Asteroid-mass Primordial Black Holes as Dark Matter from Supersymmetry

TL;DR

This paper investigates how supersymmetric particles can enhance asteroid-mass primordial black hole formation, potentially explaining dark matter without conflicting with observational constraints.

Contribution

It demonstrates that supersymmetric extensions can produce a significant asteroid-mass PBH population compatible with dark matter, unlike the Standard Model.

Findings

Supersymmetric particles above 10^5 GeV enhance asteroid-mass PBH formation.

PBHs can account for all dark matter within supersymmetric models without violating bounds.

Standard Model configurations do not produce viable PBH dark matter candidates.

Abstract

We study the formation of asteroid-mass Primordial Black Holes (PBHs) as a dark matter candidate in supersymmetric extensions of the Standard Model. We show that the presence of heavy particles predicted in the Minimal Supersymmetric Standard Model (MSSM) can lead to a transient softening of the equation of state of the Universe during their non-relativistic transition, enhancing PBH formation. We compute the effective equation of state for different realizations of the MSSM mass spectrum, parametrized by three characteristic mass scales. Assuming a broad and approximately scale-invariant primordial curvature power spectrum, we evaluate the resulting PBH mass functions and compare them with current observational constraints. We find that, for supersymmetric masses above $\sim 10^5\,\mathrm{GeV}$, the PBH mass function is significantly enhanced in the asteroid-mass window, allowing PBHs to account for the total dark matter abundance without violating existing bounds. In contrast, within the Standard Model the same configurations lead to PBH mass functions that are observationally excluded. For lighter supersymmetric mass spectra, PBH production is shifted toward masses above $\sim 10^{22}\,\mathrm{g}$, which are strongly constrained by microlensing searches, thereby reducing their allowed contribution to the dark matter density.