Probing the spin parity structure of hidden charm pentaquarks from spectroscopy and magnetic moments

TL;DR

This paper analyzes the spin parity quantum numbers of hidden charm pentaquarks using a molecular model, mass spectrum calculations, and magnetic moment evaluations to better understand their structure and classification.

Contribution

It introduces a method combining the Gursey Radicati mass formula with magnetic moment calculations to assign spin parity to hidden charm pentaquarks, including strange states.

Findings

Nonstrange pentaquarks are assigned specific spin parity states.

Magnetic moments follow sum-rule relations, aiding quantum number identification.

Strange pentaquark Pcs4459 is interpreted as an SU3 flavor octet member with JP=3/2.

Abstract

We investigate the spin parity JP assignments of experimentally observed hidden charm pentaquark states within a baryon meson molecular framework. The pentaquark mass spectrum is obtained using the Gursey Radicati mass formula, with parameters fixed through a global fit to 41 experimentally established hadron masses. The resulting spectrum is then used to assign JP quantum numbers to the observed pentaquark candidates. Within this framework, the nonstrange states Pc 4312, Pc4440, and Pc 4457 are identified with the JP = 1/2, 3/2, and 5/2 configurations, respectively. The recently reported Belle state Pcs4459, which carries strangeness, is interpreted as the strange member of the SU3 flavor octet with JP = 3/2. Magnetic moments are subsequently evaluated using explicitly constructed wave functions. Their systematic behavior across SU3 flavor multiplets and different spin parity assignments satisfies the expected sum-rule relations and indicates that magnetic moments can serve as a useful observable for refining the quantum-number identification of hidden charm pentaquark states in future studies.