One flavour adjoint QCD with overlap fermions

TL;DR

This paper investigates the infrared behavior of one-flavor adjoint QCD using overlap fermions, providing evidence for chiral symmetry breaking and suggesting the theory is not conformal in the studied energy range.

Contribution

First study of adjoint QCD with one flavor using overlap fermions to avoid chiral symmetry breaking artifacts, analyzing chiral symmetry and running coupling.

Findings

Evidence of spontaneous chiral symmetry breaking

No indication of infrared conformality in the explored energy range

Overlap fermions effectively preserve chiral symmetry in simulations

Abstract

The infrared effective theory of adjoint QCD with one Dirac flavour is still under debate. The theory could be confining, conformal, or with a massless fermion in the infrared. The study of chiral symmetry seems to be important to answer this question. While previous investigations have considered Wilson fermions, we present here the first results for this theory based on overlap fermions to avoid explicit chiral symmetry breaking. These indicate spontaneous chiral symmetry breaking by the formation of a fermion condensate. We have also investigated the running coupling of the theory, which indicates no infrared conformality in the energy region we have explored.