Electromagnetic effects in η → 3π

Abstract

PoS(CD09)043 We re-evaluate the electromagnetic corrections to η → 3π decays at next-to-leading order in the chiral expansion, arguing that effects of order e2 (md − mu) disregarded so far are not negligible compared to other contributions of order e2 times a light-quark mass. Despite the appearance of the Coulomb pole in η → π0π + π − and cusps in η → 3π 0, the overall corrections remain small. 6th International Workshop on Chiral Dynamic