Populating secluded dark sector with ultra-relativistic bubbles

TL;DR

This paper investigates the production of dark matter during first order phase transitions involving bubble collisions, focusing on secluded dark sectors with heavy, potentially warm dark matter, and compares different production mechanisms.

Contribution

It introduces a detailed analysis of dark matter generation from bubble collisions in secluded sectors, including glueball dark matter and freeze-in processes, highlighting their distinct phenomenology.

Findings

Dark matter can be heavy and warm due to high initial velocities.

Glueball dark matter exhibits unique phenomenological properties.

Freeze-in production can be significant compared to bubble-plasma mechanisms.

Abstract

We study Dark Matter production during first order phase transitions from bubble-plasma collisions. We focus on scenarios where the Dark Matter sector is secluded and its interaction with the visible sector (including the Standard Model) originates from dimension-five and dimension-six operators. We find that such DM is generally heavy and has a large initial velocity, leading to the possibility of DM being warm today. We differentiate between the cases of weakly and strongly coupled dark sectors, where, in the latter case, we focus on glueball DM, which turns out to have very distinct phenomenological properties. We also systematically compute the Freeze-In production of the dark sector and compare it with the bubble-plasma DM abundances.