Topics on heavy baryon chiral perturbation theory in the large N_c limit

Abstract

We compute nonanalytical pion-loop corrections to baryon masses in a combined expansion in chiral symmetry breaking and 1/N_c, where N_c is the number of colors. Specifically, we compute flavor-27 baryon mass splittings at leading order in chiral perturbation theory. Our results, at the physical value N_c=3, are compared with the expressions obtained in heavy baryon chiral perturbation theory with no 1/N_c expansion.

Comments: 7 pages. Based on a talk given at 8th Mexican Workshop on Particles and Fields, Zacatecas, Mexico, 14-20 Nov 2001. To appear in the proceedings