η→π^(0)γ γ decay within a chiral unitary approach revisited

Abstract

In view of the recent experimental developments in η→π^(0)γ γ decay, and the fact that the Particle Data Group in the online edition of 2007 reports sizable changes of the radiative decay widths of vector mesons used as input in the theoretical calculations of E. Oset, J. R. Peláez, and L. Roca [Phys. Rev. D 67, 073013 (2003)], a reevaluation of the decay width of the in this channel has been done, reducing its uncertainty by almost a factor of 2. The new input of the Particle Data Group is used, and invariant mass distributions and total widths are compared with the most recent results from the AGS and MAMI experiments, and preliminary ones of KLOE. The agreement of the theory with the AGS and MAMI data is very good, both for the total rates and for the invariant mass distributions of the two photons.