Confinement study of an SU(4) gauge theory with fermions in multiple representations

Venkitesh Ayyar,Ethan T Neil,Daniel C Hackett,William I Jay

doi:10.1051/epjconf/201817508025

Abstract

We discuss the phase diagnostics used in our finite-temperature study of an SU(4) gauge theory with dynamical fermions in both the fundamental and two-index antisymmetric representations. Beyond the usual Polyakov loop diagnostics of confinement, we employ several Wilson flow phase diagnostics. The first, what we call the ‘‘flow anisotropy’’, is known in the literature: the deconfinement transition introduces anisotropy between the spatial and temporal directions, to which the flow is extremely sensitive. The second, the ‘‘long flow time Polyakov loop,’’ is related but novel. While we do not claim to fully understand this diagnostic, we have empirically found it to be useful as an unusually sharp diagnostic of phase.

Highlights

Coupled theories with fermions charged under different representations have been proposed as Beyond Standard Model candidates, in the context of Composite Higgs [1, 2] and partial compositeness [3]
In this work we explore one such lattice BSM model [4, 5], an SU(4) gauge theory with fermions in the fundamental (F, 4, quartet) and two-index antisymmetric (A2, 6, sextet) representations
We present our study of the phase diagram at finite-temperature in a companion Proceedings [6]. In these Proceedings, we would like to present the various confinement phase diagnostics employed in our study

Summary

Introduction

Coupled theories with fermions charged under different representations have been proposed as Beyond Standard Model candidates, in the context of Composite Higgs [1, 2] and partial compositeness [3]. In this work we explore one such lattice BSM model [4, 5], an SU(4) gauge theory with fermions in the fundamental (F, 4, quartet) and two-index antisymmetric (A2, 6, sextet) representations. We discuss a few Wilson flow phase diagnostics. We propose a new confinement diagnostic, the Polyakov loop at long Wilson flow times. With fermions in two representations, we can construct Polyakov loops for each representation and look for confinement in each sector separately. In this theory, the confinement transitions for both representations are found to coincide. We focus on diagnosing confinement in the fundamental sector only

Flow Anisotropy Diagnostic

Polyakov Loops at Long Flow Time Diagnostic

Possible Mechanism