Kinetic theory of a longitudinally expanding system of scalar particles

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 ${\varphi }^4$ 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.

26 figures, 47 pages

References in corpus (9)

• The Color Glass Condensate
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• On the equivalence between the Boltzmann equation and classical field theory at large occupation numbers
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• Approach to equilibrium in weakly coupled nonabelian plasmas
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Cited by in corpus (16)

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• Evolution to the Quark-Gluon Plasma
• Initial State Quantum Fluctuations in the Little Bang
• Time evolution of linearized gauge field fluctuations on a real-time lattice
• Some Aspects of the Theory of Heavy Ion Collisions
• Kinetic description of Bose-Einstein condensation with test particle simulations
• Thermalization of overpopulated systems in the 2PI formalism
• Minijet quenching in non-equilibrium quark-gluon plasma
• Kinetic approach to a relativistic Bose-Einstein condensate
• Time-Dependent Observables in Heavy Ion Collisions II: in Search of Pressure Isotropization in the ${\phi }^4$ Theory
• Kinetic approach to a relativistic BEC with inelastic processes
• Damping of gravitational waves in f(R) gravity
• Kinetic theory of a longitudinally expanding system
• Early Time Dynamics and the Bulk