Consistency between SU(3) and SU(2) covariant baryon chiral perturbation theory for the nucleon mass

Autor: Xiu-Lei Ren, L. Alvarez-Ruso, Li-Sheng Geng, Tim Ledwig, Jie Meng, M.J. Vicente Vacas
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Physics Letters B, Vol 766, Iss C, Pp 325-333 (2017)
Druh dokumentu: article
ISSN: 0370-2693
1873-2445
DOI: 10.1016/j.physletb.2017.01.024
Popis: 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 19 low-energy constants appearing in the octet baryon masses up to next-to-next-to-next-to-leading order [1] is supported by comparing the effective parameters (the combinations of the 19 couplings) with the corresponding low-energy constants in the SU(2) sector [2]. 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. [2] that the SU(2) baryon chiral perturbation theory can be applied to study nf=2+1 lattice QCD simulations as long as the strange quark mass is close to its physical value.
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