Observation of an excited $\hat{I}{\text{c◯}}^{-}$ baryon

Abstract

Using data recorded with the Belle detector, we observe a new excited hyperon, an $\hat{I}{\text{c◯}}^{\ast -}$ candidate decaying into $\hat{I}{ž}^0{K}^{-}$ and $\hat{I}{ž}^{-}{K}_S^0$ with a mass of $2012.4\pm 0.7(\mathrm{stat})\pm 0.6(\mathrm{syst})\mathrm{MeV}/c^2$ and a width of $\hat{I}“=6.4_{-2.0}^{+2.5}(\mathrm{stat})\pm 1.6(\mathrm{syst})\mathrm{MeV}$. The $\hat{I}{\text{c◯}}^{\ast -}$ is seen primarily in $\hat{I}\yen (1S),\hat{I}\yen (2S)$, and $\hat{I}\yen (3S)$ decays.

Submitted to PRL