English

Is the X(3872) a molecule?

High Energy Physics - Phenomenology 2012-11-06 v1 High Energy Physics - Experiment

Abstract

Because of the controversial X(3872) meson's very close proximity to the D0Dˉ0D^0\bar{D}^{*0} threshold, this charmonium-like resonance is often considered a meson-meson molecule. However, a molecular wave function must be essentially of a meson-meson type, viz. D0Dˉ0D^0\bar{D}^{*0} in this case, with no other significant components. We address this issue by employing a simple two-channel Schr\"odinger model, in which the JPC=1++J^{PC}=1^{++} ccˉc\bar{c} and D0Dˉ0D^0\bar{D}^{*0} channels can communicate via the 3P0^3P_0 mechanism, mimicked by string breaking at a sharp distance aa. Thus, wave functions and their probabilities are computed, for different bound-state pole positions approaching the D0Dˉ0D^0\bar{D}^{*0} threshold from below. We conclude that at the PDG X(3872) mass and for reasonable values of aa, viz. 2.0 to 3.0 GeV1^{-1}, the ccˉc\bar{c} component remains quite substantial and certainly not negligible, despite accounting for only about 6 to 10% of the total wave-function probability, owing to the naturally long tail of the D0Dˉ0D^0\bar{D}^{*0} component.

Keywords

Cite

@article{arxiv.1209.1313,
  title  = {Is the X(3872) a molecule?},
  author = {S. Coito and G. Rupp and E. van Beveren},
  journal= {arXiv preprint arXiv:1209.1313},
  year   = {2012}
}

Comments

Contribution to the International Meeting "Excited QCD", Peniche, Portugal, 06 - 12 May 2012; 6 pages, 2 figures (4 plots), 2 tables, Acta Physica Polonica style

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