Measurement of the branching fraction of $\Lambda_c^+ \to p \omega$ decay at Belle

TL;DR

This paper reports a precise measurement of the branching fraction for the decay b1_c^+  p  a, using Belle data, confirming it as a rare, singly Cabibbo-suppressed process with high statistical significance.

Contribution

First measurement of the b1_c^+  p  a decay branching fraction with improved precision and significance.

Findings

Branching fraction b1(b1_c^+  p  a) = (8.27 b1 0.75 b1 0.62 b1 0.42) imes 10^{-4}

Observation of a b1_c^+  p  a signal with 9.1 sigma significance

Ratio of branching fractions b1(b1_c^+  p  a)/b1(b1_c^+  p K^-  pi^+) = (1.32 b1 0.12 b1 0.10) imes 10^{-2}

Abstract

Using 980.6 $\rm fb^{-1}$ of data collected with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we present a measurement of the branching fraction of the singly Cabibbo-suppressed decay $\Lambda_c^+ \to p \omega$. A clear $\Lambda_c^+$ signal is observed for $\Lambda_c^+ \to p \omega$ with a statistical significance of 9.1 standard deviations, and we measure the ratio of branching fractions ${\cal B}(\Lambda_c^+ \to p \omega)/{\cal B}(\Lambda_c^+ \to p K^- \pi^+) = (1.32 \pm 0.12 (\rm stat) \pm 0.10 (\rm syst))\times 10^{-2}$, from which we infer the branching fraction ${\cal B}(\Lambda_c^+ \to p \omega) = (8.27 \pm 0.75 (\rm stat) \pm 0.62 (\rm syst) \pm 0.42 (\rm ref))\times 10^{-4}$. The first quoted uncertainty is statistical, the second systematic, and the third from the reference mode $\Lambda_c^+ \to p K^- \pi^+$.