The nucleon mass in N_f=2 lattice QCD: finite size effects from chiral perturbation theory

TL;DR

This paper uses chiral perturbation theory to predict finite size effects on the nucleon mass in lattice QCD, and compares these predictions with recent lattice simulation data, finding remarkable agreement.

Contribution

It provides a parameter-free prediction of finite size effects on the nucleon mass using chiral perturbation theory and validates it against recent lattice QCD data.

Findings

Lattice data agrees well with chiral perturbation theory predictions.

Finite size effects on nucleon mass are accurately modeled.

Parameter-free predictions match observed data.

Abstract

In the framework of relativistic SU(2)_f baryon chiral perturbation theory we calculate the volume dependence of the nucleon mass up to and including O(p^4). Since the parameters in the resulting finite size formulae are fixed from the pion mass dependence of the large volume nucleon masses and from phenomenology, we obtain a parameter-free prediction of the finite size effects. We present mass data from the recent N_f=2 simulations of the UKQCD and QCDSF collaborations and compare these data as well as published mass values from the dynamical simulations of the CP-PACS and JLQCD collaborations with the theoretical expectations. Remarkable agreement between the lattice data and the predictions of chiral perturbation theory in a finite volume is found.