Unusual bound states of quark matter within the Nambu-Jona-Lasinio model -art. no. 034901

Properties of dense quark matter in and out of chemical equilibrium are stu died within the SU(3) Nambu-Jona-Lasinio model. In addition to the four-fer mion scalar and vector terms the model includes also the six-fermion flavor mixing interaction. First we study a new form of deconfined matter, meso-m atter, which is composed of an equal number of quarks and antiquarks. It ca n be thought of as a strongly compressed meson gas where mesons are melted into their elementary constituents, quarks and antiquarks. Strongly bound s tares in this quark-antiquark matter are predicted for all flavor combinati ons of q (q) over bar pails. The maximum binding energy reaches up to 180 M eV per q (q) over bar pair for mixtures with about 70% of strange (s (s) ov er bar) pairs. Equilibrated baryon-rich quark matter with various flavor co mpositions is also studied. In this case only shallow bound states appear i n systems with a significant admixture (about 40%) of strange quarks (stran gelets). Their binding energies are quite sensitive to the relative strengt hs of scalar and vector interactions. The common property of all these boun d states is that they appear at high particle densities when the chiral sym metry is nearly restored. Thermal properties of meso-matter as well as chem ically equilibrated strange quark matter are also investigated. Possible de cay modes of these bound states are discussed.