On finite volume effects in the chiral extrapolation of baryon masses

الأصل · EN

We perform an analysis of the QCD lattice data on the baryon octet and decuplet masses based on the relativistic chiral Lagrangian. The baryon self energies are computed in a finite volume at next-to-next-to-next-to leading order (N³LO), where the dependence on the physical meson and baryon masses is kept. The number of free parameters is reduced significantly down to 12 by relying on large-Nc sum rules. Altogether we describe accurately more than 220 data points from six different lattice groups, BMW, PACS-CS, HSC, LHPC, QCDSF-UKQCD and NPLQCD. Values for all counter terms relevant at N³LO are predicted. In particular we extract a pion-nucleon sigma term of 39₋₁⁺² MeV and a strangeness sigma term of the nucleon of σsN = 84⁺ ²⁸₋₄ MeV. The flavour SU(3) chiral limit of the baryon octet and decuplet masses is determined with (802 ± 4) MeV and (1103 ± 6) MeV. Detailed predictions for the baryon masses as currently evaluated by the ETM lattice QCD group are made.