Renormalization of the baryon axial vector current in large-Ncchiral perturbation theory

Abstract

The baryon axial vector current is computed at one-loop order in heavy baryon chiral perturbation theory in the large-${N}_{c}$ limit, where ${N}_{c}$ is the number of colors. Loop graphs with octet and decuplet intermediate states cancel to various orders in ${N}_{c}$ as a consequence of the large-${N}_{c}$ spin-flavor symmetry of QCD baryons. These cancellations are explicitly shown for the general case of ${N}_{f}$ flavors of light quarks. In particular, a new generic cancellation is identified in the renormalization of the baryon axial vector current at one-loop order. A comparison with conventional heavy baryon chiral perturbation theory is performed at the physical values ${N}_{c}=3$, ${N}_{f}=3$.