Chiral divergent properties of hadrons in the large Nc limit

Abstract We compute the leading non-analytic correction to the baryon mass in the combined limits mπ → 0, Nc → ∞ with mπNc held fixed. We reproduce the results of Cohen and Broniowski using semiclassical methods rather than heavy-baryon chiral perturbation theory. The calculation is organized to demonstrate: 1 the model independence of our results; and 2 the crucial role played by (iso)rotations of the hedgehog pion cloud surrounding the baryon. Our rotationally improved large-Nc calculation yields results that naturally interpolate between ordinary chiral perturbation theory on the one hand, and large-Nc physics on the other.