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

We report an analysis of the octet baryon masses using the covariant baryon chiral perturbation theory up to next-to-next-to-next-to-leading order with and without the virtual decuplet contributions. Particular attention is paid to the finite-volume corrections and the finite lattice spacing effects on the baryon masses. A reasonable description of all the publicly available n_f = 2 + 1 lattice QCD data is achieved. Utilyzing the Feynman-Hellmann theorem, we determine the nucleon sigma terms as σ_πN = 55(1)(4) Mev and σ_sN = 27(27)(4) MeV.