Search for the semi-muonic charmonium decay $J/\ddot{I}ˆ\to D^{-}\hat{I}{¼}^{+}\hat{I}{½}_{\hat{I}}¼+c.c.$

Abstract

Using $(10087\pm 44)\times 10^6$ $J/\ddot{I}ˆ$ events collected with the BESIII detector at the BEPCII $e^{+}{e}^{-}$ storage ring at the center-of-mass energy of $\sqrt{s}=3.097\mathrm{GeV}$, we present a search for the rare semi-muonic charmonium decay $J/\ddot{I}ˆ\to D^{-}\hat{I}{¼}^{+}\hat{I}{½}_{\hat{I}}¼+c.c.$. Since no significant signal is observed, we set an upper limit of the branching fraction to be $\mathcal{B}(J/\ddot{I}ˆ\to D^{-}\hat{I}{¼}^{+}\hat{I}{½}_{\hat{I}}¼+c.c.)<5.6\times 10^{-7}$ at $90\%$ confidence level. This is the first search for the weak decay of charmonium with a muon in the final state.

19 pages, 5 figures