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

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-Tonext-To-leading order. To take into account lattice QCD artifacts, the finite-volume corrections and finite lattice spacing discretization effects are carefully examined. We perform a simultaneous fit of all the nf = 2+1 lattice octet baryon masses and find that the various lattice simulations are consistent with each other. Although the finite lattice spacing discretization effects up to δ(a²) can be safely ignored, the finite volume corrections cannot even for configurations with MφL > 4. As an application, we predict the octet baryon sigma terms using the Feynman-Hellmann theorem. In particular, the pion-And strangeness-nucleon sigma terms are found to be σπN =55(1)(4) MeV and σ&sN = 27(27)(4) MeV, respectively.