Formula omitted] in the massive Schwinger model with Wilson fermions

Abstract

The chiral condensate 〈 ψψ〉 is calculated in a numerical simulation of the massive Schwinger model with Wilson fermions using the pseudofermion method. The free theory is used to check the pseudofermion method showing that it works well except near the zero mode caused by periodic boundary conditions. In the quenched model 〈 ψψ〉 agrees with the prediction of Carson and Kenway that it diverges logarithmically as the physical mass tends to zero; this determines the critical mass. In the dynamical model the exact massless result for 〈 ψψ〉 is used to obtain the critical mass and hence the behaviour of 〈 ψψ〉 with physical mass.