Speaker
Description
The considerable amount of data on three-body decays of mesons which has
become available in recent years has revived interest in the dispersive
formalism of Khuri and Treiman as a powerful analysis tool. We consider here
the isospin breaking eta -> 3 pi amplitude which is specific in that both the
low-energy chiral expansion and dispersion relation techiques can be
applied. We reconsider an approach in which both methods are combined such as
to produce a unique, parameter-free (except for an overall factor) amplitude
in the physical region. We develop an extension of the KT formalism which
includes both eta-pi rescattering as well as inelastic rescattering to
KKbar. We compare the predicted amplitude with the recent high-precision
experimental results from KLOE, BESIII and WASA. Consequences for the isospin
breaking quark mass ratio are presented.
