In-medium Yang-Mills equations: a derivation and canonical quantization

The equations for Yang-Mills field in a medium are derived in a linear approximation with respect to the gauge coupling parameter and the external field. The obtained equations closely resemble the macroscopic Maxwell equations. A canonical quantization is performed for a family of Fermi-like gauges in the case of constant and diagonal (in the group indices) tensors of electric permittivity and magnetic permeability. The physical subspace is defined and the gauge field propagator is evaluated for a particular choice of the gauge. The propagator is applied for evaluation of the cross-section of ellastic quark scattering in the Born approximation. Possible applications to Cherenkov-type gluon radiation are commented briefly.Comment: 27 pages, references added, version extended with emphasis on non-Abelian gauge group impact on medium characteristics. To appear in J. Phys.

Chemical equilibration and thermal dilepton production from the quark gluon plasma at finite baryon density

The chemical equilibration of a highly unsaturated quark-gluon plasma has been studied at finite baryon density. It is found that in the presence of small amount of baryon density, the chemical equilibration for gluon becomes slower and the temperature decreases less steeply as compared to the baryon free plasma. As a result, the space time integrated yield of dilepton is enhanced if the initial temperature of the plasma is held fixed. Even at a fixed initial energy density, the suppression of the dilepton yields at higher baryo-chemical potential is compensated, to a large extent, by the slow cooling of the plasma.Comment: Latex, 19 pages, 8 postscript figures. To appear in Phys. Rev.

Hadronization of a Quark-Gluon Plasma in the Chromodielectric Model

We have carried out simulations of the hadronization of a hot, ideal but effectively massive quark-gluon gas into color neutral clusters in the framework of the semi-classical SU(3) chromodielectric model. We have studied the possible quark-gluon compositions of clusters as well as the final mass distribution and spectra, aiming to obtain an insight into relations between hadronic spectral properties and the confinement mechanism in this model.Comment: 34 pages, 37 figure

Strange mesons from quark and hadron matter: a comparison

In a simplified model we study the hadronization of quark matter in an expanding fireball, in particular the approach to a final hadronic composition in equilibrium. Ideal hadron gas equilibrium constrained by conservation laws, the fugacity parametrization, as well as linear and non-linear coalescence approaches are recognized as different approximations to this in-medium quark fusion process. It is shown that color confinement requires a dependence of the hadronization cross section on quark density in the presence of flow (dynamical confinement).Comment: To appear in the Preoceedings of the Strange Matter 2000 Conference, Berkeley, July 20-25, 2000. 10 pages LaTeX, 2 ps figures, uses psfig and rotate.st

Bremsstrahlung from an Equilibrating Quark-Gluon Plasma

The photon production rate from a chemically equilibrating quark-gluon plasma likely to be produced at RHIC (BNL) and LHC (CERN) energies is estimated taking into account bremsstrahlung. The plasma is assumed to be in local thermal equilibrium, but with a phase space distribution that deviates from the Fermi or Bose distribution by space-time dependent factors (fugacities). The photon spectrum is obtained by integrating the photon rate over the space-time history of the plasma, adopting a boost invariant cylindrically symmetric transverse expansion of the system with different nuclear profile functions. Initial conditions obtained from a self-screened parton cascade calculation and, for comparison, from the HIJING model are used. Compared to an equilibrated plasma at the same initial energy density, taken from the self-screened parton cascade, a moderate suppression of the photon yield by a factor of one to five depending on the collision energy and the photon momentum is observed. The individual contributions to the photon production, however, are completely different in the both scenarios.Comment: 14 pages, 4 figures, shortened version to be published in Phys. Rev.

Finite Temperature Quark Matter and Supernova Explosion

We study the equation of state of quark matter at finite temperature, using a confinement model in which chiral symmetry remains broken in the deconfined phase. Implications for type II supernova explosion and for the structure and evolution of the proto-neutron star are discussed.Comment: RevTeX file + 5 postscript figure