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arXiv · 1506.05580

Kinetic theory of a longitudinally expanding system of scalar particles

Thomas Epelbaum·Francois Gelis·Sangyong Jeon·Guy Moore·Bin Wu
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Abstract

A simple kinematical argument suggests that the classical approximation may be inadequate to describe the evolution of a system with an anisotropic particle distribution. In order to verify this quantitatively, we study the Boltzmann equation for a longitudinally expanding system of scalar particles interacting with a $\phi^4$ coupling, that mimics the kinematics of a heavy ion collision at very high energy. We consider only elastic $2\to 2$ scatterings, and we allow the formation of a Bose-Einstein condensate in overpopulated situations by solving the coupled equations for the particle distribution and the particle density in the zero mode. For generic CGC-like initial conditions with a large occupation number and a moderate coupling, the solutions of the full Boltzmann equation do not follow a classical attractor behavior.

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Thomas Epelbaum, Francois Gelis, Sangyong Jeon, Guy Moore, Bin Wu. 2015-06-18. Kinetic theory of a longitudinally expanding system of scalar particles. https://doi.org/10.1007/jhep09(2015)117

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