Chiral extrapolations and strangeness in the baryon ground states

TL;DR

This paper analyzes how baryon masses depend on quark masses using lattice QCD data and chiral perturbation theory, providing a unified fit and insights into sigma terms, with implications for understanding baryon structure.

Contribution

It offers a comprehensive analysis of baryon mass dependence on quark masses using a six-parameter fit to lattice data within a relativistic chiral framework, including large-Nc estimates.

Findings

Baryon masses show approximate linear dependence on pion mass above 300 MeV.

A successful simultaneous fit reproduces lattice results with a six-parameter model.

Discussion of pion- and strangeness sigma terms enhances understanding of baryon structure.

Abstract

We review the quark-mass dependence of the baryon octet and decuplet masses as obtained from recent lattice simulations of the BMW, PACS-CS, LHPC, HSC and QCDSF-UKQCD groups. Our discussion relies on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. In our analysis the physical masses are reproduced exactly by means of a suitable set of linear constraints. A quantitative and simultaneous description of all lattice results is achieved in terms of a six parameter fit, where the symmetry conserving counter term that are relevant at N$^3$LO are not yet being used. For pion masses larger than 300 MeV there appears to be an approximate linear pion-mass dependence of all octet and decuplet baryon masses. We discuss the pion- and strangeness sigma terms of the baryon octet states.