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.
Categories: hep-ex