Chiral condensate from the twisted mass Dirac operator spectrum

TL;DR

This paper computes the chiral condensate using twisted mass fermions and spectral methods, analyzing effects of strange and charm quarks across multiple lattice spacings and quark masses.

Contribution

It applies the spectral projector method to determine the chiral condensate for different dynamical flavor configurations and performs chiral and continuum extrapolations.

Findings

Consistent chiral condensate values for Nf=2 and Nf=2+1+1.

Quantitative analysis of strange and charm quark effects.

Results across three lattice spacings and multiple quark masses.

Abstract

We present the results of our computation of the chiral condensate with $N_f=2$ and $N_f=2+1+1$ flavours of maximally twisted mass fermions. The condensate is determined from the Dirac operator spectrum, applying the spectral projector method proposed by Giusti and Luscher. We use 3 lattice spacings and several quark masses at each lattice spacing to perform the chiral and continuum extrapolations. We study the effect of the dynamical strange and charm quarks by comparing our results for $N_f=2$ and $N_f=2+1+1$ dynamical flavours.