Bonn 2010 – wissenschaftliches Programm
HK 54.7: Vortrag
Donnerstag, 18. März 2010, 18:30–18:45, HG V
Status of the analysis of the rare eta-meson decay η → π0 + e+ + e− with WASA-at-COSY — •Florian Bergmann, Alfons Khoukaz, Paul Goslawski, Annika Passfeld, Tobias Rausmann, and Alexander Winnemöller — Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 9, D-48149 Münster, Germany
Studies of symmetries and symmetry breaking allow for a better understanding of the physics of the strong interaction. An elegant way to investigate the violation of conservation laws, which are directly connected to symmetry breaking effects, is the study of rare meson decays. An extensive physics program on eta decays has been initiated at the WASA-at-COSY facility. High statistics η-meson production is necessary to reach new limits on the breaking of C, P and T symmetries or combinations thereof.
In this contribution the status of the analysis of the C-violating η-decay η → π0+e++e− will be presented and discussed. The dominant C-conserving contribution to this decay via the π0+γ*+γ* intermediate state has an expected branching ratio of about 10−8 in the standard model. An observation of a significantly higher branching ratio would indicate the presence of a C-violation process.
Supported by Forschungszentrum Jülich, BMBF, and Wallenberg Foundation.