Thermally corrected masses and freeze-in dark matter: a case study

TL;DR

This paper explores how thermal mass corrections influence freeze-in dark matter production, especially via forbidden channels, within a $U(1)_{L_-L_}-$extended model compatible with muon g-2 data.

Contribution

It introduces the impact of thermal mass corrections on forbidden channel dark matter production in a $U(1)_{L_-L_}$ model, highlighting their phenomenological significance.

Findings

Thermal corrections significantly affect dark matter mass and production.

Forbidden channels can enable dark matter generation at high temperatures.

The model remains consistent with recent muon g-2 measurements.

Abstract

If coupled \emph{feebly} to the Standard Model bath, a dark matter can evade the severe constraints from the direct search experiments. At the same time, such interactions help produce dark matter via the freeze-in mechanism. The freeze-in scenario becomes more interesting if one also includes the thermal masses of the different particles involved in the dark matter phenomenology. Incorporating such thermal corrections opens up the possibility of dark matter production via forbidden channels that remain kinematically disallowed in the standard freeze-in setup. Motivated by this, we investigate such freeze-in production of the dark matter in a minimally extended $U(1)_{L_\mu-L_\tau}$ framework that remains consistent with the recent muon $(g-2)$ data. Here, the role of the dark matter is played by the scalar with a non-trivial charge under the additional symmetry $U(1)_{L_\mu-L_\tau}$. This scalar dark matter obtains a thermally corrected mass at high temperatures for a not-so-small self-coupling. We show that the thermal correction to the dark matter mass plays a significant role in the dark matter phenomenology.