Eur. Phys. J. A (2004) 19: 367-382
https://doi.org/10.1140/epja/i2003-10140-1Two-photon decays of
https://doi.org/10.1140/epja/i2003-10140-1
Two-photon decays of 
, 
and 
Physik Department, Technische Universität München, D-85747, Garching, Germany
* e-mail: borasoy@ph.tum.de
We investigate the decays of 
and into two photons in an effective U(3) chiral Lagrangian approach without employing large-
arguments. Tree level and one-loop contributions from the anomalous Wess-Zumino-Witten Lagrangian are calculated and the importance of - mixing is discussed. Unitarity corrections beyond one loop play an important role for the decays with off-shell photons and are included by employing a coupled-channel Bethe-Salpeter equation which satisfies unitarity constraints and generates vector mesons from composed states of two pseudoscalar mesons.
© Società Italiana di Fisica and Springer-Verlag, 2004
