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

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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 nf = 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 O(a²) can be safely ignored, but the finite volume corrections cannot even for configurations with MϕL>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 σπₙ = 55(1)(4) MeV and σsN = 27(27)(4) MeV, respectively.