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The Approach to Equilibrium in Strongly Interacting Matter


The purpose of this Workshop is to critically review the recent progress on the theory and phenomenology of early time dynamics in relativistic heavy ion collisions from RHIC to LHC energies, to examine the various approaches on thermalization and existing issues, and to formulate new research efforts for the future.

Specific topics we plan to address include:

  • Experimental evidence for equilibration/isotropization. What do the latest experimental results say about these questions? How model (in)dependent are these conclusions? Since the pressure isotropization is important for hydrodynamics, is there a way to assess the longitudinal pressure from measurements?
  • Comparison of various approaches. Various tools and approaches have been employed to study thermalization: kinetic theory, 2-particle irreducible formalism, classical statistical field theory, strong coupling techniques such as AdS/CFT,... Do their range of applicability overlap? How do they compare (in terms of ease of application, and in their results)?
  • Dependence on the initial conditions and couplings. Typically, the late time behavior of a system confined in a fixed volume will only depend on the conserved quantities, regardless of the details of the initial conditions. However, transient regimes will differ in general. When a system is free to expand in empty space, is there still a (partial) loss of details about the intial conditions? Are there various limiting regimes, depending on initial conditions and/or values of couplings? In heavy ion collisions, the initial conditions just after the collision are characterized by a strong coherent color field surrounded by small fluctuations. What is the role played by this coherent field? What is the role of plasma instabilities, in particular, at later stages of the evolution?
  • Turbulent cascades and Bose-Einstein condensation. Various studies performed in toy scalar models have shown that, if the initial condition is overpopulated, turbulent cascades may form and the particle excess can condense in the zero mode. This excess is gradually destroyed later on by inelastic processes. In heavy ion collisions, the initial condition is similarly overpopulated, but elastic and inelastic processes are parametrically of the same order in the coupling in contrast to the scalar field theory case. How does the formation of turbulent cascades and the question under which conditions a Bose-Einstein condensate could form compare between scalar and non-Abelian gauge field theory? What roles do the inelastic processes play during the evolution of a non-Abelian gauge field system with initial overpopulation?


Presentations will be mainly by invitation. We expect to be able to accommodate a limited number of contributed talks. If you are interested in presenting a contributed talk, please contact one of the organizers.

Evening Event

Registered attendees are invited to attend the optional banquet dinner; free of charge for registered participants.

Banquet Details
Brookhaven Center (Bldg. 30) South Room
Thursday Night, April 3, 2014

Workshop Organizers

  • Juergen Berges (Heidelberg U)
  • Jean-Paul Blaizot (Saclay)
  • Francois Gelis (Saclay)
  • Jinfeng Liao (Indiana U & RBRC)
  • Raju Venugopalan (BNL)


Click on the "Workshop Information" tab above to find accommodation information.

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Last Modified: December 27, 2017