# SIMPler realisation of Scalar Dark Matter

## TL;DR

This paper proposes a simple scalar dark matter model stabilized by a $Z_3$ symmetry, featuring a light scalar mediator to enhance self-interactions, and derives an analytic freeze-out solution for the SIMP mechanism, comparing it with WIMP scenarios.

## Contribution

It introduces a novel scalar SIMP dark matter framework with a $Z_3$ symmetry and provides an analytic freeze-out solution, expanding understanding of self-interacting dark matter models.

## Key findings

- Large parameter space consistent with relic density and cluster data.
- Analytic solution for $3 o 2$ freeze-out process.
- Comparison between SIMP and WIMP realizations.

## Abstract

With growing agony of not finding a dark matter (DM) particle in direct search experiments so far (for example in XENON1T), frameworks where the freeze-out of DM is driven by number changing processes within the dark sector itself and do not contribute to direct search, like Strongly Interacting Massive Particle (SIMP) are gaining more attention. In this analysis, we ideate a simple scalar DM framework stabilised by $Z_3$ symmetry to serve with a SIMP-like DM ($\chi$) with additional light scalar mediation ($\phi$) to enhance DM self interaction. We identify that a large parameter space for such DM is available from correct relic density and self interaction constraints coming from Bullet or Abell cluster data. We derive an approximate analytic solution for freeze-out of the SIMP like DM in Boltzmann Equation describing $3 \to 2$ number changing process within the dark sector. We also provide a comparative analysis of the SIMP like solution with the Weakly Interacting Massive Particle (WIMP) realisation of the same model framework here.