QCD thermalization: Ab initio approaches and interdisciplinary connections

Abstract

C. Effective Field Theory for high parton densities: the Color Glass Condensate 8 This term can alternatively [115] be written as Tr [ρ log(U −∞,∞ )]. 9 Sub-leading terms were discussed in [117,118].

Development of transverse flow at small and large opacities in conformal kinetic theory

“…Despite significant progress in understanding the onset of hydrodynamic behavior in QCD plasmas (see e.g. [30,31] for recent reviews), calculations performed in this regard are typically subject to simplifying assumptions, e.g. modeling the early stages of heavy-ion collisions in terms of a transversely homogenous Bjorken flow, and are therefore not (yet) able to capture the competing effects of longitudinal and transverse expansion in small collision systems.…”

How many particles do make a fluid? Qualifying collective behavior in expanding ultracold gases

“…A proton-proton collision can not reach local thermal equilibrium, however, an effective hydrodynamic description for the development of anisotropic flows may remain appropriate. These kind of questions have triggered in recent times a vast body of work [55,56,57]. Such approaches suggest, notably, that systems that do not reach local thermal equilibrium remain governed by effective constitutive relations formally equivalent to those of hydrodynamics.…”

Collective flow in single-hit QCD kinetic theory

“…It builds on a picture arising from perturbative QCD in which partons undergoing elastic scattering and radiate medium-induced collinear radiation. This effective theory has been extensively employed to study how non-abelian gauge theories thermalize and how the hydrodynamization takes place in heavy-ion collisions in the weak coupling limit [13][14][15][16][17][18][19][20][21] (see also [22,23]). It has also been used to study how hard partons are hydrodynamized in the QCD medium leading to jet quenching [24,25] (see also [26][27][28][29]).…”