s -wave baryon nonleptonic decay amplitude in large−Nc chiral perturbation theory

The $s$-wave decay amplitude in the nonleptonic decay of baryons is analyzed within heavy baryon chiral perturbation theory in the $\mathrm{large}\text{\ensuremath{-}}{N}_{c}$ limit at one-loop order, where ${N}_{c}$ is the number of color charges. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis and the effects of the decuplet-octet mass difference are accounted for. There are $\mathrm{large}\text{\ensuremath{-}}{N}_{c}$ cancellations between different one-loop graphs as a consequence of the $\mathrm{large}\text{\ensuremath{-}}{N}_{c}$ spin-flavor symmetry of QCD baryons. The predictions of $\mathrm{large}\text{\ensuremath{-}}{N}_{c}$ baryon chiral perturbation theory are in very good agreement both with the expectations from the $1/{N}_{c}$ expansion and with the experimental data.