Measurement of the Absolute Branching Fraction for $\Lambda_c^+\rightarrow \Lambda \mu^+\nu_{\mu}$

TL;DR

This paper reports the first measurement of the absolute branching fraction for the decay of Lambda_c+ into Lambda mu+ nu_mu, providing new experimental data on this semileptonic decay mode.

Contribution

It presents the first experimental determination of the absolute branching fraction for Lambda_c+ to Lambda mu+ nu_mu decay using BESIII data.

Findings

Branching fraction measured as (3.49 ± 0.46 (stat) ± 0.27 (syst))%.

Ratio of muon to electron decay modes is 0.96 ± 0.16 (stat) ± 0.04 (syst).

First measurement of this decay mode's absolute branching fraction.

Abstract

We report the first measurement of the absolute branching fraction for $\Lambda^+_{c}\rightarrow \Lambda \mu^+\nu_{\mu}$. This measurement is based on a sample of $e^+e^-$ annihilation data at a center-of-mass energy of $\sqrt{s}=4.6$ GeV collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pb$^{-1}$. The branching fraction is determined to be $\mathcal B({\Lambda^+_c\rightarrow \Lambda \mu^+\nu_{\mu}})=(3.49\pm0.46({\rm stat})\pm0.27({\rm syst}))\%$. In addition, we calculate the ratio $\mathcal{B}(\Lambda^+_c\rightarrow \Lambda \mu^+\nu_{\mu})/\mathcal{B}(\Lambda^+_c\rightarrow \Lambda e^+\nu_{e})$ to be $0.96\pm0.16({\rm stat})\pm0.04({\rm syst})$.