Primordial black holes as a probe of strongly first-order electroweak phase transition

TL;DR

This paper explores how primordial black holes formed during a strongly first-order electroweak phase transition could serve as observable probes for new physics models, linking cosmology with particle physics and future observational capabilities.

Contribution

It demonstrates that primordial black holes from the electroweak phase transition can be detectable and used to test specific models with dimension 6 and 8 operators in the standard model effective field theory.

Findings

Primordial black holes of about 10^{-5} solar mass can be produced during the electroweak phase transition.

Current and future microlensing experiments can potentially detect these black holes.

The study links black hole observations with models of strongly first-order electroweak phase transition.

Abstract

Primordial black holes can be produced by density fluctuations generated from delayed vacuum decays of first-order phase transition. The primordial black holes generated at the electroweak phase transition have masses of about $10^{-5}$ solar mass. Such primordial black holes in the mass range can be tested by current and future microlensing observations, such as Subaru HSC, OGLE, PRIME and Roman telescope. Therefore, we may be able to explore new physics models with strongly first-order electroweak phase transition via primordial black holes. We examine this possibility by using models with first-order electroweak phase transition in the standard model effective field theory with dimension 6 and 8 operators. We find that depending on parameters of the phase transition a sufficient number of primordial black holes can be produced to be observed by above mentioned experiments. Our results would suggest that primordial black holes can be used as a new probe of models with strongly first-order electroweak phase transition, which has complementarity with measurements of the triple Higgs boson coupling at future collider experiments and observations of gravitational waves at future space-based interferometers.