Theoretical study ofΛresonances from an analysis of Crystal BallK−p→π0Σ0reaction data with center-of-mass energies of 1536–1676 MeV

Abstract

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