May 6 – 12, 2012
Peniche, Portugal
Europe/Lisbon timezone

Is the X(3872) a molecule?

May 7, 2012, 5:30 PM
Peniche, Portugal

Peniche, Portugal

Hotel Praia Norte, Av. Monsenhor Bastos, 2520-206 Peniche, Portugal


Susana Coito (IST-Lisbon)


Recently, we have successfully described [1] the controversial X(3872) charmonium resonance as a normal axial-vector ($J^{PC}=1^{++}$) $c\bar{c}$ state, but non-perturbatively unitarised and mass-shifted owing to several OZI-allowed and OZI-suppressed decay channels. Nevertheless, many authors still consider the X(3872) a meson-meson molecule, due to its very close proximity to the $D^0D^{*0}$ threshold. It is argued [2] that, because of this closeness, the X(3872) will have a molecular-type wave function, with a strongly dominant $D^0D^{*0}$ component, irrespective of the mechanism creating the state. In this talk, I shall present results from a simplified study of this issue, employing a two-channel model, i.e., one channel for the confined axial-vector $c\bar{c}$ state and another for the dominant S-wave $D^0D^{*0}$ decay component. Harmonic-oscillator wave functions will be used for the confinement part and a delta-shell potential for transitions between the $c\bar{c}$ and $D^0D^{*0}$ channels, thus mimicking string breaking that gives rise to $^3P_0$ quark-pair creation. Probabilities of the two wave-function components will be computed as in Ref. [3], for different bound-state pole positions approaching the $D^0D^{*0}$ threshold from below. [1] Susana Coito, George Rupp, and Eef van Beveren, Eur. Phys. J. C 71 (2011) 1762 [arXiv:1008.5100 [hep-ph]]. [2] Eric Braaten and Meng Lu, Phys. Rev. D 76 (2007) 094028 [arXiv:0709.2697 [hep-ph]]. [3] E. van Beveren, C. Dullemond, and T.A. Rijken, Z. Phys. C 19 (1983) 275.

Primary author

Susana Coito (IST-Lisbon)


Prof. Eef van Beveren (CFC-Universidade de Coimbra) George Rupp (IST)

Presentation materials