Hydrodynamic modeling of deconfinement phase transition in nuclear collisions

The (3+1)-dimensional ideal hydrodynamics is used to simulate collisions of gold nuclei with bombarding energies from 1 to 160 GeV per nucleon. The initial state is represented by two cold Lorentz-boosted nuclei. Two equations of state: with and without the deconfinement phase transition are used. We have investigated dynamical trajectories of compressed baryon-rich matter as functions of various thermodynamical variables. The parameters of collective flow and hadronic spectra are calculated. It is shown that presence of the deconfinement phase transition leads to increase of the elliptic flow and to flattening of proton rapidity distributions.Comment: 11 pages, 6 figure

Charm quenching in heavy-ion collisions at the LHC

D-meson suppression in Pb-Pb collisions at the LHC due to charm quark in-medium energy loss is estimated within a model that describes the available quenching measurements at RHIC. The result is compared to that previously published by the author. The expected sensitivity of the ALICE experiment for studying charm energy loss via fully-reconstructed D^0-meson decays is also presented.Comment: 8 pages, 3 figures. To appear in the proceedings of Hot Quarks 2004: Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions, Taos Valley, New Mexico, 18-24 July 2004. Submitted to J. Phys.

A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHC Energies

Standard jet finding techniques used in elementary particle collisions have not been successful in the high track density of heavy-ion collisions. This paper describes a modified cone-type jet finding algorithm developed for the complex environment of heavy-ion collisions. The primary modification to the algorithm is the evaluation and subtraction of the large background energy, arising from uncorrelated soft hadrons, in each collision. A detailed analysis of the background energy and its event-by-event fluctuations has been performed on simulated data, and a method developed to estimate the background energy inside the jet cone from the measured energy outside the cone on an event-by-event basis. The algorithm has been tested using Monte-Carlo simulations of Pb+Pb collisions at $\sqrt{s}=5.5$ TeV for the ALICE detector at the LHC. The algorithm can reconstruct jets with a transverse energy of 50 GeV and above with an energy resolution of $\sim30$.Comment: 13 pages, 7 figure