Gravitational waves as a probe of extended scalar sectors with the first order electroweak phase transition

TL;DR

This paper investigates gravitational wave signals from first order electroweak phase transitions in extended scalar sectors, showing potential detectability and their use as probes of new physics beyond the Standard Model.

Contribution

It provides a numerical evaluation of gravitational wave spectra without high temperature expansion in models with additional singlet scalars, highlighting their detectability and dependence on model parameters.

Findings

Gravitational waves from the phase transition can be detected by DECIGO and BBO.

Spectra are sensitive to the number of singlet fields and their masses.

Future observations can probe extended scalar sectors and phase transition dynamics.

Abstract

We discuss spectra of gravitational waves which are originated by the strongly first order phase transition at the electroweak symmetry breaking, which is required for a successful scenario of electroweak baryogenesis. Such spectra are numerically evaluated without high temperature expansion in a set of extended scalar sectors with additional N isospin-singlet fields as a concrete example of renormalizable theories. We find that the produced gravitational waves can be significant, so that they are detectable at future gravitational wave interferometers such as DECIGO and BBO. Furthermore, since the spectra strongly depend on N and the mass of the singlet fields, our results indicate that future detailed observation of gravitational waves can be in general a useful probe of extended scalar sectors with the first order phase transition.