Search for the hyperon semileptonic decay $Xi^{-} rightarrow Xi^{0} e^{-} bar{ u_{e}}$


Abstract in English

Using $(10.087pm0.044)times10^{9}$ $J/psi$ events collected by the BESIII detector at the BEPCII collider, we search for the hyperon semileptonic decay $Xi^{-} rightarrow Xi^{0} e^{-} bar{ u}_{e}$. No significant signal is observed and the upper limit on the branching fraction $mathcal B(Xi^{-} rightarrow Xi^{0} e^{-} bar{ u}_{e})$ is set to be $2.59times10^{-4}$ at 90 % confidence level. This result is one order of magnitude more strict than the previous best limit.

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