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

Author:

Montana, Gloria  Feijoo, Albert  Ramos, Angels  

Journal:

EUROPEAN PHYSICAL JOURNAL A

Issue Date:

2018

Abstract(summary):

We explore the possibility that some of the five narrow Omega(c) resonances recently observed at LHCb could correspond to pentaquark states, structured as meson-baryon bound states or molecules. The interaction 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. The resulting s-wave coupled-channel unitarized amplitudes show the presence of two structures with similar masses and widths to those of the observed Omega(c)(3050)(0) and Omega(c)(3090)(0). The identification of these resonances 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 the Omega c(3090)(0) would contribute to a better understanding of its structure, as the quark-based models predict its spin-parity to be either 3/2(-) or 5/2(-). Predictions for the analogue bottom Omega(-)(b) resonances are also given.