arXiv:1606.03820·v2·Nuclear Theory
Consistency between SU(3) and SU(2) chiral perturbation theory for the nucleon mass
Xiu-Lei Ren (Beihang U. & Peking U., SKLNPT)🇨🇳 · L. Alvarez-Ruso (Valencia U., IFIC)🇪🇸 · Li-Sheng Geng (Beihang U.)🇨🇳 · T. Ledwig (Valencia U., IFIC)🇪🇸 · Jie Meng (Beihang U. & Peking U., SKLNPT & Stellenbosch U.)🇨🇳 · M.J. Vicente Vacas (Valencia U. & Valencia U., IFIC)🇪🇸
Abstract
Treating the strange quark mass as a heavy scale compared to the light quark mass, we perform a matching of the nucleon mass in the SU(3) sector to the two-flavor case in covariant baryon chiral perturbation theory. The validity of the low-energy constants appearing in the octet baryon masses up to next-to-next-to-next-to-leading order~\cite{Ren:2014vea} is supported by comparing the effective parameters (the combinations of the couplings) with the corresponding low-energy constants in the SU(2) sector~\cite{Alvarez-Ruso:2013fza}. In addition, it is shown that the dependence of the effective parameters and the pion-nucleon sigma term on the strange quark mass is relatively weak around its physical value, thus providing support to the assumption made in Ref.~\cite{Alvarez-Ruso:2013fza}.
Comments: 11 pages, 1 table, 6, added reference, a few points clarified, matches the version accepted for publication