We calculate the area of a marginally trapped surface formed by a head-on collision of gravitational shock waves in AdSD. We use this to obtain a lower bound on the entropy produced after the collision. A comparison to entropy production in heavy ion collisions is included. We also discuss an O(D − 2) remnant of conformal symmetry which is present in a class of gravitational shock wave collisio...

The next great energy frontier in Relativistic Heavy Ion Collisions is quickly approaching with the completion of the Large Hadron Collider and the ATLAS experiment is poised to make important contributions in understanding QCD matter at extreme conditions. While designed for high-pT measurements in high-energy p+ p collisions, the detector is well suited to study many aspects of heavy ion coll...

Using a multiphase transport model, we study the relative importance of J/c suppression mechanisms due to plasma screening, gluon scattering, and hadron absorption in heavy ion collisions at the Relativistic Heavy Ion Collider. We find that for collisions between heavy nuclei such as Au1Au, both plasma screening and gluon scattering are important. As a result, the effect due to absorption by ha...

Using a multiphase transport model, we study the relative importance of J/ψ suppression mechanisms due to plasma screening, gluon scattering, and hadron absorption in heavy ion collisions at the Relativistic Heavy Ion Collider. We find that for collisions between heavy nuclei such as Au+Au, both plasma screening and gluon scattering are important. As a result, the effect due to absorption by ha...

Modifications in the production pattern of heavy quark bound states have long been considered to provide sensitive signatures for the thermal properties of dense matter created in heavy ion collisions. The original concept of Matsui and Satz for quarkonium suppression as signature for deconfinement in heavy ion collisions has been challenged recently through lattice studies of spectral function...

The nuclear modification factor is derived using Tsallis non-extensive statistics in relaxation time approximation. The variation of the nuclear modification factor with transverse momentum for different values of the non-extensive parameter, q, is also observed. The experimental data from RHIC and LHC are analysed in the framework of Tsallis non-extensive statistics in a relaxation time approx...

a total of 38, 300 traffic collisions have occurred in tehran, the capital of iran, during 1973. 5, 655 of these collisions in 6, 700 injuries and 560 deaths are selected and discussed. there has been no difference between the accident rates in working and holidays. winter has had the lowest rate, and accidents have been in direct relationship with the crowdedness and heavy traffic periods. nin...

I outline experimental results on heavy ion collisions at the Relativistic Heavy Ion Collider for a non-technical audience. This includes: elliptic flow and nearly ideal hydrodynamics; the suppression of hard particles and the ratio RAA; and electromagnetic signals, including dileptons and direct photons. Especially puzzling is why the behavior of heavy (charm) quarks appears to be so similar t...

Heavy quarks are copiously produced in ultra-peripheral heavy ion collisions. In the strong electromagnetic fields, cc and bb are produced by photonuclear and two-photon interactions; hadroproduction can occur in grazing interactions. We present the total cross sections, quark transverse momentum and rapidity distributions, as well as the QQ invariant mass spectra from the three production chan...

This contribution summarizes the main experimental results presented at the 2009 Quark Matter conference concerning single and dilepton production in proton and heavy ion collisions at high energy. The dilepton invariant mass spectrum has been measured over a range that extends from the π0 mass to the Υ mass, and for various collision energies at SPS, Fermilab, Hera and RHIC. This paper focuses...