Search for the rare decay of charmed baryon $\Lambda_c^+$ into $p \mu^+ \mu^-$ final state

TL;DR

This paper reports a search for the rare nonresonant decay of the charmed baryon Lambda_c+ into a proton and two muons, setting upper limits on its branching fraction using LHCb data.

Contribution

First search for the nonresonant Lambda_c+ to p mu+ mu- decay, establishing upper limits on its branching fraction with proton-proton collision data at 13 TeV.

Findings

No evidence for the decay was observed.

Upper limit on the branching fraction is 2.9 x 10^-8 at 90% CL.

Branching fractions in resonance regions were also measured.

Abstract

A search for the nonresonant $\Lambda_c^+ \to p \mu^+ \mu^-$ decay is performed using proton-proton collision data recorded at a centre-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 $\Lambda_c^+ \to p \mu^+ \mu^-$ decay is determined to be $2.9~(3.2) \times 10^{-8}$ at 90% (95%) confidence level. The branching fractions in the dimuon invariant-mass regions dominated by the $\eta$, $\rho$ and $\omega$ resonances are also determined.