Header menu link for other important links
X
Measurement of the branching fraction of and search for a CP -violating asymmetry in η′ →π+π-e+e- At BESIII
M. Ablikim, M.N. Achasov, P. Adlarson, S. Ahmed, M. Albrecht, A. Amoroso, Q. An, X.H. Bai, Y. Bai, O. BakinaShow More
Published in American Physical Society
2021
Volume: 103
   
Issue: 9
Abstract
The rare decay η′→π+π-e+e- is studied using a sample of 1.3×109 J/ψ events collected with the BESIII detector at BEPCII in 2009 and 2012. The branching fraction is measured with improved precision to be (2.42±0.05stat±0.08syst)×10-3. Due to the inclusion of new data, this result supersedes the last BESIII result on this branching fraction. In addition, the CP-violating asymmetry in the angle between the decay planes of the π+π - pair and the e+e - pair is investigated. A measurable value would indicate physics beyond the standard model; the result is ACP=(2.9±3.7stat±1.1syst)%, which is consistent with the standard model expectation of no CP-violation. The precision is comparable to the asymmetry measurement in the KL0→π+π-e+e- decay where the observed (14±2)% effect is driven by a standard model mechanism. © 2021 authors. Published by the American Physical Society.
About the journal
JournalData powered by TypesetPhysical Review D
PublisherData powered by TypesetAmerican Physical Society
ISSN24700010