Baryon currents in QCD with compact dimensions

TL;DR

This paper investigates how SU(N) gauge theories with fermions in compact spaces exhibit spontaneous breaking of discrete symmetries, evidenced by a non-zero baryonic current, confirmed through both perturbative calculations and lattice simulations.

Contribution

It demonstrates the existence of a baryonic current as a physical signature of symmetry breaking in QCD with compact dimensions, combining perturbative and lattice approaches.

Findings

Non-zero baryonic current appears at small compactification radii.

Charge conjugation, parity, and time reversal symmetries are spontaneously broken.

Lattice simulations support the persistence of the baryonic current beyond perturbation theory.

Abstract

On a compact space with non-trivial cycles, for sufficiently small values of the radii of the compact dimensions, SU(N) gauge theories coupled with fermions in the fundamental representation spontaneously break charge conjugation, time reversal and parity. We show at one loop in perturbation theory that physical signature for this phenomenon is a non-zero baryonic current wrapping around the compact directions. The persistence of this current beyond the perturbative regime is checked by lattice simulations.