Chiral-loop and vector-meson contributions to eta -> pi pi gamma gamma decays

Abstract

The process eta -> pi0 pi0 gamma gamma is discussed in Chiral Perturbation Theory (ChPT) extending two recent analyses. Special attention is devoted to one-loop corrections, eta-eta' mixing effects and vector-meson dominance of ChPT counter-terms. The less interesting eta -> pi^+ pi^- gamma gamma transition is briefly discussed too.

Comments: 15 pages, 3 Postscript figures, uses epsfig.sty