Observation of $\Lambda^+_{c}\to nK^0_S\pi^+$

TL;DR

This paper reports the first direct measurement of the decay of the $ ext{Lambda}_c^+$ baryon involving a neutron, providing a new data point for testing isospin symmetry and final state interactions.

Contribution

It presents the first direct measurement of the $ ext{Lambda}_c^+$ decay involving a neutron and determines its branching fraction using BESIII data.

Findings

Observed the decay $ ext{Lambda}_c^+ o n K_S^0 o ext{final state}$

Measured the branching fraction as approximately 1.82%

Provides data for testing isospin symmetry in charmed baryon decays

Abstract

We report the first direct measurement of decays of the $\Lambda^+_c$ baryon involving the neutron. The analysis is performed using 567 pb$^{-1}$ of $e^+e^-$ collision data collected at $\sqrt{s}=4.599$ GeV with the BESIII detector at the BEPCII collider. We observe the decay $\Lambda^+_{c}\rightarrow n K^0_S\pi^+$ and measure the absolute branching fraction to be $\mathcal{B}({\Lambda^+_{c}\rightarrow n K^0_S\pi^+})=(1.82\pm0.23({\rm stat})\pm0.11({\rm syst}))\%$. A comparison to $\mathcal{B}({\Lambda^+_{c}\rightarrow p(\bar{K}\pi)^0})$ provides an important test of isospin symmetry and final state interactions.