EPJ Web of Conferences (Jan 2018)

Threshold effects in hadron spectrum: a new spectroscopy?

  • Ortega P.G.,
  • Segovia J.,
  • Entem D.R.,
  • Fernández F.

DOI
https://doi.org/10.1051/epjconf/201818202094
Journal volume & issue
Vol. 182
p. 02094

Abstract

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The exploration of energies above the open-flavor threshold in the meson spectra has led to the appearance of unexpected states difficult to accommodate in the naive picture of a bound state of a quark and an antiquark. Many of such states are located close to meson-meson thresholds, which suggests that molecular structures may be a relevant component in the total wave function of such resonances. In this work, the state of meson-meson molecules calculations is reviewed, using a nonrelativistic constituent quark model that has been applied to a wide range of hadronic observables, and therefore all model parameters are completely constrained. The model has been able to reproduce, among others, the properties of the X(3872), described as a mixture of cc and DD* states, or the spectrum of the P-wave charm-strange mesons, which are well reproduced only if DK and D*K structures are taken into account. We show that such constituent quark model, which is able to describe the ordinary heavy meson spectra, is also capable of providing a good description of many new states recently reported.