$\Lambda_{c}^{+}$ decays at BESIII

TL;DR

This paper reports new measurements of various decay branching fractions of the $\Lambda_{c}^{+}$ baryon using BESIII data, including the first measurement of $ pi$ decay with high significance, improving understanding of charmed baryon decays.

Contribution

First measurement of $ pi$ decay branching fraction with high significance and updated measurements of other $\Lambda_{c}^{+}$ decay modes using BESIII data.

Findings

Branching fraction of $ pi$ decay measured as $(6.6 o 1.2_{ ext{stat}} o 0.4_{ ext{syst}}) imes 10^{-4}$.

Branching fractions of $\Lambda_{c}^{+} o \Lambda \pi^{+}$ and $\Lambda_{c}^{+} o \Sigma^{0} \pi^{+}$ are consistent with previous results.

The ratio of $ pi$ to $\Lambda_{c}^{+} o p\pi^{0}$ branching fractions exceeds 7.2 at 90% CL.

Abstract

BESIII has made great progress in taking data which is the largest data samples near the $\Lambda_{c}^{+}\bar{\Lambda}_{c}^{-}$ threshold. We have measured the branching fraction of $\Lambda_{c}^{+}\to n\pi^{+}$ to be $(6.6\pm 1.2_{\mathrm{stat.}}\pm 0.4_{\mathrm{syst.}})\times 10^{-4}$ with the statistical significance of 7.3 $\sigma$ firstly using $3.9\mathrm{fb}^{-1}$ $e^{+}e^{-}$ collision collected with BESIII detector at six center-of-mass energies between 4.612 and 4.699 GeV. With the result of the branching fraction of $\Lambda_{c}^{+}\to p\pi^{0}$ from Belle, the ratio of the branching fractions between $\Lambda_{c}^{+}\to n\pi^{+}$ and $\Lambda_{c}^{+}\to p\pi^{0}$ is measured to be larger than 7.2 at 90% confidence level. The branching fractions of $\Lambda_{c}^{+}\to \Lambda \pi^{+}$ and $\Lambda_{c}^{+}\to \Sigma^{0} \pi^{+}$ are measured to be $(1.31\pm 0.08_{\mathrm{stat.}}\pm 0.05_{\mathrm{syst.}})\times 10^{-2}$ and $(1.22\pm 0.08_{\mathrm{stat.}}\pm 0.07_{\mathrm{syst.}})\times 10^{-2}$, respectively, which are consistent with previous BESIII results. More results of $\Lambda_{c}^{+}$ decays will be published with better precision this year using $6.4\mathrm{fb}^{-1}$ $e^{+}e^{-}$ collision data samples between 4.600 and 4.946 GeV.