S- and p-wave structure of S=-1 meson-baryon scattering in the resonance region

We perform a simultaneous analysis of s- and p-waves of the $S=-1$ meson-baryon scattering amplitude using all low-energy experimental data. For the first time, differential cross section data are included for chiral unitary coupled-channel models. From this model s- and p-wave amplitudes are extracted and we observe both well-known $I(J^P)=0(1/2^-)$ s-wave states as well as a new $I(J^P)=1(1/2^+)$ state absent in quark models and lattice QCD results. Multiple statistical and phenomenological tests suggest that, while the data clearly require an $I=1$ p-wave resonance, the new state just accounts for the absence of the decuplet $\Sigma(1385)3/2^+$ in the model.