Comparison of two K-matrix pole structures of the Pcc̅ (4312)+ pentaquark

Abstract

We present and implement two-channel K-matrix parametrization models for describing the nature of the observed P_cc̅ (4312)⁺ pentaquark in the Λ_b⁰ → J/ψ K⁻p$ decay. In this two-channel analysis, the K-matrix approach was done in order to reproduce the scattering data of the J/ψp invariant mass distribution while taking into account possible near-threshold phenomena imposed by Σ_c⁺D̅⁰ channel. The inclusion of non-resonant terms yields an ambiguous three-pole structure where one pole manifests at each unphysical complex energy E Riemann sheet. The results agree with recent studies that implemented a model-independent framework in determining the pole structure of the same pentaquark. The obtained fit and pole parameters provides an argument to support a hybrid interpretation of a compact state possibly contaminated by a pole in the [tb] sheet.