Related papers: Two Photon Physics in pp and AA Collisions
The rapid thermalization of quarks and gluons in the initial stages of relativistic heavy-ion collisions is treated using analytic solutions of a nonlinear diffusion equation with schematic initial conditions, and for gluons with boundary…
Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC…
We review some basic concepts of Relativistic Heavy Ion Physics and discuss our understanding of some key results from the experimental program at the Relativistic Heavy Ion Collider (RHIC). We focus in particular on the early time dynamics…
I review some important results from RHIC experiments. They were obtained in a unique environment for studying QCD bulk matter at temperatures and densities that surpass the limits where hadrons can exist as individual entities, raising the…
Strange particles have been a very important observable in the search for a deconfined state of strongly interacting matter, the quark-gluon plasma (QGP), which is expected to be formed in ultra-relativistic heavy ion collisions. We review…
We study the photoproduction process of dileptons in heavy ion collision at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energys. The equivalent photon approximation, which equates the electromagnetic field of…
The two arguably most generic phenomena seen in ultra-relativistic heavy ion collisions are the flow of essentially all soft hadronic observables and the quenching of essentially all hard hadronic observables. Limiting the discussion to…
Quarks and gluons are the fundamental constituents of nucleons. Their interactions rather than their mass, is responsible for $99\%$ of the mass of all visible matter in the universe. Measuring the fundamental properties of matter has had a…
The initial collision geometry, including the reaction plane, is crucial for interpreting collective phenomena in relativistic heavy-ion collisions, yet it remains experimentally inaccessible through conventional measurements. Recent…
Relativistic heavy ion collisions produce thousands of particles, and it is sometimes difficult to believe that these processes allow for a theoretical description directly in terms of the underlying theory - QCD. However once the parton…
We argue that features of hadron production in relativistic nuclear collisions, mainly at CERN-SPS energies, may be explained by the existence of three forms of matter: Hadronic Matter, Quarkyonic Matter, and a Quark-Gluon Plasma. We…
Prompt photon production in ultra-relativistic heavy-ion collisions provides a calibrated probe for the study of the properties of high energy density QCD matter. Especially interesting are the measurements of $\gamma$-tagged jets where the…
Relativistic heavy ion physics studies the phenomena that occur when a very large (in units of QCD scale $\Lambda_{\rm QCD}$) amount of energy is deposited into a large (in units of $\Lambda^{-3}_{\rm QCD}$) volume, creating an extended in…
This article is based on my Proceedings for the 47th Course of the International School of Subnuclear Physics on the Most Unexpected at LHC and the Status of High Energy Frontier, Erice, Sicily, Italy, 2009. Results from the PHENIX…
Using the recently published model for the collisional energy loss of heavy quarks (Q) in a Quark Gluon Plasma (QGP), based on perturbative QCD (pQCD) with a running coupling constant, we study the interaction between heavy quarks and…
Results on physics at RHIC using outgoing leptons and photons will be presented from Au+Au collisions at nucleon-nucleon c.m. energies $\sqrt{s_{NN}}=130$ and 200 GeV and from p-p collisions at $\sqrt{s}=200$ GeV. Introduction and…
We calculate the thermal photon transverse momentum spectra and elliptic flow in $\sqrt{s_{NN}} = 200$ GeV Au+Au collisions at RHIC and in $\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC, using an ideal-hydrodynamical framework which…
We investigate top anti-top quark pair production in lead-lead collisions at the Large Hadron Collider with nucleon-nucleon center of mass energy of 5.5 TeV. Due to the very high temperature and energy density created in heavy ion…
The strong electromagnetic fields of heavy nuclei can produce a wide variety of two-photon and photonuclear reactions at relativistic ion colliders. We present recent results from the STAR collaboration on these `ultra-peripheral'…
This presentation discusses some recently active topics in the theoretical interpretation of high energy heavy ion collisions at the LHC and at RHIC. We argue that the standard paradigm for understanding the spacetime evolution of the bulk…