Evidence for a new resonance σ* (1380) with JP = 1/2−

A new particle σ* with JP = 1/2− was predicted by unquenched quark models with its mass around the well established σ* (1385) with JP = 3/2+. Here we re-examine some old data of the K− p → Λπ−π+ reaction. Firstly we re-fit the data for kaon beam momenta in the range of 1.0–1.8 GeV. Secondly we study the reaction at the energies around Λ* (1520) peak. Both studies show evidence for the existence of σ* with JP = 1/2− around 1380 MeV. Higher statistic data on relevant reactions are needed to clarify the situation.