Symmetry Breaking and transition form factors from η and ω decays

Abstract

The WASA-at-COSY collaboration uses meson production and the decays for the realization of the physics goals. Different rare decay channels of the mesons have to be analyzed in order to investigate symmetry breaking patterns. The combination of high intensity COSY (COoler SYnchrotron) beams and the WASA 4π detector setup allows us to study the rare decay channels of light mesons. We are analyzing different symmetry breaking decay channels of η mesons. One rare decay channel η→π+π-e+e- is being used to test CP violation. The asymmetry in the angle between the electron and pion planes can give insight about the degree of CP violation. The study of another rare decay channel η→π0e+e- is a test of C-parity violation. Our analysis of transition form factors of different mesons via conversion decays (η→γγ*→e+e- γ, ω→π0e+e-) provides insight about hadron structure. The transition form-factor of the ω meson provides information about the form factor in the time-like region where the two vector particles (the ω and the intermediate virtual photon) have an invariant mass squared will be discussed. © 2013 Springer Science+Business Media Dordrecht.