Kinetic equilibration in heavy ion collisions: The role of elastic processes

Serreau, Julien; Schiff, D.

doi:10.1088/1126-6708/2001/11/039

Cited by 27 publications

(28 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(15). For ultrarelativistic particles the inverse of R tr 22 is the mean path (or time) that particles should travel to become isotropic, and R 22 /R tr 22 is the average number of collisions, which each particle needs to drive the particle system into isotropy in momentum space.…”

Section: B R Tr 22mentioning

confidence: 99%

“…gives the time scale of the overall equilibration in absence of particle drift, which was used in [9,10,11,12,13,14,15] to calculate the time scale of thermalization within various dynamical scenarios of the expansion. It is crucial to see whether τ rel in the relaxation time approximation is equivalent to the mean transport path, because the latter determines the momentum isotropization time scale in a static system.…”

Section: Dependence Of the Transport Rate On The Definition Of Qmentioning

confidence: 99%

“…A widely used, yet simpler, method to characterize kinetic equilibration is to calculate or estimate the relaxation time τ rel [9,10,11,12,13,14,15]. In the relaxation time approximation the collision term is expressed by (f eq − f )/τ rel , where τ rel is assumed to be momentum independent and is then a global quantity that characterizes the kinetic equilibration time scale.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Transport rates and momentum isotropization of gluon matter in ultrarelativistic heavy-ion collisions

2007

View full text Add to dashboard Cite

To describe momentum isotropization of gluon matter produced in ultrarelativistic heavy-ion collisions, the transport rate of gluon drift and the transport collision rates of elastic (gg ↔ gg) as well as inelastic (gg ↔ ggg) perturbative quantum chromodynamics-(pQCD) scattering processes are introduced and calculated within the kinetic parton cascade Boltzmann approach of multiparton scatterings (BAMPS), which simulates the space-time evolution of partons. We define isotropization as the development of an anisotropic system as it reaches isotropy. The inverse of the introduced total transport rate gives the correct time scale of the momentum isotropization. The contributions of the various scattering processes to the momentum isotropization can be separated into the transport collision rates. In contrast to the transport cross section, the transport collision rate has an indirect but correctly implemented relationship with the collision-angle distribution. Based on the calculated transport collision rates from BAMPS for central Au+Au collisions atRelativistic Heavy Ion Collider energies, we show that pQCD gg ↔ ggg bremsstrahlung processes isotropize the momentum five times more efficiently than elastic scatterings. The large efficiency of the bremsstrahlung stems mainly from its large momentum deflection. Due to kinematics, 2 → N (N > 2) production processes allow more particles to become isotropic in momentum space and thus kinetically equilibrate more quickly than their back reactions or elastic scatterings. We also show that the relaxation time in the relaxation time approximation, which is often used, is strongly momentum dependent and thus cannot serve as a global quantity that describes kinetic equilibration.

show abstract

Section: B R Tr 22mentioning

confidence: 99%

Section: Dependence Of the Transport Rate On The Definition Of Qmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transport rates and momentum isotropization of gluon matter in ultrarelativistic heavy-ion collisions

2007

View full text Add to dashboard Cite

show abstract

“…Hard modes of the classical fields play the role of particles here. The equilibration processes with the minijet and saturation initial states were compared to each other in [49].…”

Section: Pos(cpod2006)042mentioning

confidence: 99%

Early stage thermalization via instabilities

Mrówczyński¹

2007

Proceedings of Critical Point and Onset of Deconfinement — PoS(CPOD2006)

View full text Add to dashboard Cite

“…Although the issue of early thermalization is still a matter of debate (see e.g. [21]), it seems important to consider the influence of the non-equilibrium evolution on the various experimental signatures of the produced matter and, in particular, on electromagnetic signals, which are sensitive to the earliest stages of the collision.…”

Section: Motivations and Overview Of Previous Workmentioning

confidence: 99%

Out-of-equilibrium electromagnetic radiation

Serreau

2004

J. High Energy Phys.

Self Cite

View full text Add to dashboard Cite

We derive general formulas for photon and dilepton production rates from an arbitrary non-equilibrated medium from first principles in quantum field theory. At lowest order in the electromagnetic coupling constant, these relate the rates to the unequal-time in-medium photon polarization tensor and generalize the corresponding expressions for a system in thermodynamic equilibrium. We formulate the question of electromagnetic radiation in real time as an initial value problem and consistently describe the virtual electromagnetic dressing of the initial state. In the limit of slowly evolving systems, we recover known expressions for the emission rates and work out the first correction to the static formulas in a systematic gradient expansion. Finally, we discuss the possible application of recently developed techniques in non-equilibrium quantum field theory to the problem of electromagnetic radiation. We argue, in particular, that the two-particle-irreducible (2PI) effective action formalism provides a powerful resummation scheme for the description of multiple scattering effects, such as the Landau-Pomeranchuk-Migdal suppression recently discussed in the context of equilibrium QCD.

show abstract

Kinetic equilibration in heavy ion collisions: The role of elastic processes

Cited by 27 publications

References 9 publications

Transport rates and momentum isotropization of gluon matter in ultrarelativistic heavy-ion collisions

Transport rates and momentum isotropization of gluon matter in ultrarelativistic heavy-ion collisions

Early stage thermalization via instabilities

Out-of-equilibrium electromagnetic radiation

Contact Info

Product

Resources

About