Coupled-channel and screening effects in charmonium spectrum

Abstract

Using the same quenched limit as input, we compare the charmonium spectra predicted by two different models, i.e., the coupled-channel model and the screened potential model in the mass region below 4 GeV, in which the contributions from decay channels involving P-wave (as well as even higher excited) D mesons can be neglected. We find that the two models have similar global features in describing the charmonium spectrum since they approximately embody the same effect of the vacuum polarization of dynamical light quark pairs. Adopting these models will be helpful to clarify the nature of the newly discovered charmonium or charmoniumlike states; and the coupled-channel model is more adept in investigating the influences of open-charm thresholds on the charmonium spectrum. In particular, we show the S-wave decay coupling effect on lowering the c1 ð2PÞ mass toward the D " D Ã threshold, in support of the assignment of the Xð3872Þ as a c1 ð2PÞ-dominated charmonium state.

Higher radial and orbital excitations in the charmed meson family

“…Applying the idea in Ref. [74] to our case, we can similarly study a charmed meson spectrum. However, it is a complicated task and can be assessed at a future theoretical work 1 .…”

“…The mass suppression can be caused by both the screening and coupled channel effects. Although the screening effect can be almost equivalent description of the coupled channel effect, we need to emphasize that the screening effect cannot depict the near-threshold effect as the coupled channel effect does [74], which is obtained by studying charmonium spectrum. The authors of this paper made a comparison of the results by adopting the screening and coupled channel effects.…”

The hidden-charm pentaquark and tetraquark states

“…One notes that the screened potential and the coupled-channel model roughly play the same role in lowering the mass of the χ c1 (2P) charmonium state, which can reach 3901 MeV and is close to the mass of the X(3872) [602].…”

Charmonium spectrum with a Dirac potential model in the momentum space

“…This coupling causes a shift in the energy, generally leading to a reduction in the masses of the quarkonia [43][44][45] in the high-lying states. This effect can also be incorporated, in a more phenomenological way, through the screening of the interaction potential [60,61] which produces a similar global result.…”