Particle distributions in electroweak tachyonic preheating

Abstract

We consider the out-of-equilibrium (quasi-) particle number distributions of the Higgs and W-fields during electroweak tachyonic preheating. We model this process by a fast quench, and perform classical real-time lattice simulations in the SU(2)-Higgs model in three dimensions. We discuss how to define particle numbers and effective energies using two-point functions in Coulomb and unitary gauge, and consider some of the associated problems. After an initial exponential growth in effective particle numbers, the system stabilises, allowing us to extract effective masses, temperatures and chemical potentials for the particles.