Measurement of η meson decays into lepton-antilepton pairs
2007 (English)Report (Other academic)
A search for rare lepton decays of the η meson was performed using the WASA detector at CELSIUS. Two candidates for double Dalitz decay η→e+e−e+e− events are reported with a background of 1.3±0.2 events. This allows to set an upper limit to the branching ratio of 9.7×10−5 η(90% CL). The branching ratio for the decay η→e+e−γ is determined to (7.8±0.5stat ±0.8syst)×10−3 in agreement with world average value. An upper limit (90% CL) for the branching ratio for the η→e+e− decay is 2.7 × 10−5 and a limit for the sum of the η→μ+μ−μ+μ− and η→π+π−μ+μ− decays is 3.6 × 10−4.
Place, publisher, year, edition, pages
2007. , 9 p.
, e-Print: arXiv, 0711.3531
IdentifiersURN: urn:nbn:se:uu:diva-85641OAI: oai:DiVA.org:uu-85639DiVA: diva2:113748