Gauge theories with fermions in the two-index symmetric representation

TL;DR

This paper reviews recent studies on gauge theories with fermions in the two-index symmetric representation, highlighting their near-conformal behavior and small mass anomalous dimensions across different gauge groups.

Contribution

It provides a comparative summary of nonperturbative results for multiple gauge theories with two-index symmetric fermions, emphasizing their approach to fixed points.

Findings

Beta functions are smaller than perturbative predictions.

All systems have small mass anomalous dimensions, under 0.5.

The theories approach a fixed point near the two-loop zero.

Abstract

We summarize our recent work on gauge theories with two flavors of fermions in the two-index symmetric representation: SU(2) gauge theory with adjoint fermions, SU(3) with sextets, and SU(4) with ten-dimensional-representation fermions. All three systems have beta functions smaller than their perturbative value, approaching a fixed point near the expected two-loop zero. In all cases the mass anomalous dimension is small, under 0.5.