Resolving the puzzling decay patterns of charged Zc and Zb states

الأصل · EN

We investigate the ratio of the branching fractions of the molecular candidates decaying into the ground and radially excited states within the quark interchange model. Our numerical results suggest that these molecular candidates are more likely to decay into the radially excited states than into ground states. Especially, the ratio Γ[Zc(4430)→ πψ(2S)]/Γ[Zc(4430)→ πJ/ψ] 9.8 is close to the experimental measurement, which supports the interpretation of Zc(4430) as the DD*(2S) molecular state. The ratios of the branching fractions of Zb(10610) and Zb(10650) to πΥ(2S, 3S) and πΥ(1S) agrees very well with Belle's measurement. We also predict the similar ratios for Zc(3900), Zc(4020), RZc₍₃₉₀₀₎≈1.3 and RZc₍₄₀₂₀₎≈4.7. Hopefully the πψ(2S) mode, and ratios RZc₍₃₉₀₀₎ and RZc₍₄₀₂₀₎ will be measured by the BESIII and Belle collaborations in the near future, which shall be very helpful to understand the underlying dynamics of these exotic states.