Construction of the eta->3pi (and K->3pi) amplitudes using dispersive approach

Abstract

The dispersive approach based only on very general principles, unitarity, analyticity and crossing symmetry, combined with chiral counting enables to construct fully relativistic model-independent representations of the eta and K three-pion decays valid up to and including two-loop corrections. Here we demonstrate the procedure on the eta->3pi^0 decay. We perform possible matchings of our dispersive approach with the two-loop ChPT result and briefly discuss corresponding predictions of the Dalitz plot slope parameter alpha.

To appear in the proceedings of "6th International Workshop on Chiral Dynamics", CD09, July 2009, Bern, Switzerland. 6 pages. PoS style