QUARK CONFINEMENT AND THE PROPERTIES OF QUARK MATTER.

The properties of two-flavor quark matter are investigated with a model which incorporates the confinement by density-dependent quark masses (CDDM). The results are compared with those in the conventional MIT bag model. It is found that the density behavior of quark matter in the two models are significantly different. Specially, the second derivative of the energy density can be negative in the CDDM while that in the bag model is always positive. This makes the velocity of sound very different in both models. [ABSTRACT FROM AUTHOR]