Coupled-channel analysis of the X(3872)

Understand

The X(3872) is studied as an axial-vector charmonium state in the multichannel framework of the Resonance-Spectrum-Expansion quark-meson model, previously applied to a variety of other puzzling mesonic resonances.

• Included are the open-charm pseudoscalar-vector and vector-vector channels, the most important of which is the S-wave $\bar{D}^{*0}D^{0}$ + $D^{*0}\bar{D}^{0}$ channel, which practically coincides with the X(3872) structure.
• The two free parameters of the model are tuned so as to roughly reproduce the $\chi_{c1}(3511)$ mass as well as the enhancement just above the $\bar{D}^{*0}D^{0}$ / $D^{*0}\bar{D}^{0}$ threshold.
• The present model is able to describe the shape of the latter data quite well.