# Measurement of the absolute branching fractions of $\Lambda_{c}^{+}\to\Lambda\eta\pi^{+}$ and $\Sigma(1385)^{+}\eta$

## TL;DR

This paper reports precise measurements of the absolute branching fractions for the decays of the b1_c^+ baryon into b1 b5 b7^+ and b1 b5 b7^+ b5, using data from electron-positron collisions at 4.6 GeV.

## Contribution

First precise measurement of these specific b1_c^+ decay branching fractions using BESIII data at 4.6 GeV.

## Key findings

- b1_c^+ b1 b5 b7^+ branching fraction: (1.84 b1 0.21 b1 0.15)%
- b1_c^+ b1 b5 b7^+ b5 branching fraction: (0.91 b1 0.18 b1 0.09)%
- Most precise measurements to date

## Abstract

We study the decays $\Lambda_{c}^{+}\to\Lambda\eta\pi^{+}$ and $\Sigma(1385)^{+}\eta$ based on $\Lambda_{c}^{+}\bar{\Lambda}_{c}^{-}$ pairs produced in $e^+e^-$ collisions at a center-of-mass energy of $\sqrt{s}=4.6~\mbox{GeV}$, corresponding to an integrated luminosity of $567\;\mbox{pb$^{-1}$}$. The data sample was accumulated with the BESIII detector at the BEPCII collider. The branching fractions are measured to be $\mathcal{B}(\Lambda_{c}^{+} \to \Lambda\eta\pi^{+})=(1.84\pm0.21({\rm{stat.}})\pm0.15({\rm{syst.}}))\%$ and $\mathcal{B}(\Lambda_{c}^{+} \to \Sigma(1385)^{+}\eta)=(0.91\pm0.18({\rm{stat.}})\pm0.09({\rm{syst.}}))\%$, constituting the most precise measurements to date.