Search for the weak decay $\psi(3686) \to \Lambda_c^{+} \bar{\Sigma}^- +c.c$

TL;DR

This paper reports the first search for the weak decay of $\psi(3686)$ into $\Lambda_c^{+}$ and $ar{\Sigma}^-$, using a large dataset, but finds no significant signal and sets an upper limit on the branching fraction.

Contribution

It introduces the first search for this specific weak decay mode of $\psi(3686)$ and establishes an upper limit on its branching fraction.

Findings

No significant signal observed.

Upper limit on branching fraction set at 1.4×10⁻⁵.

Analysis used a blinded method with a large dataset.

Abstract

Using $(448.1 \pm 2.9) \times 10^{6}$ $\psi(3686)$ events collected with the BESIII detector, we perform the first search for the weak baryonic decay $\psi(3686) \to \Lambda_c^{+} \bar{\Sigma}^- +c.c.$. The analysis procedure is optimized using a blinded method. No significant signal is observed, and the upper limit on the branching fraction ($\mathcal B$) of $\psi(3686) \to \Lambda_c^{+} \bar{\Sigma}^- +c.c.$ is set to be $1.4\times 10^{-5}$ at the 90\% confidence level.