First Observation of Doubly Cabibbo-Suppressed Decay of a Charmed Baryon: $\Lambda^{+}_{c} \rightarrow p K^{+} \pi^{-}$

TL;DR

This paper reports the first observation of a doubly Cabibbo-suppressed decay of a charmed baryon, specifically the decay of Lambda_c+ to p K+ pi-, with a measured branching ratio relative to its favored decay.

Contribution

The study provides the first experimental evidence of a doubly Cabibbo-suppressed decay in a charmed baryon, expanding understanding of charm quark decay processes.

Findings

First observation of the decay $ ext{Lambda}_c^+ ightarrow p K^+ \pi^-$.

Measured branching ratio relative to the favored decay: (2.35 ± 0.27 ± 0.21)×10^{-3}.

Data sample of 980 fb^{-1} collected by the Belle detector.

Abstract

We report the first observation of the decay $\Lambda^{+}_{c} \rightarrow p K^{+} \pi^{-}$ using a 980 $\mathrm{fb^{-1}}$ data sample collected by the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. This is the first doubly Cabibbo-suppressed decay of a charmed baryon to be observed. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be $\mathcal{B}(\Lambda^{+}_{c} \rightarrow p K^{+} \pi^{-})/\mathcal{B}(\Lambda^{+}_{c} \rightarrow p K^{-} \pi^{+})=(2.35\pm0.27\pm0.21)\times10^{-3}$, where the uncertainties are statistical and systematic, respectively.