We report the first observation of two charmed strange baryons that decay into ${\ensuremath{\Lambda}}_{c}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$. The broader of the two states is measured to have a mass of $2978.5\ifmmode\pm\else\textpm\fi{}2.1\ifmmode\pm\else\textpm\fi{}2.0\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and a width of $43.5\ifmmode\pm\else\textpm\fi{}7.5\ifmmode\pm\else\textpm\fi{}7.0\text{ }\text{ }\mathrm{MeV}/{c}^{2}$. The mass and width of the narrow state are measured to be $3076.7\ifmmode\pm\else\textpm\fi{}0.9\ifmmode\pm\else\textpm\fi{}0.5\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and $6.2\ifmmode\pm\else\textpm\fi{}1.2\ifmmode\pm\else\textpm\fi{}0.8\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, respectively. We also perform a search for the isospin partner states that decay into ${\ensuremath{\Lambda}}_{c}^{+}{K}_{S}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}$ and observe a significant signal at the mass of $3082.8\ifmmode\pm\else\textpm\fi{}1.8\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }\mathrm{MeV}/{c}^{2}$. The data used for this analysis were accumulated at or near the $\ensuremath{\Upsilon}(4S)$ resonance, using the Belle detector at the ${e}^{+}{e}^{\ensuremath{-}}$ asymmetric-energy collider KEKB. The integrated luminosity of the data sample used is $461.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$.
Observation of New States Decaying intoΛc+K−π+andΛc+KS0π− | Litlas
