Search for η → e+e− decay with the WASA experiment

• Main Author: Berłowski M.
• Format: Article
• Language: English
• Published: EDP Sciences 2012-12-01
• Series: EPJ Web of Conferences
• Online Access: http://dx.doi.org/10.1051/epjconf/20123709007

Nowadays the field of searching for a new physics became a very interesting subject in a light meson decays due to a recent results from KTeV collaboration which found the 3.3σ disagreement between Standard Model theory and their results of π◦ → e+e− branching ratio measurement [1]. They propose to explain this discrepancy with a new U boson particle that interacts both with meson and virtual photon producing e+e −pair [2]. The same effect could be observed in eta meson decay into electron-positron. The current branching ratio limit [3,4] is far away from the predicted non-Standard Model theory and due to that fact it cannot distinguish between Standard Model and more exotic explanation. The following report shows the analysis highlights for searching for a such effect in pp → pp(η → e+e−) at 1.4 GeV produced in WASA@COSY experiment.