(Ultra) Minimal Walking Technicolor

Project Coordinator: CP3-Origins

Partners: Edinburgh University, Helsinki University, Tel Aviv University, Oxford University, Swansea University, Jyväskylä University, Rensselaer Polytechnic

Combine phenomenological studies and lattice results to investigate clear signals of new physics that could unveil a Minimal Walking theory at the LHC.

Task 1: Collider physics and cosmological applications

We plan to investigate the LHC and Linear collider signatures of models of dynamical electroweak symmetry breaking with flavor symmetry respecting the one of Minimal, Next to Minimal and Ultra Minimal Walking Technicolor. These models are denoted in short by (N)MWT and UMT, respectively. This is performed using low energy effective theories incorporating the correct symmetries. Besides, MWT and UMT feature several different types of Technicolor Interacting Massive Particles (TIMP)s which are shown to be excellent candidates for cold Dark Matter of asymmetric type. We plan to investigate the early universe production mechanism and its interplay with the production of the ordinary baryon asymmetry. The TIMPs can be relatively light (some of them are pseudogoldtone bosons) with respect to the electroweak scale and hence the TIMP production at the LHC will also be investigated.

Task 2: Lattice explorations of the dynamics of SU(2) with Adjoint matter

We will further explore the finite temperature physics of this theory and of the SU(3) theory, motivated partly by old observations of separate temperatures for deconfinement and chiral symmetry breaking in the SU(3) theory with two adjoint fermions. The possibility of two different phase transitions is also very relevant for the early universe evolution and possible impact on gravitational waves observations. We will attempt to develop a general analytic framework for the conformal symmetry breaking induced by the lattice discretization and finite volume effects for (near-)conformal field theories, of the kind that exists and is very useful for gauge theories with a mass gap.

Task 3: Lattice explorations of the dynamics of SU(3) with 2-index Symmetric Representation

Lattice studies indicate that this theory is near the borderline between a confining and a conformal low energy limit, and “walking” is a distinct possibility. We will apply the various numerical tools of lattice gauge theory to settle this question, including determination of the phase diagram in the coupling-mass-temperature axes, calculation of the running coupling with the Schroedinger functional method, and calculation of anomalous dimensions. An ESR will calculate improvement and renormalization coefficients numerically, to see whether the in- teresting parts of the lattice phase diagram are relevant to the continuum limit.

Task 4: Lattice explorations of the dynamics of SU(2) with multiple representations

UMT is an explicit example of a BSM model featuring fermions of two species. One species transforming according to the fundamental representation of the new gauge group SU(2) and the other according to the adjoint representation. We intend to initiate the lattice investigation of the structure of SU(2) featuring two fundamental Dirac flavors and one Dirac adjoint flavor and assess whether it is possible to use such models to construct walking gauge theories suitable for breaking electroweak symmetry in a technicolor-like scenario featuring a natural TIMP.

Milestones:

  1. Investigation of the production mechanisms of TIMPs in the MWT and UMT models. Timeframe: 8 m.
  2. Mapping of the finite-temperature phase diagram of the MWT theory via lattice computations. Time- frame: 8 m.
  3. Mapping of the finite-temperature phase diagram of the NMWT theory. Timeframe: 8 m.
  4. Determination of the non-perturbative beta function and anomalous dimensions of the UMWT theory. Timeframe: 10 m.
  5. Initial investigation of the phase diagram of the UMT model on the lattice and determination of the lo- cation of lattice bulk transitions. Timeframe: 3 m.
  6. Computation of the mass spectrum of the UMT theory and identification of candidate TIMPs. Timeframe: 10 m.