Double-strangeness hidden-charm pentaquarks

초록

We investigate the possible existence of double-strangeness hidden-charm pentaquark states, denoted as Pcc<overline>ss, within an off-shell coupled-channel formalism. Eleven meson-baryon channels with total strangeness S = -2 are constructed by combining charmed mesons and singly charmed baryons. The two-body scattering amplitudes are derived from an effective Lagrangian that respects heavy-quark spin symmetry, hidden local symmetry, and flavor SU(3) symmetry. The Bethe-Salpeter equation is solved using the Blankenbecler-Sugar reduction scheme, and resonances are identified as poles in the scattering amplitudes on the complex energy plane. We find five negative-parity Pcc<overline>ss states with spins J = 1/2, 3/2, and 5/2, all located below their relevant thresholds. Three positive-parity states are also found: two with J = 1/2 and one with J = 3/2, lying above the thresholds with substantial widths. The coupling strengths of each resonance to relevant meson-baryon channels are extracted. The sensitivity of the results to the cutoff parameter A0 = A - m is examined. These results provide theoretical predictions that may assist future experimental searches for Pcc<overline>ss states in the J/p channel.

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