G. Knochlein et al., RARE DECAY ETA-]PI-PI-GAMMA-GAMMA IN CHIRAL PERTURBATION-THEORY, Physical review. D. Particles and fields, 53(7), 1996, pp. 3634-3642
We investigate the rare radiative eta decay modes eta-->pi(+)pi(-) pi(
-)gamma gamma and eta-->pi(0) pi(0) gamma gamma within the framework o
f chiral perturbation theory at O(p(4)). We present photon spectra and
partial decay rates for both processes as well as a Dalitz contour pl
ot for the charged decay.