Octet baryon masses and sigma terms in covariant baryon chiral perturbation theory

Abstract

We report on a recent study of the ground-state octet baryon masses and sigma terms in covariant baryon chiral perturbation theory with the extended-on-mass-shell scheme up to next-to-next-to-next-to-leading order. To take into account lattice QCD artifacts, the finite-volume corrections and finite lattice spacing discretization effects are carefully examined. We performed a simultaneous fit of all the $n_f=2+1$ lattice octet baryon masses and found that the various lattice simulations are consistent with each other. Although the finite lattice spacing discretization effects up to $\mathcal{O}(a^2)$ can be safely ignored, but the finite volume corrections cannot even for configurations with $M_{\ddot{I}}•L>4$. As an application, we predicted the octet baryon sigma terms using the Feynman-Hellmann theorem. In particular, the pion- and strangeness-nucleon sigma terms are found to be $\ddot{I}{ƒ}_{\ddot{I}€N}=55(1)(4)$ MeV and $\ddot{I}{ƒ}_{sN}=27(27)(4)$ MeV, respectively.

8 pages, 3 figures; presented by Xiu-Lei Ren at The 8th International Workshop on Chiral Dynamics (CD2015), 29 June 2015 - 03 July 2015, Pisa, Italy. Final published version. Latest results of sigma terms are shown in Fig.3. arXiv admin note: text overlap with arXiv:1405.4990