Comparison of models of critical opacity in the quark-gluon plasma

In this work we discuss two methods of calculation of quark propagation in the quark-gluon plasma. Both methods make use of the Nambu-Jona-Lasinio model. The essential difference of these calculations is the treatment of deconfinement. A model of confinement is not included in the work of Gastineau, Blanquier, and Aichelin (e-print hep-ph/0404207), however, the meson states they consider are still bound for temperatures greater than the deconfinement temperature T_c. On the other hand, our model deals with unconfined quarks and includes a description of the qq̅ resonances found in lattice QCD studies that make use of the maximum entropy method. We compare the qq̅ cross sections calculated in these models.