X(4260) revisited: A coupled channel perspective

Abstract

We calculate the probabilities of various charmed meson molecules for X(4260) under the framework of the 3 P 0 model. The results indicate that, even though heavy quark spin symmetry forbids S wave coupling of D 1D to the 3 S 1 charmonia [ψ(nS)], the D wave coupling is allowed and not negligible. Under this symmetry, the D 1D can couple to 3 D 1 charmonia [ψ(nD)] via both S and D waves, and the overall coupling is around three times larger than that of ψ(nS). The X(4260) cannot be a pure molecule but a mixture of a charmonium and various charmed meson components. Since the D 1D couples strongly to ψ(nD), our results suggest that, in the D 1D molecular picture, the charmonium core of X(4260) is ψ(nD) instead of ψ(nS). As a result, the experimental fact that the R ratio has a dip around 4.26 GeV can be understood in the D 1D molecular picture of the X(4260).

Prediction of an exotic state around 4240 MeV with JPC=1−+ as the CDong1, Lin2, Zou3 2020Phys. Rev. DSelf Cite296230View full textAdd to dashboardCite

“…Since the Y(4260) may be a mixture of DD 1 + c.c. molecule and ψ(nD) [34], then a more commonly used Λ 0 ≈ 1.5 GeV leads to a 1 −+ DD 1 + c.c. molecule with a mass around 4280 MeV.…”

χb(3P) multiplet revisited: Hyperfine mass splitting and radiative transitions

“…The matrix elements ψ f | r |ψ i are obtained numerically; for further details, we refer our studies [12,30]. From Eq.…”

“…These wave functions are in momentum space, and they are obtained by the Fourier transformation of the eigenfunctions of the bare Hamiltonian H 0 . More details can be found in our earlier works [12,30].…”

The Y(4260) and Y(4360) enhancements within coupled-channels

“…An idea in which the Y(4260) would be a "molecular" state, with a cc D-wave core coupled to channel DD 1 , may be found in Ref. [16]. Moreover, it is possible that the Y(4360), on its turn, might be generated by a similar mechanism as the Y(4260), where the dominant interference would involve the DD 1 + DD 1 thresholds.…”