Quark-model search for compact c c ¯ u d s pentaquark states

A potential quark model is used to search for a P c c ¯ s 0 = ( c c ¯ u d s ) 0 , J P = 1 / 2 − pentaquark state that has recently been observed experimentally by LHCb Collaboration at 4338.2 MeV, with a width of 7.0 MeV and high statistical significance > 15 σ . Our model Hamiltonian reproduces the masses of the low-lying charmed and strange hadrons. We use the Gaussian expansion method to solve the five-body Schrödinger equation. Employing the real scaling method, including the relevant meson-baryon thresholds explicitly, sharp resonances are distinguished from the meson-baryon scattering states. We incorporate new color states of the color-octet meson and baryon configurations as well as the color-singlet configurations for the five-quark states. We find no J P = 1 / 2 − resonance close to the observed state, and also none in the J P = 3 / 2 − state. This increases the likelihood that P c c ¯ s 0 is a Ξ c D ¯ hadronic molecule rather than a compact state.