Triple-strangeness hidden-charm pentaquarks

Abstract

We investigate the possible existence of triple-strangeness hidden-charm pentaquark states in the off-shell coupled-channel formalism. The open-charm meson-baryon $\bar{D}_s\Omega_c$, $\bar{D}_s\Omega_c^*$, $\bar{D}_s^*\Omega_c$, and $\bar{D}_s^*\Omega_c^*$ channels are considered, together with the hidden-charm $J/\psi\Omega$ channel. The two-body kernel Feynman amplitudes are constructed from an effective Lagrangian based on hidden local symmetry and heavy-quark spin symmetry. The coupled Blankenbecler-Sugar equation is solved in the partial-wave helicity basis. We observe two triple-strangeness hidden-charm pentaquark states: $P_{c\bar{c}sss}(4787)$ and $P_{c\bar{c}sss}(4841)$, both with $J^P=1/2^-$. The $P_{c\bar{c}sss}(4787)$ couples dominantly to the $\bar{D}_s^*\Omega_c$ and $\bar{D}_s^*\Omega_c^*$ channels, while the $P_{c\bar{c}sss}(4841)$ couples almost exclusively to the $\bar{D}_s^*\Omega_c^*$ channel. The total transition cross sections of $\bar{D}_s^{(\ast)}\Omega_c^{(\ast)}\to J/\psi\,\Omega$ indicate that the $P_{c\bar{c}sss}(4787)$ is clearly visible in the $J/\psi\,\Omega$ invariant mass spectrum, whereas the $P_{c\bar{c}sss}(4841)$ is obscured by cusp structures and background contributions.