Electromagnetic corrections in eta --> 3 pi decays
arXiv:0812.0344 · doi:10.1140/epjc/s10052-009-0863-z
Abstract
We re-evaluate the electromagnetic corrections to eta --> 3 pi decays at next-to-leading order in the chiral expansion, arguing that effects of order e^2(m_u-m_d) disregarded so far are not negligible compared to other contributions of order e^2 times a light quark mass. Despite the appearance of the Coulomb pole in eta --> pi+ pi- pi0 and cusps in eta --> 3 pi0, the overall corrections remain small.
21 pages, 11 figures; references updated, version published in EPJC