Exploring two-body strong decay properties for possible single charm molecular pentaquarks with strangeness $|S|=1,2$

Abstract

The exploration of exotic hadrons provides a crucial testing ground for quantum chromodynamics in its non-perturbative regime. In this work, we perform a systematic study of the two-body strong decay properties of single-charm molecular pentaquarks in the $Y_c\bar{K}^{(*)}$ systems, where $Y_c = Λ_c$, $Σ_c$, $Ξ_c$, and $Ξ_c'$. Employing an effective Lagrangian approach combined with hadronic molecular wave functions derived from the one-boson-exchange model, we compute the decay widths and branching ratios for a series of predicted states with strangeness $|S| = 1$ and $|S| = 2$. Our calculations reveal distinctive decay patterns that serve as fingerprints for molecular identification. The total decay widths vary dramatically, from less than 1 MeV for the narrow $Σ_c\bar{K}$ $(I(J^P)=1/2(1/2^-))$ state to several tens of MeV for broader coupled-channel molecules like $Λ_c\bar{K}^*/Σ_c\bar{K}^*$. A key finding is the stability of the predicted branching ratios against variations in the binding energy. The decay dynamics are dominated by light meson (particularly pion) exchange, leading to a strong preference for final states containing a charmed baryon and a strange meson. Furthermore, coupled-channel effects and isospin-related interference play essential roles in both the formation and decay mechanisms of specific candidates. The results provide concrete, testable predictions for future experimental searches at facilities such as LHCb and Belle II.

Figures (4)

• Figure 1: Two-body strong decay channels for $Y_c\bar{K}^{(*)}$ molecules through the $S-$wave interactions
• Figure 2: Two-body strong decay behavior for $\Lambda_c \bar{K}^{*}$ and $\Sigma_c \bar{K}^{*}$ molecules through the $S-$wave interactions, and final states with negligible branching ratios are not shown.
• Figure 3: Two-body strong decay behavior for $\Xi_c^{(\prime)} \bar{K}^{*}$ molecules through the $S-$wave interactions, and final states with negligible branching ratios are not shown.
• Figure 4: The bound state solutions (the binding energy $E$, the root-mean-square radius $r_{rms}$, and the probabilities $P$) for all the discussed channels of the coupled ${\Xi^\prime_c} \bar{K}/{\Xi_c}\bar{K}^* /{\Xi^\prime_c}\bar{K}^*$ systems with $I(J^P) = 0(1/2^-)$, ${\Xi_c}\bar{K}^* /{\Xi^\prime_c}\bar{K}^*$ systems with $I(J^P) = 0(1/2^-)$ and $0(3/2^-)$, ${\Xi^\prime_c}\bar{K}^*$ systems with $I(J^P) = 0(1/2^-)$ , $0(3/2^-)$ and $1(3/2^-)$.