https://doi.org/10.1140/epja/i2002-10280-8
Mott effect and
dissociation at the quark-hadron phase transition
1
Department of Physics University of Rostock, D-18051, Rostock, Germany
2
Bogoliubov Laboratory for Theoretical Physics, JINR Dubna, 141980, Dubna, Russia
3
Laboratory for Information Technologies, JINR Dubna, 141980, Dubna, Russia
4
Oak Ridge National Laboratory, TN 37831-6373, Oak Ridge, USA
5
Department of Physics and Astronomy, University of Tennessee, TN 37996-1501, Knoxville, USA
* e-mail: david.blaschke@physik.uni-rostock.de
We investigate the in-medium modification of pseudoscalar and vector mesons in a QCD-motivated chiral quark model by solving the Dyson-Schwinger equations for quarks and mesons at finite temperature for a wide mass range of meson masses, from light (,
) to open-charm (D, D
*) states. At the chiral/deconfinement phase transition, the quark-antiquark bound states enter the continuum of unbound states and become broad resonances (hadronic Mott effect). We calculate the in-medium cross-sections for charmonium dissociation due to collisions with light hadrons in a chiral Lagrangian approach, and show that the D- and D
*-meson spectral broadening lowers the threshold for charmonium dissociation by
- and
-mesons. This leads to a step-like enhancement in the reaction rate. We suggest that this mechanism for enhanced charmonium dissociation may be the physical mechanism underlying the anomalous
suppression observed by NA50.
© Società Italiana di Fisica and Springer-Verlag, 2003