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

Abstract

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.

Comments: 8 pages, 7 figures