Evidence for a new Σ* resonance with JP=1/2- in the old data of the K-p→Λπ+π- reaction

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(-) Sigma(*) resonance to be above 1600 MeV, the unquenched quark models predict it to be around Sigma(*)(1385) energy. Here we reexamine some old data of the K(-)p ->Lambda pi(+)pi(-) reaction and find that besides the well-established Sigma(*)(1385) with J(P)=3/2(+), there is indeed some evidence for the possible existence of a new Sigma(*) 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.