Search for the weak radiative decay $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3$ at BESIII

Abstract

The Cabibbo-allowed weak radiative decay $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3$ has been searched for in a sample of $\hat{I}{›}_c^{+}\bar{\hat{I}}{›}_c^{-}$ pairs produced in $e^{+}{e}^{-}$ annihilations, corresponding to an integrated luminosity of $4.5{\mathrm{fb}}^{-1}$ collected with the BESIII detector at center-of-mass energies between 4.60 and 4.70 GeV. No excess of signal above background is observed, and we set an upper limit on the branching fraction of this decay to be $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3)<4.4\times 10^{-4}$ at a confidence level of 90\%, which is in agreement with Standard Model expectations.

10 pages, 4 figures