Search for the rare decay $Lambda_{c}^{+} to pmu^+mu^-$

A search for the flavor-changing neutral-current decay $Lambda_{c}^{+} to pmu^+mu^-$ is reported using a data set corresponding to an integrated luminosity of $3.0rm fb^{-1}$ collected by the LHCb collaboration. No significant signal is observed outside of the dimuon mass regions around the $phi$ and $omega$ resonances and an upper limit is placed on the branching fraction of $mathcal{B} (Lambda_{c}^{+} to pmu^+mu^-) < 7.7~(9.6)times 10^{-8}~{rm at}~90%~(95%)$ confidence level. A significant signal is observed in the $omega$ dimuon mass region for the first time.