Search for the rare decay of charmed baryon Λc+ into the pμ+μ- final state

A search for the nonresonant Λc+→pμ+μ- decay is performed using proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the LHCb experiment, corresponding to an integrated luminosity of 5.4 fb-1. No evidence for the decay is found in the dimuon invariant-mass regions where the expected contributions of resonances is subdominant. The upper limit on the branching fraction of the Λc+→pμ+μ- decay is determined to be 2.9(3.2)×10-8 at 90%(95%) confidence level. The branching fractions in the dimuon invariant-mass regions dominated by the η, ρ and ω resonances are also determined.