Observation of ψ(3686)→η′e+e−


Ablikim M., Achasov M., Ahmed S., Albrecht M., Alekseev M., Amoroso A., ...Daha Fazla

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, cilt.783, ss.452-458, 2018 (SCI-Expanded, Scopus) identifier identifier

Özet

Using a data sample of 448.1×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay ψ(3686)→η′e+e−, with significances of 7.0σ and 6.3σ when reconstructing the η′ meson via its decay modes η′→γπ+π− and η′→π+π−η (η→γγ), respectively. The weighted average branching fraction is determined to be B(ψ(3686)→η′e+e−)=(1.90±0.25±0.11)×10−6, where the first uncertainty is statistical and the second systematic.