Search for the weak decays $J/\ensuremath{\psi}\ensuremath{\rightarrow}{D}_{s}^{(\mathbf{*})\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}+\mathrm{c}.\mathrm{c}.$

Search for the weak decays $J / ψ \to D_{s}^{(*) -} e^{+} ν_{e} + c . c .$

M. Ablikim et al. (BESIII Collaboration)

Phys. Rev. D 90, 112014 – Published 23 December 2014

Abstract

Using a sample of $2.25 \times 1 0^{8}$ $J / ψ$ events collected with the BESIII detector at the BEPCII collider, we search for the $J / ψ$ semileptonic weak decay $J / ψ \to D_{s}^{-} e^{+} ν_{e} + c . c .$ with a much higher sensitivity than previous searches. We also perform the first search for $J / ψ \to D_{s}^{* -} e^{+} ν_{e} + c . c .$ No significant excess of a signal above background is observed in either channel. At the 90% confidence level, the upper limits are determined to be $B (J / ψ \to D_{s}^{-} e^{+} ν_{e} + c . c .) < 1.3 \times 1 0^{- 6}$ and $B (J / ψ \to {D_{s}^{*}}^{-} e^{+} ν_{e} + c . c .) < 1.8 \times 1 0^{- 6}$ , respectively. Both are consistent with Standard Model predictions.