Anomaly at finite density and chiral fermions on lattice

TL;DR

This paper verifies that the chiral anomaly remains unchanged at finite chemical potential in continuum QCD and discusses implications for lattice fermions with exact chiral symmetry, proposing a new method for including chemical potential.

Contribution

It provides a non-perturbative verification of anomaly invariance at finite density and introduces a simpler approach for incorporating chemical potential in lattice fermion formulations.

Findings

Chiral anomaly is unaffected by finite chemical potential in continuum QCD.

Analysis of lattice fermions with exact chiral symmetry at finite density.

Proposal of a new, simpler method to incorporate chemical potential in lattice simulations.

Abstract

Using both perturbation theory in the Euclidean formalism as well as the non-perturbative Fujikawa's method, we verify that the chiral anomaly equation remains unaffected in continuum QCD in the presence of nonzero chemical potential, \mu. We extend our considerations to lattice fermions with exact chiral symmetry and discuss the consequences for the recent Bloch-Wettig proposal for the Dirac operator at finite chemical potential. We propose a new simpler method of incorporating \mu.