Pseudo-FIMP dark matter in presence of a SIMP

TL;DR

This paper investigates the dynamics of pseudo-FIMP dark matter in the presence of SIMP particles, analyzing model-independent scenarios and a specific two-scalar model, with implications for relic density and detectability.

Contribution

It provides a model-independent analysis of pFIMP-SIMP interactions and introduces a simple two-scalar model with symmetry stabilizations, exploring parameter space constraints.

Findings

Relic density constraints are addressed for pFIMP-SIMP scenarios.

Detectability of pFIMP is limited but possible via thermal loops with light mediators.

Parameter space satisfying unitarity and self-interaction constraints is identified.

Abstract

Pseudo-feebly Interacting Massive Particle (pFIMP) has been postulated in two component dark matter (DM) scenarios, where it has feeble interaction with the visible sector, but sizeable one with a thermal bath partner. In this work, we study the possibility and dynamics of pFIMP in presence of a Strongly Interacting Massive Particle (SIMP), which is well known to solve too-big-to-fail and core-vs-cusp problems. Our analysis is primarily model-independent via solving coupled Boltzmann equations, with negligible DM-DM conversion adhering to pure SIMP-FIMP limit, and then with larger DM-DM conversion rate pertaining to SIMP-pFIMP limit. We also illustrate the simplest model yielding pFIMP-SIMP set-up having two scalars stabilised under $\mathbb{Z}_2\otimes \mathbb{Z}_3$ symmetry, and explore the accessible parameter space after addressing relic density, unitarity, self interaction constraints etc. pFIMP detectability is limited in such circumstances, but possible via a thermal DM loop when the SIMP has a visible sector interaction via light mediator.