Measurement of the Decays $\Lambda_c\to \Sigma\pi\pi$ at Belle

TL;DR

This paper measures the relative branching fractions of specific $\Lambda_c^+$ decays to $\Sigma\pi\pi$ final states using Belle data, providing precise experimental results for these decay modes.

Contribution

First measurement of these $\Lambda_c^+$ decay branching fractions relative to the $pK^-\pi^+$ mode using the full Belle dataset.

Findings

Branching ratio for $\Lambda_c^+ o\Sigma^+\pi^-\pi^+$ is 0.706

Branching ratio for $\Lambda_c^+ o\Sigma^0\pi^+\pi^0$ is 0.491

Branching ratio for $\Lambda_c^+ o\Sigma^+\pi^0\pi^0$ is 0.198

Abstract

We report measurements of the branching fractions of the decays $\Lambda^+_c\to\Sigma^+\pi^-\pi^+$, $\Lambda^+_c\to\Sigma^0\pi^+\pi^0$ and $\Lambda^+_c\to\Sigma^+\pi^0\pi^0$ relative to the reference channel $\Lambda^+_c\to pK^-\pi^+$. The analysis is based on the full data sample collected at and close to $\Upsilon(4S)$ resonance by the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider corresponding to the integrated luminosity of 711 fb$^{-1}$. We measure ${\cal B}(\Lambda^+_c\rightarrow\Sigma^+\pi^-\pi^+)/{\cal B}(\Lambda^+_c\to pK^-\pi^+) = 0.706~\pm 0.003~\pm 0.029$, ${\cal B}(\Lambda^+_c\rightarrow\Sigma^0\pi^+\pi^0)/{\cal B}(\Lambda^+_c\to pK^-\pi^+) = 0.491~\pm 0.005~\pm 0.028$ and ${\cal B}(\Lambda^+_c\rightarrow\Sigma^+\pi^0\pi^0)/{\cal B}(\Lambda^+_c\to pK^-\pi^+) = 0.198~\pm 0.006~\pm 0.016$. The listed uncertainties are statistical and systematic, respectively.