Analysis of the Crystal Ball data on $K^{-}p\to {\pi }^0{\Sigma }^0$ reaction with center-of-mass energies of $1536\sim 1676$ MeV

Abstract

With an effective Lagrangian approach, we analyze the $K^{-}p\to {\pi }^0{\Sigma }^0$ reaction to study the $\Lambda$ hyperon resonances by fitting the Crystal Ball data on differential cross sections and ${\Sigma }^0$ polarization with the center-of-mass energies of $1536\sim 1676$ MeV. Besides well established PDG 4-star $\Lambda$ resonances around this energy range, the $\Lambda (1600){\frac{1}{2}}^{+}$ resonance, listed as a 3-star resonance in PDG, is found to be definitely needed. In addition, there is strong evidence for the existence of a new $\Lambda ({\frac{3}{2}}^{+})$ resonance around 1680 MeV.

Comments: 18 pages, 7 figures