Decay and production properties of strange double charm pentaquark

In this work we investigate the decay and production properties of the strange double-charm pentaquark $P_{ccs}^{++}$ with strangeness $S=-1$. Building upon our previous work predicting its $J^P=1/2^-$ molecular configuration, we employ three-point QCD sum rules to calculate its strong decay widths and estimate its production branching ratio via $Ξ_{bc}^+$ baryon decays. The total strong decay width to the $Ξ_{cc}\bar{K}$ and $Ω_{cc}π$ final-state channels is determined as $85\pm19$ MeV. Furthermore, using a rescattering mechanism, we analyze the $Ξ_{bc}^+\rightarrow D_s^{\ast-}Ξ_{cc}^{++}\rightarrow D^-P_{ccs}^{++}$ process and estimate the production branching ratio to be $\mathcal{B}r(Ξ_{bc}^+\rightarrow D^-P_{ccs}^{++})=(4.3_{-1.5}^{+2.0})\times10^{-6}$. The relatively narrow width and detectable branching ratio suggest the possibility searching for this pentaquark state in the future.

💡 Research Summary

The paper investigates both the decay and production mechanisms of the strange double‑charm pentaquark P_ccs^{++} (strangeness S = ‑1) that was previously predicted to have quantum numbers J^P = 1/2⁻ and a molecular configuration dominated by the Ξ_cc \bar K channel. Using three‑point QCD sum rules, the authors construct interpolating currents for the pentaquark, the double‑charm baryons Ξ_cc and Ω_cc, and the light mesons \bar K and π. After performing the operator‑product expansion up to dimension‑nine condensates and applying a Borel transform, they extract the strong coupling constants g_{Pccs Ξ_cc \bar K}=‑0.45 ± 0.05 GeV⁻³ and g_{Pccs Ω_cc π}=‑0.19^{+0.05}{‑0.06} GeV⁻³. These couplings lead to partial decay widths Γ(P_ccs^{++} → Ξ_cc \bar K)=65 ± 16 MeV and Γ(P_ccs^{++} → Ω_cc π)=20^{+11}{‑10} MeV, giving a total strong width of 85 ± 19 MeV, which is relatively narrow for a state lying just above the Ξ_cc \bar K threshold.

For production, the authors consider the Cabibbo‑favored weak decay of the doubly‑heavy baryon Ξ_bc^{+}. The process proceeds via a rescattering mechanism: Ξ_bc^{+} → D_s^{‑} Ξ_cc^{++} followed by D_s^{‑} Ξ_cc^{++} → D⁻ P_ccs^{++} through \bar K⁰ exchange. The weak transition amplitude is treated in the factorization approach, involving the Fermi constant, CKM elements V_cb and V_cs, an effective Wilson coefficient a₁, and form factors f₁, f₂, g₁, g₂ taken from previous calculations. These form factors are parametrized by a dipole‑like function with parameters (F(0), m_fit, δ). Combining the weak amplitude with the strong vertex derived from the QCD sum‑rule coupling, the authors compute the branching ratio for Ξ_bc^{+} → D⁻ P_ccs^{++} as (4.3^{+2.0}_{‑1.5}) × 10⁻⁶. This magnitude is within the sensitivity reach of current experiments such as LHCb and Belle II.

The paper also attempts to study compact‑pentaquark interpolating currents with the same quark content, but the three‑point sum‑rule analysis fails to produce a stable Borel window, preventing reliable extraction of the corresponding couplings. Consequently, the molecular picture remains the only quantitatively supported configuration in this work.

In summary, the study predicts that the strange double‑charm pentaquark P_ccs^{++} should appear as a relatively narrow resonance (≈85 MeV width) and could be produced in Ξ_bc^{+} decays with a branching fraction of order 10⁻⁶. These findings provide concrete targets for experimental searches and suggest that future data from LHCb or Belle II could confirm the existence of this exotic state.