Abstract:
Different hadron transverse momentum spectra are calculated in a non-extensive statistical, quark-coalescence model. For the low-pT part a gluonic string contribution is conjectured, its length distribution and fractality are fitted to RHIC data.

Abstract:
The behavior of kaons and pions in hot non strange quark matter, simulating neutron matter, is investigated within the SU(3) Nambu-Jona-Lasinio [NJL] and in the Enlarged Nambu-Jona-Lasinio [ENJL] (including vector pseudo-vector interaction) models. At zero temperature, it is found that in the NJL model, where the phase transition is first order, low energy modes with K-, Pi+ quantum numbers, which are particle-hole excitations of the Fermi sea, appear. Such modes are not found in the ENJL model and in NJL at finite temperatures. The increasing temperature has also the effect of reducing the splitting between the charge multiplets.

Abstract:
The properties of finite lumps of strange quark matter (strangelets) with emphasis on the two scenarios of producing strange matter in relativistic heavy ion collisions are summarized. As an outlook, the possibility of short-lived strange composites and charmed matter are discussed for coming heavy ion experiments.

Abstract:
We investigate the properties of strange quark matter at zero temperature including medium effects. The quarks are considered as quasiparticles which acquire an effective mass generated by the interaction with the other quarks of the dense system. The effective quark masses are derived from the zero momentum limit of the dispersion relations following from an effective quark propagator obtained from resumming one-loop self energy diagrams in the hard dense loop approximation. This leads to a thermodynamic selfconsistent description of strange quark matter as an ideal Fermi gas of quasiparticles. Within this approach we find that medium effects reduce the overall binding energy with respect to $^{56}Fe$ of strange quark matter. For realistic values of the strong coupling constant strange quark matter is not absolutely stable. The application to pure strange quark matter stars shows that medium effects have, nevertheless, no impact on the mass-radius relation of the stars. However, a phase transition to hadronic matter at the surface of the stars becomes more likely.

Abstract:
The properties of strange quark matter at zero temperature are investigated including medium effects. The quarks are considered as quasiparticles which acquire an effective mass generated by the interaction with the other quarks of the dense system. Within this approach we find that these medium effects reduce the binding energy of strange quark matter with respect to $^{56}Fe$.

Abstract:
Motivated by the need for a solid state strange quark matter to better explain some observational phenomena, we discussed possibility of color singlet cluster formation in cold strange quark matter by a rough calculation following the excluded volume method proposed by Clark et al (1986) and adopted quark mass density dependent model with cubic scaling. It is found that 70% to 75% of volume and 80% to 90% of baryon number is in clusters at temperature from 10MeV to 50MeV and 1 to 10 times nuclear density.

Abstract:
We have derived the popularly used parametrization formulae for quark masses at low densities and modified them at high densities within the mass-density-dependent model. The results are applied to investigate the lowest density for the possible existence of strange quark matter at zero temperature.

Abstract:
Astrophysicists distinguish between three different types of compact stars. These are white dwarfs, neutron stars, and black holes. The former contain matter in one of the densest forms found in the Universe which, together with the unprecedented progress in observational astronomy, make such stars superb astrophysical laboratories for a broad range of most striking physical phenomena. These range from nuclear processes on the stellar surface to processes in electron degenerate matter at subnuclear densities to boson condensates and the existence of new states of baryonic matter--like color superconducting quark matter--at supernuclear densities. More than that, according to the strange matter hypothesis strange quark matter could be more stable than nuclear matter, in which case neutron stars should be largely composed of pure quark matter possibly enveloped in thin nuclear crusts. Another remarkable implication of the hypothesis is the possible existence of a new class of white dwarfs. This article aims at giving an overview of all these striking physical possibilities, with an emphasis on the astrophysical phenomenology of strange quark matter. Possible observational signatures associated with the theoretically proposed states of matter inside compact stars are discussed as well. They will provide most valuable information about the phase diagram of superdense nuclear matter at high baryon number density but low temperature, which is not accessible to relativistic heavy ion collision experiments.

Abstract:
3-flavor quark matter (strange quark matter; SQM) can be stable or metastable for a wide range of strong interaction parameters. If so, SQM can play an important role in cosmology, neutron stars, cosmic ray physics, and relativistic heavy-ion collisions. As an example of the intimate connections between astrophysics and heavy-ion collision physics, this Chapter gives an overview of the physical properties of SQM in bulk and of small-baryon number strangelets; discusses the possible formation, destruction, and implications of lumps of SQM (quark nuggets) in the early Universe; and describes the structure and signature of strange stars, as well as formation and detection of strangelets in cosmic rays. It is concluded, that astrophysical and laboratory searches are complementary in many respects, and that both should be pursued to test the intriguing possibility of a strange ground state for hadronic matter, and (more generally) to improve our knowledge of the strong interactions.

Abstract:
Because of the mass density-dependence, an extra term should be added to the expression of pressure. However, it should not appear in that of energy according to both the general ensemble theory and basic thermodynamic principle. We give a detail derivation of the thermodynamics with density-dependent particle masses. With our recently determined quark mass scaling, we study strange quark matter in this new thermodynamic treatment, which still indicates a possible absolute stability as previously found. However, the density behavior of the sound velocity is opposite to the previous finding, but consistent with one of our recent publication. We have also studied the structure of strange stars using the obtained equation of state.