# Observation of the decay $\Lambda_c^+\rightarrow \Sigma^- \pi^+\pi^+\pi^0$

## TL;DR

This paper reports the first observation and measurement of the decay $oldsymbol{ ext{Lambda}_c^+
ightarrow ext{Sigma}^- ext{pi}^+ ext{pi}^+ ext{pi}^0}$, providing new data on charmed baryon decay modes using $e^+e^-$ collision data at BESIII.

## Contribution

The paper presents the first observation of a specific Lambda_c^+ decay mode and provides precise measurements of its branching fraction, improving understanding of charmed baryon decays.

## Key findings

- First observation of $ ext{Lambda}_c^+
ightarrow ext{Sigma}^- ext{pi}^+ ext{pi}^+ ext{pi}^0$ decay.
- Branching fraction measured as $(2.11 \pm0.33 ext{(stat.)} ext{±}0.14 ext{(syst.)}) ext{ extperthousand}$.
- Improved measurement of $ ext{Lambda}_c^+
ightarrow ext{Sigma}^- ext{pi}^+ ext{pi}^+$ decay.

## Abstract

We report the first observation of the decay $\Lambda^+_{c}\rightarrow \Sigma^- \pi^+\pi^+\pi^0$, based on data obtained in $e^+e^-$ annihilations with an integrated luminosity of 567~pb$^{-1}$ at $\sqrt{s}=4.6$~GeV. The data were collected with the BESIII detector at the BEPCII storage rings. The absolute branching fraction $\mathcal{B}(\Lambda^+_{c}\rightarrow\Sigma^-\pi^+\pi^+\pi^0)$ is determined to be $(2.11\pm0.33({\rm stat.})\pm0.14({\rm syst.}))\%$. In addition, an improved measurement of $\mathcal{B}(\Lambda^+_{c}\rightarrow\Sigma^-\pi^+\pi^+)$ is determined as $(1.81\pm0.17({\rm stat.})\pm0.09({\rm syst.}))\%$.