Hyperon sigma terms for 2+1 quark flavours

TL;DR

This paper introduces a novel lattice QCD method to determine hyperon sigma terms by maintaining a constant singlet quark mass, simplifying the extraction process and avoiding complex chiral perturbation theory.

Contribution

It presents a new approach using SU(3) flavor symmetry breaking expansion with constant singlet quark mass for more precise hadron mass gradient determination.

Findings

Estimated light and strange sigma terms for the baryon octet.

Demonstrated the effectiveness of the constant singlet quark mass method.

Provided constraints on hadron mass fits using fewer parameters.

Abstract

QCD lattice simulations determine hadron masses as functions of the quark masses. From the gradients of these masses and using the Feynman-Hellmann theorem the hadron sigma terms can then be determined. We use here a novel approach of keeping the singlet quark mass constant in our simulations which upon using an SU(3) flavour symmetry breaking expansion gives highly constrained (i.e. few parameter) fits for hadron masses in a multiplet. This is a highly advantageous procedure for determining the hadron mass gradient as it avoids the use of delicate chiral perturbation theory. We illustrate the procedure here by estimating the light and strange sigma terms for the baryon octet.