Study of Hidden-Charm and Hidden-Bottom Pentaquark Resonances in the Quark Model

Abstract

Inspired by the LHCb observation of hidden-charm pentaquarks, i.e., Pc(4312), Pc(4440), and Pc(4457) in the J/ψp invariant mass spectrum, a calculation of the J/ψp scattering cross-section was performed using the quark-delocalization color screening model. The results show that Pc(4312) can be identified as a hidden-charm molecular state ΣcD with JP=12−. The two-peak structure can be reproduced around 4450 MeV, which corresponds to Pc(4440) and Pc(4457). They are the resonances molecular states ΣcD* of JP=12− and JP=32−. Moreover, the Σc*D* of both JP=12− and JP=32− are possible molecular pentaquarks. Moreover, in the same theoretical frame, the calculation is extended to the Pc-like molecular pentaquarks, denoted as Pb. Several hidden-bottom pentaquarks with masses above 11 GeV and narrow widths were obtained. All of these heavy pentaquarks are worth exploring in future experiments.

Keywords

• hidden-charm pentaquark
• hidden-bottom pentaquark
• scattering cross-section
• quark model