Measurement of the Decays ${\Lambda }_c\to \Sigma \pi \pi$ at Belle

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 ${\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+}$. The analysis is based on the full data sample collected at and close to ${\rm Y}(4S)$ resonance by the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider corresponding to the integrated luminosity of 711 fb${}^{-1}$. We measure $\mathcal{B}({\Lambda }_c^{+}\to {\Sigma }^{+}{\pi }^{-}{\pi }^{+})/\mathcal{B}({\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+})=0.706\pm 0.003\pm 0.029$, $\mathcal{B}({\Lambda }_c^{+}\to {\Sigma }^0{\pi }^{+}{\pi }^0)/\mathcal{B}({\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+})=0.491\pm 0.005\pm 0.028$ and $\mathcal{B}({\Lambda }_c^{+}\to {\Sigma }^{+}{\pi }^0{\pi }^0)/\mathcal{B}({\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+})=0.198\pm 0.006\pm 0.016$. The listed uncertainties are statistical and systematic, respectively.

Submitted to PRD