Spin-2 Portal Dark Matter

TL;DR

This paper explores how a massive spin-2 particle can serve as an effective mediator between dark matter and the Standard Model, enabling dark matter production via freeze-in during reheating, often surpassing gravitational interactions.

Contribution

It introduces a generalized model with a spin-2 mediator as a portal, analyzing its effectiveness across various mass and temperature parameters during reheating.

Findings

Spin-2 mediators can dominate dark matter production over gravitational interactions.

The model's effectiveness varies with the spin-2 mass relative to reheating temperatures.

Systematic analysis covers different parameter regimes for the spin-2 mass.

Abstract

We generalize models invoking a spin-2 particle as a mediator between the dark sector and the Standard Model. We show that a massive spin-2 messenger can efficiently play the role of a portal between the two sectors. The dark matter is then produced via a freeze-in mechanism during the reheating epoch. In a large part of the parameter space, production through the exchange of a massive spin-2 mediator dominates over processes involving a graviton with Planck suppressed couplings. We perform a systematic analysis of such models for different values of the spin-2 mass relative to the maximum and the final temperature attained at reheating.