Do nuclear collisions create a locally equilibrated quark–gluon plasma?

The European Physical Journal C

P. Romatschke¹ 

[1] Department of Physics, University of Colorado at Boulder, 390 UCB, 80309, Boulder, CO, USA;Center for Theory of Quantum Matter, University of Colorado, 80309, Boulder, CO, USA;

关键词: Effective Field Theory;    Quasinormal Mode;    Nuclear Collision;    Pressure Anisotropy;    Gradient Expansion;   

DOI  :  10.1140/epjc/s10052-016-4567-x

来源: Springer

【 摘 要 】

Experimental results on azimuthal correlations in high energy nuclear collisions (nucleus–nucleus, proton–nucleus, and proton–proton) seem to be well described by viscous hydrodynamics. It is often argued that this agreement implies either local thermal equilibrium or at least local isotropy. In this note, I present arguments why this is not the case. Neither local near-equilibrium nor near-isotropy are required in order for hydrodynamics to offer a successful and accurate description of experimental results. However, I predict the breakdown of hydrodynamics at momenta of order seven times the temperature, corresponding to a smallest possible QCD liquid drop size of 0.15 fm.

【 授权许可】

CC BY