Evidence for a new $\hat{I}{\pounds }^{\ast }$ resonance with $J^P=1/2^{-}$ in the old data of $K^{-}p\to \hat{I}›\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ reaction

Abstract

Distinctive patterns are predicted by quenched quark models and unquenched quark models for the lowest SU(3) baryon nonet with spin parity $J^P=1/2^{-}$. While the quenched quark models predict the lowest $1/2^{-}$ $\hat{I}{\pounds }^{\ast }$ resonance to be above 1600 MeV, the unquenched quark models predict it to be around $\hat{I}{\pounds }^{\ast }(1385)$ energy. Here we re-examine some old data of the $\kp \to \la$ reaction and find that besides the well established $\hat{I}{\pounds }^{\ast }(1385)$ with $J^P=3/2^{+}$, there is indeed some evidence for the possible existence of a new $\hat{I}{\pounds }^{\ast }$ resonance with $J^P=1/2^{-}$ around the same mass but with broader decay width. Higher statistic data on relevant reactions are needed to clarify the situation.

7 pages, 4 figures