In the Nambu--Jona-Lasinio model with Polyakov loops, we explore the relation
between the deconfinement and chiral phase transitions within the mean-field
approximation. We focus on the phase structure of the model and study the
susceptibilities associated with corresponding order parameters.Comment: 6 pages, 2 figures, contribution to the proceedings of the 19th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions
(QM2006), November 14-20 2006, Shanghai, Chin