PT Journal
AU Ren, XL
   Alvarez-Ruso, L
   Geng, LS
   Ledwig, T
   Meng, J
   Vicente Vacas, MJ
TI Consistency between SU(3) and SU(2) covariant baryon chiral perturbation theory for the nucleon mass
SO Physics Letters B
JI Phys. Lett. B
PY 2017
BP 325
EP 333
VL 766
DI 10.1016/j.physletb.2017.01.024
LA English
DE Baryon chiral perturbation theory; Lattice QCD; Nucleon mass and sigma term
AB 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 19low-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 19couplings) 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 n(f) = 2 + 1lattice QCD simulations as long as the strange quark mass is close to its physical value.
ER