Quark mass dependence of nucleon mass and axial-vector coupling constant

TL;DR

This paper analyzes how quark masses influence nucleon properties, comparing different chiral effective theories and emphasizing the importance of delta (1232) degrees of freedom for accurately modeling the axial-vector coupling constant.

Contribution

It provides an updated analysis of nucleon mass and g_A dependence on quark masses, highlighting the role of explicit delta (1232) degrees of freedom in chiral extrapolations.

Findings

Including delta (1232) is crucial for g_A interpolation.

Nucleon mass interpolation is less sensitive to delta (1232).

Chiral extrapolation aligns lattice data with physical values.

Abstract

We present an updated analysis of the quark mass dependence of the nucleon mass and nucleon axial-vector coupling g_A, comparing different formulations of SU(2) Baryon Chiral Effective Field Theory, with and without explicit delta (1232) degrees of freedom. We discuss the outcome of the corresponding interpolations between lattice QCD data and the physical values for these two nucleon observables. It turns out that in order to obtain successful interpolating functions at one-loop order, the inclusion of explicit delta (1232) degrees of freedom is not decisive for the nucleon mass but crucial for g_A. A chiral extrapolation of recent lattice results by the LHP collaborations is also shown.