Octet baryon masses in next-to-next-to-next-to-leading order covariant baryon chiral perturbation theory

TL;DR

This paper employs covariant baryon chiral perturbation theory up to N$^3$LO to accurately fit lattice QCD data for octet baryon masses and predict sigma terms, improving understanding of baryon mass evolution.

Contribution

It introduces a high-order (N$^3$LO) covariant BChPT approach with extended-on-mass-shell scheme to fit lattice QCD results and predict sigma terms, advancing baryon mass modeling.

Findings

N$^3$LO BChPT fits lattice data better than NNLO.

Predicted sigma terms: σ_{πN}=43(1)(6) MeV, σ_{sN}=126(24)(54) MeV.

Lattice simulations are consistent with each other.

Abstract

We study the ground-state octet baryon masses and sigma terms using the covariant baryon chiral perturbation theory (ChPT) with the extended-on-mass-shell (EOMS) renormalization scheme up to next-to-next-to-next-to-leading order (N$^3$LO). By adjusting the available 19 low-energy constants (LECs), a reasonable fit of the $n_f=2+1$ lattice quantum chromodynamics (LQCD) results from the PACS-CS, LHPC, HSC, QCDSF-UKQCD and NPLQCD collaborations is achieved. Finite-volume corrections to the lattice data are calculated self-consistently. Our study shows that N$^3$LO BChPT describes better the light quark mass evolution of the lattice data than the NNLO BChPT does and the various lattice simulations seem to be consistent with each other. We also predict the pion and strangeness sigma terms of the octet baryons using the LECs determined in the fit of their masses. The predicted pion- and strangeness-nucleon sigma terms are $\sigma_{\pi N}=43(1)(6)$ MeV and $\sigma_{s N}=126(24)(54)$ MeV, respectively.