Lowest-lying octet baryon masses in covariant baryon chiral perturbation theory

We report on a systematic study of the ground-state octet baryon masses in the covariant baryon chiral perturbation theory with the extended-on-mass-shell renormalization scheme up to next-to-next-to-next-to-leading order, taking into account the contributions of the virtual decuplet baryons. A reasonable description of the lattice results is achieved by fitting simultaneously all the publicly available $n_f=2+1$ lattice QCD data. It confirms that the various lattice simulations are consistent with each other. We stress that a self-consistent treatment of finite-volume corrections is important to obtain a ${\chi }^2\mathrm{/}\mathrm{d}\mathrm{.}\mathrm{o}\mathrm{.}\mathrm{f}\mathrm{.}$ about 1.