Nucleon mass: from lattice QCD to the chiral limit

Previous extrapolations of lattice QCD results for the nucleon mass to the physically relevant region of small quark masses, using chiral effective field theory, are extended and expanded in several directions: a detailed error analysis is performed; the consistency with the chiral perturbation theory analysis of pion-nucleon scattering data is examined; the dependence on finite lattice volume is investigated; the role of explicit delta(1232) degrees of freedom is explored. What emerges is a consistent and stable extrapolation scheme for pion masses below 0.6 GeV