Molecular interpretation of the LHCb pentaquarks from an analysis of J/ψp spectrum

¹ Instituto de Física Corpuscular (centro mixto CSIC-UV), Institutos de Investigación de Paterna, Apartado 22085, 46071, Valencia, Spain
² Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn, Germany

^* e-mail: du.menglin@ific.uv.es

Published online: 11 January 2022

Abstract

A coupled-channel approach including the Λ_cD¯^(*) and ηcp channels in addition to the Σ_c^(*)D¯^(*) and J/ψp channels, as required by unitarity and heavy quark spin symmetry (HQSS), is applied to the hidden-charm pentaquark Pc states, i.e., P_c(4312), P_c(4440) and P_c(4457), discovered by LHCb Collaboration. It is demonstrated that to obtain cutoff independent results, the one-pion exchange potential in the multichannel systems is to be supplemented with next-leading order counter terms responsible for the S-wave-to-D-wave transitions. We show that the experimental data for the J/ψp mass distributions are fully in line with the Σ_cD¯ and Σ_cD¯^* hadronic molecular interpretation of the P_c(4312) and P_c(4440)/P_c(4457), respectively. A narrow Σ_c^*D¯ molecule around 4.38 GeV is required by the HQSS with the evidence for its existence seen in the J/ψp spectrum. Moreover, we predict the line shapes for the elastic and inelastic channels.