A meson-baryon molecular interpretation for some (Ωc) excited states

Abstract

We explore the possibility that some of the five narrowΩcresonances recently observed at LHCbcould correspond to pentaquark states, structured as meson-baryon bound states or molecules. The inter-action of the low-lying pseudoscalar mesons with the ground-state baryons in the charm +1, strangeness−2 and isospin 0 sector is built from t-channel vector meson exchange, using effective Lagrangians. Theresulting s-wave coupled-channel unitarized amplitudes show the presence of two structures with similarmasses and widths to those of the observedΩc(3050)0andΩc(3090)0. The identification of these reso-nances with the meson-baryon bound states found in this work would also imply assigning the values 1/2−for their spin-parity. An experimental determination of the spin-parity of theΩc(3090)0would contributeto a better understanding of its structure, as the quark-based models predict its spin-parity to be either3/2−or 5/2−. Predictions for the analogue bottomΩ−bresonances are also given.