Pion and nucleon in two flavour QCD with unimproved Wilson fermions

TL;DR

This study performs lattice QCD simulations with unimproved Wilson fermions to compute pion and nucleon properties, finding negligible cutoff effects and qualitative agreement with chiral perturbation theory.

Contribution

First comprehensive lattice QCD analysis of pion and nucleon masses using unimproved Wilson fermions at multiple lattice spacings and volumes.

Findings

Cutoff effects are negligible in pion and nucleon masses.

Chiral behaviors align qualitatively with NLO chiral perturbation theory.

Simulations cover various quark masses and lattice parameters.

Abstract

We calculate pion mass, pion decay constant, PCAC quark mass and nucleon mass in two flavour lattice QCD with unimproved Wilson fermion and gauge actions. Simulations are performed using DD-HMC algorithm at two lattice spacings and two volumes for several values of the quark mass. The cutoff effects in pion mass and nucleon mass for the explored region of parameter space are found to be negligible. The chiral behaviours of pion mass, pion decay constant and quark condensate are found to be qualitatively consistent with NLO chiral perturbation theory.