Delta --> N gamma in Large-Nc QCD

The decay Delta^+ --> p gamma is studied in the 1/N_c expansion of QCD. The ratio of the helicity amplitudes is determined to be A_{3/2}/A_{1/2} = \sqrt{3}

• O(1/N_c^2). Equivalently, the ratio E2/M1 of the multipole amplitudes is predicted to be order 1/N_c^2.