Azimuthal asymmetry in transverse energy flow in nuclear collisions at high energies

The azimuthal pattern of transverse energy flow in nuclear collisions at RHIC and LHC energies is considered. We show that the probability distribution of the event-by-event azimuthal disbalance in transverse energy flow is essentially sensitive to the presence of the semihard minijet component.Comment: 6 pages, 2 figure

Strangeness Production in Chemically Non-Equilibrated Parton Plasma

Strangeness production was investigated during the equilibration of a gluon dominated parton plasma produced at RHIC and LHC energies. The time evolution of parton densities are followed by a set of rate equations in a 1-dimensional expanding system. The strangeness production will depend on the initial chemical equilibration level and in our case the parton densities will remain far from the full equilibrium. We investigate the influence of gluon fragmentation on final strangeness content.Comment: 12 pages (LaTeX) + 2 postscript figures (tarred, compressed, uuencoded) included. Review to appear in Proceedings of Strangeness'95, Tucson, Arizona, Jan. 4--6 1995. (American Institute of Physics

Where is the jet quenching in Pb+Pb collisions at 158 AGeV?

Because of the rapidly falling particle spectrum at large $p_T$ from jet fragmentation at the CERN SPS energy, the high-$p_T$ hadron distribution should be highly sensitive to parton energy loss inside a dense medium as predicted by recent perturbative QCD (pQCD) studies. A careful analysis of recent data from CERN SPS experiments via pQCD calculation shows little evidence of energy loss. This implies that either the life-time of the dense partonic matter is very short or one has to re-think about the problem of parton energy loss in dense matter. The hadronic matter does not seem to cause jet quenching in $Pb+Pb$ collisions at the CERN SPS. High-$p_T$ two particle correlation in the azimuthal angle is proposed to further clarify this issue.Comment: 4 pages with 2 ps figures. Minors changes are made in the text with updated references. Revised version to appear in Phys. Rev. Letter