Fundamental representations – Partially Gauged Technicolor

Project Coordinator: Edinburgh University

Partners: CP3-Origins, LNF, Oxford University, University of Groningen, Jyväskylä University

This WP aims at phenomenological objectives similar to the WP1, namely to combine phenomenological studies and lattice results to identify clear signals of new physics that could unveil partially gauged technicolor at the LHC. The lattice investigation will take into account the fact that the fermions belong to the fundamental representation rather than the higher ones.

Task 1: Collider physics and cosmological applications

Before embarking in studying a strong dynamical model on the lattice one should consider their relevance for physical applications. Several analytical studies indicate that these theories can reach an infrared fixed point only for a very large number of flavors. Precision electroweak data, however, count, in first approximation – if all the flavors are gauged under the electroweak theory -, these flavors. A large number of techniflavors disfavors one-family technicolor models. Gauging, however, only two flavors reduces the corrections to the precision data making these models still viable. These models are known as Partially Gauge Technicolor [PGT] models. We will investigate the models signatures for collider physics and cosmology.

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

We will start with the  theory with eight fundamental flavors which has been extensively studied in past work at nonzero temperature and density. Methodology will be the same as for three colors, possibly supplemented by a cross check with Renormalization Group (RG) methods which are particularly simple for two colors. We will built on the expertise gained on the thermodynamics of the model to completely characterize the phase diagram in the Nf, chemical potential, temperature plane.

Task 3: Lattice explorations of the dynamics of SU(3) with Fundamental matter

The study of the phase diagram with fundamental fermions will use extensive calculations of the mass spectrum and of the order parameter. The analysis will be inspired by the phenomenological work as well as by past experiences of strongly coupled, symmetric systems such as QED and the symmetric phase of ordinary QCD. A few theories with fixed number of flavors – 6, 8, 10, 12, 14 – will be studied in detail, in order to reconstruct the full phase diagram in the Nf, g plane. The continuum limit of the chiral condensate, mass gap and critical temperature will be computed in the near conformal region, aiming at a complete characterization of the walking dynamics.

Milestones:

  1. Write the low energy effective theories and identify interesting signals for the LHC. Timeframe: 8 m.
  2. Mapping of the finite-temperature phase diagram for different numbers of flavors for SU(2) and/or SU(3) via lattice computations. Timeframe: 24 m.
  3. Determination of the non-perturbative beta function and anomalous dimensions of the SU(2)/SU(3) theory. Timeframe: 12 m.
  4. Computation of the mass spectrum of SU(2) or SU(3) theory and study of systematic errors. Timeframe: 12 m.