Reheating after the Supercooled Phase Transitions with Radiative Symmetry Breaking

TL;DR

This paper explores how the universe reheats after supercooled phase transitions caused by radiative symmetry breaking, detailing mechanisms depending on the RSB scale and implications for dark matter production.

Contribution

It provides a comprehensive analysis of reheating processes post-supercooling in RSB theories, including dark matter production and different energy transfer mechanisms.

Findings

Reheating can occur via decays of the RSB field or dark photon transfer, depending on the RSB scale.

Dark matter, specifically sterile neutrinos at 100 MeV, can be produced during reheating.

Efficient reheating is achievable through different channels based on the RSB scale relative to the electroweak scale.

Abstract

Theories with radiative symmetry breaking (RSB) lead to first-order phase transitions and the production of gravitational waves as well as primordial black holes if the supercooling period lasted long enough. Here we explain how to efficiently reheat the universe after such period in the above-mentioned class of theories. Two cases are possible, depending on whether the RSB scale is much larger than the electroweak (EW) symmetry breaking scale or not. When it is, the dominant reheating mechanism can be the decays of the field responsible for RSB in the Standard Model (SM) sector. We point out that in a similar way dark matter (DM) can be produced and we analyze in some detail the case of a sterile-neutrino, finding that the full DM abundance is reproduced when this particle is at the $10^2$ MeV scale in a well-motivated SM completion. When the RSB scale is not much larger than the EW symmetry breaking scale, we find that efficient reheating always occurs when the energy density of the false vacuum is first entirely transferred to a dark photon and then to SM fermions via dark-photon decays.