Measurement of the absolute branching fraction of the inclusive decay $\Lambda_c^+ \to K_S^0X$

TL;DR

This paper reports the first measurement of the absolute branching fraction of the inclusive decay mbda_c^+  K_S^0 X using electron-positron collision data, revealing potential unobserved decay modes.

Contribution

It provides the first measurement of the absolute branching fraction for mbda_c^+  K_S^0 X using the double-tag technique at .6 GeV.

Findings

Branching fraction measured as (9.9 b1 0.6 b1 0.4)%

Relative deviation suggests existence of unobserved decay modes

Analysis performed with 567 pb^{-1} data at BESIII

Abstract

We report the first measurement of the absolute branching fraction of the inclusive decay $\Lambda_c^+ \to K_S^0X$. The analysis is performed using an $e^+e^-$ collision data sample corresponding to an integrated luminosity of 567 pb$^{-1}$ taken at $\sqrt{s}$ = 4.6 GeV with the BESIII detector. Using eleven Cabibbo-favored $\bar{\Lambda}_c^-$ decay modes and the double-tag technique, this absolute branching fraction is measured to be $\mathcal{B}(\Lambda_c^+ \to K_S^0X)=(9.9\pm0.6\pm0.4)\%$, where the first uncertainty is statistical and the second systematic. The relative deviation between the branching fractions for the inclusive decay and the observed exclusive decays is $(18.7\pm8.3)\%$, which indicates that there may be some unobserved decay modes with a neutron or excited baryons in the final state.