On the possibility of testing the two-peak structure of the LHCb hidden-charm strange pentaquark Pcs(4459)0 in near-threshold antikaon-induced charmonium production on protons and nuclei

Abstract

Accounting for the LHCb observation that the reported hidden-charm strange pentaquark Pcs(4459)0 can split into two substructures, Pcs(4455)0 and Pcs(4468)0, with a mass difference of 13 MeV as well as the newly observed hidden-charm pentaquark resonance Pcs(4338)0 with strangeness, we study within the double-peak scenario for the Pcs(4459)0 state the near-threshold J/ψ meson production from protons and nuclei by considering incoherent direct non-resonant (K−p→J/ψΛ) and two-step resonant (K−p→Pcsi0→J/ψΛ, i=1, 2, 3; Pcs10=Pcs(4338)0, Pcs20=Pcs(4455)0, Pcs30=Pcs(4468)0) charmonium production processes with the main goal of clarifying the possibility to observe within this scenario both above two substructures contributing to the Pcs(4459)0 state and the Pcs(4338)0 resonance in this production. We calculate the absolute excitation functions, energy and momentum distributions for the non-resonant, resonant and for the combined (non-resonant plus resonant) production of J/ψ mesons on protons as well as on carbon and tungsten target nuclei at near-threshold incident antikaon beam momenta by assuming the spin-parity assignments of the hidden-charm resonances Pcs(4338)0, Pcs(4455)0 and Pcs(4468)0 as JP=(1/2)−, JP=(1/2)− and JP=(3/2)− within four different realistic choices for the branching ratios of their decays to the J/ψΛ mode (0.125, 0.25, 0.5 and 1%) as well as for two options for the branching fraction of their decays to the K−p channel (0.01 and 0.001%). We show that these combined observables reveal clear sensitivity to these scenarios. Hence, they may be an important tool to provide further evidence for the existence of the above strange hidden-charm pentaquark resonances.