Triple-strangeness hidden-charm pentaquarks

TL;DR

This work addresses the potential existence of triple-strangeness hidden-charm pentaquarks $P_{c\bar{c}sss}$ by formulating an off-shell coupled-channel approach with five two-body channels, including $J/\psi\Omega$. The authors construct two-body kernels from an effective Lagrangian that respects hidden local symmetry and heavy-quark spin symmetry, and solve the three-dimensional Blankenbecler–Sugar reduction of the Bethe–Salpeter equation to search for resonance poles. They find two $J^P=1/2^-$ resonances at masses $M=4787$ MeV and $4841$ MeV with widths $\Gamma\approx 14.4$ MeV and $86.2$ MeV, respectively, where the first couples dominantly to $\bar{D}_s^*\Omega_c$ and $\bar{D}_s^*\Omega_c^*$ and the second to $\bar{D}_s^*\Omega_c^*$. Transition cross sections to $J/\psi\Omega$ indicate that the 4787 state is clearly visible in the $J/\psi\Omega$ invariant mass spectrum, while the 4841 state is obscured by cusp structures and background. These results provide predictive guidance for experimental searches and extend the landscape of hidden-charm pentaquark studies to the triple-strangeness sector.

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 $\bar{D}_sΩ_c$, $\bar{D}_sΩ_c^*$, $\bar{D}_s^*Ω_c$, and $\bar{D}_s^*Ω_c^*$ channels are considered, together with the hidden-charm $J/ψΩ$ 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 $\bar{D}_s^*Ω_c$ and $\bar{D}_s^*Ω_c^*$ channels, while the $P_{c\bar{c}sss}(4841)$ couples almost exclusively to the $\bar{D}_s^*Ω_c^*$ channel. The total transition cross sections of $\bar{D}_s^{(\ast)}Ω_c^{(\ast)}\to J/ψ\,Ω$ indicate that the $P_{c\bar{c}sss}(4787)$ is clearly visible in the $J/ψ\,Ω$ invariant mass spectrum, whereas the $P_{c\bar{c}sss}(4841)$ is obscured by cusp structures and background contributions.

Figures (6)

• Figure 1: Predicted $P_{c\bar{c}sss}$ states from the present work.
• Figure 2: Graphical representation of the coupled integral equation.
• Figure 3: $t$-channel meson-exchange diagrams. $M$ and $B$ denote a meson and a baryon involved in the process, respectively.
• Figure 4: Elastic partial-wave cross sections for $J^P=1/2^-,\,3/2^-,\, 5/2^-$ (upper left, upper right, and lower left panels) and total cross section (lower right panel) versus total energy. The subscript $i$ labels the two-particle states shown in the legend.
• Figure 5: Contour plot of the modulus squared for the $\bar{D}_s^*\Omega_c^*$ transition amplitude in the complex total energy plane. Two poles are observed, which correspond to the $P_{c\bar{c}sss}(4787)$ (upper left pole) and $P_{c\bar{c}sss}(4841)$ (lower right pole).