Pcs(4459) and other possible molecular states from Ξc(*)D¯(*) and Ξc′D¯(*) interactions

Abstract

Recently, the LHCb Collaboration reported a new structure ${P}_{cs}(4459)$ with a mass of 19 MeV below the ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ threshold. It may be a candidate of molecular state from the ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ interaction. In the current work, we perform a coupled-channel study of the ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}{\overline{D}}^{*}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}$, ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}\overline{D}$, and ${\mathrm{\ensuremath{\Xi}}}_{c}\overline{D}$ interactions in the quasipotential Bethe-Salpeter equation approach. With the help of the heavy quark chiral effective Lagrangian, the potential is constructed by light meson exchanges. Two ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ molecular states are produced with spin parities ${J}^{P}=1/{2}^{\ensuremath{-}}$ and $3/{2}^{\ensuremath{-}}$. The lower state with $3/{2}^{\ensuremath{-}}$ can be related to the observed ${P}_{cs}(4450)$ while two-peak structure cannot be excluded. Within the same model, other strange hidden-charm pentaquarks are also predicted. Two states with spin parities $1/{2}^{\ensuremath{-}}$ and a state with $3/{2}^{\ensuremath{-}}$ are predicted near the ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}\overline{D}$, ${\mathrm{\ensuremath{\Xi}}}_{c}\overline{D}$, and ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}$ thresholds, respectively. As two states near ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ threshold, two states are produced with $1/{2}^{\ensuremath{-}}$ and $3/{2}^{\ensuremath{-}}$ near the ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}$ threshold. The couplings of the molecular states to the considered channels are also discussed. The experimental research of those states are helpful to understand the origin and internal structure of the ${P}_{cs}$ and ${P}_{c}$ states.