Speaker
Zhijun Li
(Sun Yat-Sen University)
Description
Charmonium weak decay is allowed in the Standard Model but has never been observed. Using (10087±44)×106 𝐽/𝜓 events collected with the BESIII detector at the BEPCII 𝑒+𝑒− storage ring at the center-of-mass energy of √𝑠=3.097 GeV, we present a search for the charmonium rare semi-muonic decay 𝐽/𝜓→𝐷−𝜇+𝜈𝜇 and its charge conjugation (c.c.) mode. Since no significant signal above the background is observed, we set an upper limit of the branching fraction to be BF(𝐽/𝜓→𝐷−𝜇+𝜈𝜇+𝑐.𝑐.)<5.6×10−7 at a confidence level of 90%. This is the first search for the weak decay of charmonium with a muon in the final state and the measurement is compatible with the SM theoretical predictions.
Primary author
Zhijun Li
(Sun Yat-Sen University)
