Spectrum of the uudcc¯ hidden charm pentaquark with an SU(4) flavor-spin hyperfine interaction

Abstract

We study a few of the lowest states of the pentaquark uudcc¯ , of positive and negative parity, in a constituent quark model with an SU(4) flavor-spin hyperfine interaction. For positive parity we introduce space wave functions of appropriate permutation symmetry with one unit of orbital angular momentum in the internal motion of the four-quark subsystem or an orbital excitation between the antiquark and the four quark subsystem which remains in the ground state. We show that the lowest positive parity states 1 / 2 +, 3 / 2 + are provided by the first alternative and are located below the 1 / 2 - and the 1 / 2 + states with all quarks in the ground state. We compare our results with the LHCb three narrow pentaquark structures reported in 2019.