Color-glass condensate

About: Color-glass condensate is a research topic. Over the lifetime, 885 publications have been published within this topic receiving 35169 citations.

Strongly Interacting Matter Matter at Very High Energy Density: 3 Lectures in Zakopane

Abstract: These lectures concern the properties of strongly interacting matter at very high energy density. I begin with the Color Glass Condensate and the Glasma, matter that controls the earliest times in hadronic collisions. I then describe the Quark Gluon Plasma, matter produced from the thermalized remnants of the Glasma. Finally, I describe high density baryonic matter, in particular Quarkyonic matter. The discussion will be intuitive and based on simple structural aspects of QCD. There will be some discussion of experimental tests of these ideas.

Isotropization and thermalization in heavy-ion collisions

Abstract: We argue that isotropization and, consequently, thermalization of the system of gluons and quarks produced in an ultrarelativistic heavy-ion collision does not follow from Feynman diagram analysis to any order in the coupling constant. We conclude that the apparent thermalization of quarks and gluons, leading to success of perfect fluid hydrodynamics in describing heavy-ion collisions at RHIC, can only be attributed to the non-perturbative QCD effects not captured by Feynman diagrams. We proceed by modeling these non-pertrubative thermalization effects using viscous hydrodynamics. We point out that matching Color Glass Condensate inital conditions with viscous hydrodynamics leads to a continuous evolution of all the components of the energy-momentum tensor and, unlike the case of ideal hydrodynamics, does not give rise to a discontinuity in the longitudinal pressure. An important consequence of such a matching is a relationship between the thermalization time and shear viscosity: we observe that small viscosity leads to short thermalization time.

Decoherence and entropy production in relativistic nuclear collisions

Abstract: Short thermalization times of less than 1 fm/c for quark and gluon matter have been suggested by recent experiments at the Relativistic Heavy Ion Collider. It has been difficult to justify this rapid thermalization in first-principle calculations based on perturbation theory or the color glass condensate picture. Here, we address the related question of the decoherence of the gluon field, which is a necessary component of thermalization. We present a simplified leading-order computation of the decoherence time of a gluon ensemble subject to an incoming flux of Weizsaecker-Williams gluons. We also discuss the entropy produced during the decoherence process and its relation to the entropy in the final state that has been measured experimentally.

High baryon densities in heavy ion collisions at energies attainable at the BNL Relativistic Heavy-Ion Collider and the CERN Large Hadron Collider

Abstract: In very high-energy collisions nuclei are practically transparent to each other but produce very hot nearly baryon-free matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy-Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.

CGC, QCD saturation and RHIC data (Kharzeev-Levin-McLerran-Nardi point of view)

Abstract: We are going to discuss ion-ion and deuteron-nucleus RHIC data and show that they support, if not more, the idea of the new QCD phase: Colour Glass Condensate with saturated parton density.