Baryon masses, chiral extrapolations, and all that

TL;DR

This paper calculates baryon octet masses using chiral perturbation theory up to fourth order, analyzing pion and kaon mass dependencies with lattice data, and provides insights into chiral extrapolations and sigma terms.

Contribution

It extends chiral perturbation theory calculations to fourth order for baryon masses and assesses stability of extrapolations using MILC data.

Findings

Chiral extrapolation functions are stable below specific meson masses.

The pion-nucleon sigma term is estimated to be around 50.7 to 53.7 MeV.

Chiral perturbation theory effectively describes baryon masses within certain mass ranges.

Abstract

We calculate the baryon octet masses to fourth order in chiral perturbation theory employing dimensional and cut-off regularization. We analyze the pion and kaon mass dependences of the baryon masses based on the MILC data. We show that chiral perturbation theory gives stable chiral extrapolation functions for pion (kaon) masses below 550 (600) MeV. The pion-nucleon sigma term in SU(3) is also investigated, we find \sigma_{\pi N} (0) = 50.7 - 53.7 MeV.