2023/12/04 by Satoshi Nakamura, Jia-Jun Wu, Nakamura, Satoshi X. +1
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2312.01989
openalex publication_date 2023/12/04 · openalex created_date 2023/12/06 · openalex updated_date 2026/07/28
Recent LHCb data for B-→ J/ψΛp show a clear peak structure at the ΞcD threshold in the J/ψΛ invariant mass (MJ/ψΛ) distribution. The LHCb's amplitude analysis identified the peak with the first hidden-charm pentaquark with strangeness PψsΛ(4338). We conduct a coupled-channel amplitude analysis of the LHCb data by simultaneously fitting the MJ/ψΛ, M_J/ψp, M_Λp, and cosθK^* distributions. Rather than the Breit-Wigner fit employed in the LHCb analysis, we consider relevant threshold effects and a unitary ΞcD-ΛcDs coupled-channel scattering amplitude from which PψsΛ poles are extracted for the first time. In our default fit, the PψsΛ(4338) pole is almost a Ξc D bound state at ( 4338.2± 1.4)-( 1.9± 0.5 ) i MeV. Our default model also fits a large fluctuation at the ΛcDs threshold, giving a ΛcDs virtual state, PψsΛ(4255), at 4254.7± 0.4 MeV. We also found that the PψsΛ(4338) peak cannot solely be a kinematical effect, and a nearby pole is needed.