Université Libre de Bruxelles)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
October 8, 2012 at 9:45
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Winter School 2012 Opening Remarks by Chris Kouvaris (CP3-Origins)
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Talks Slides and Notes Roshan Foadi (CP3, Université Catholique de Louvain) Phenomenology of Technicolor (slides not available yet) Alex Kehagias (National Technical University of Athens): Notes on Supersymmetry and Supergravity David Langlois (APC Paris) Inﬂation and Cosmology Perturbations Thomas Ryttov (Jefferson Physical Laboratory, Harvard University): Phases of Gauge Theories Pasquale Serpico (Annecy Le Vieux Theoretical Physics Laboratory) An Introduction to Dark Matter - part I, part II, and part III Peter Tinyakov (Université Libre de Bruxelles) Ultra-High Energy Cosmic Rays Monday, October 8, 2012 Tuesday, October 9, 2012 Wednesday, October 10, 2012 Thursday, October 11, 2012 Friday, October 12, 2012
dias
May 24, 2012
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Cutoffs, Stretched Horizons and Black Hole Radiators by Nemanja Kaloper (UC Davis, California)
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We argue that if the UV cutoff of the IR theory is of the order, or below, the scale of the stretched horizon in a black hole background, which in turn is significantly lower than the Planck scale, the black hole radiance is controlled by the UV completion of the field theory. In particular, if the UV completion of the theory involves degrees of freedom which cannot be efficiently emitted by the black hole, the naive radiance rate estimated by the counting of the IR degrees of freedom may be dramatically reduced. If we apply this argument to the RS2 brane world, it implies that the emission rates of the low energy CFT modes will be dramatically suppressed: its UV completion is given by the bulk gravity on $AdS_5 \times S^5$, and the only bulk modes that could be emitted by a black hole are the s-waves of bulk modes with small 4D masses. But their emission is suppressed by bulk warping. This lowers the radiation rate much below the IR estimate, and follows directly from low CFT cutoff $\mu \sim L^{-1} \ll M_{Pl}$, a large number of modes $N \gg 1$ and the fact that 4D gravity in RS2 is induced, $M_{Pl}^2 \simeq N \mu^2$.
dias
December 8, 2011
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1st CP3 meeting on ethics and responsible conduct in research by Dominique Bouchet
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Professor Dominique Bouchet from the Department of Marketing and Management, SDU, will give a seminar introducing the ethical implications of being researcher and the consequences of misconduct in research. Science and scientific research have, today more than ever, a huge impact on society, culture, and on the way people perceive themselves and the reality around them. For this reason, scientists have big responsibilities and must perform their work as fairly as possible. Any negligence could have enormous consequences on other researcher’s work and on technology development, it causes financial losses and it constitutes a threat to the level of thrust attributed to research in general. Recently the media focused on a serious case of misconduct in scientific research that happened in Denmark, involving falsification of research data. Although being an extreme behaviour, intentional acts like these do not exhaust the list of possible negligences in research. In fact sometimes people do wrong even when they do not mean to, just because they are not properly aware of the implications and consequences of their behaviour. We decided therefore to go deeper in our understanding of the implications of our job, to get more self-awareness and work in a more responsible and conscious way. See also the related news for further details.
dias
August 4, 2011
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Flavour Physics Beyond the Standard Model by Federico Mescia (University of Barcelona)
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I will present a summary of what we learned so far from low-energy flavour-quark observables, concerning physics beyond the Standard Model (SM). In the last few years there has been a great experimental progress in quark and lepton flavour physics. In the quark sector, the validity of the SM has been strongly reinforced by a series of challenging tests. More important, several suppressed observables (such as DMBs, sin(2beta), epsK, b->sgamma) potentially sensitive to New Physics (NP) have been measured with good accuracy, showing no deviations from the SM. In constructing a realistic SM extension we should then try to reconcile many non-trivial constraints. The Minimal Flavour Violation hypothesis well handles flavour-quark data and shows, in the large tanbeta scenario, interesting effects to be detected by LHCB.
dias
June 14, 2011
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Dark Energy and the Cosmological Constant Problem by Florian Bauer (Barcelona University)
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Abstract: The currently observed acceleration of the universe may originate from "dark energy", a new component in the energy content of the cosmos. A tiny positive cosmological constant would be the simplest solution, however, it is usually rejected because our well-working particle physics theories suggest a much larger magnitude than observed. Therefore, other sources of acceleration have been considered, e.g. scalar fields, modified gravity, back reaction effects or a misinterpretation of observations. In these setups the cosmological constant is usually set to zero, and the problem is ignored. Different from that, I will discuss some scenarios that aim at providing low curvature solutions despite the existence of a large cosmological constant.
dias
November 2, 2010 at 16:00
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Black Holes in Elementary Physics by Gerard ‘t Hooft (Utrecht University)
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Abstract In Physics, black holes are known as extremely dense forms of matter, of which, from the outside, only the gravitational force can be detected. Astronomers observe such object ate various spots in the Universe. When in laboratories on earth elementary particles are made to collide with the strongest possible force, these collisions are by far not energetic enough to produce black holes. However, we can try to imagine collisions that are so energetic that black holes do form, and then ask ourselves what exactly might happen then. The question is important because it turns out that our theoretical understanding falls short at this point. The gravitational force is so special that all beautiful theories we have today about the particles and the forces between them cannot describe it. Do black holes obey the laws of quantum mechanics? Are black holes also subatomic particles and vice versa? If so, our theories must be revised. This can lead to fundamental new insights about very basic features in physics, and give us new tools to describe space, time, and matter. Professor Gerard 't Hooft Professor Gerard 't Hooft is a theoretical physicist at Utrecht University, the Netherlands. He shared the 1999 Nobel Prize in Physics with Martinus J. G. Veltman for elucidating the quantum structure of electroweak interactions. He was awarded the Lorentz Medal in 1986 and the Spinozapremie in 1995. Public Lecture Prof. 't Hooft gives a lecture on Black Holes in Elementary Physics. The lecture is intended for the general public. Everybody is welcome to attend. You do not need to register for the lecture, and entrance is free. Refreshments will be served before the lecture. More Information The Nobel Lecture is held together with the 3rd Odense Winter School on Geometry and Theoretical Physics - look at the home page of the winter school for travel information, accommodation, etc. Poster A PDF version of our poster can be found by following this link. Media
dias
October 26, 2009
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Topology and the Universe by Berian James (DARK, Copenhagen)
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In recent decades, astronomical observations have led to a broad, if incomplete, consensus description of the large-scale Universe: its evolution is determined by a handful of substances ('usual' matter like atoms, stars and galaxies; a hidden, but gravitationally attractive dark matter; the poorly understood and unfortunately named dark energy) all of which are changing under the influence of physical laws. In the region of the Universe visible to astronomers, great cosmological structures are observed---dense clusters in which the majority of galaxies form; vast and apparently empty voids; and a tangle of filaments that has been coined 'the cosmic web'. In this talk, I explore the role that topology, the mathematics of shape, plays in defining our understanding of the Universe. After reviewing the relationship between geometry and dynamics that characterises the modern Big Bang theory, I discuss three topics of broad scope: i) the classification of cosmological structures as a means of understanding both the physics of the very early Universe and the evolution and formation of galaxies; ii) the impact of some modern mathematical results from differential geometry that have yet to be fully assimilated into physics; and iii) the theory and measurements of the global topology of the Universe---does it extend infinitely in all directions, or wrap-around on itself, and how can we tell? Due to technical reasons the first few minutes of the talk are unfortunately missing from the recording.