Gravitational waves from first-order electroweak phase transition in a model with light sgoldstinos

TL;DR

This paper explores how light sgoldstinos can induce a first-order electroweak phase transition, producing gravitational waves detectable by future space-based observatories, and discusses related collider phenomenology.

Contribution

It introduces a novel mechanism where sgoldstinos trigger the EWPT and calculates the resulting gravitational wave signals within a consistent effective theory.

Findings

First-order EWPT can be triggered by sgoldstino interactions with SM particles.

The gravitational wave signals are within the sensitivity of LISA, BBO, and DECIGO.

The effective theory remains perturbative up to high scales, above 10^8 GeV.

Abstract

We study previously unexplored possibility of triggering the first order electroweak phase transition (EWPT) by interactions of the Standard Model (SM) particles with the sector responsible for low scale supersymmetry breaking. The low-energy theory apart from the SM particles contains additional scalar degrees of freedom -- sgoldstinos -- which contribute to the effective scalar potential and thus can trigger the first order EWPT. Remarkably, the latter requires only moderate couplings in the scalar sector. The perturbative description in terms of the effective theory seems formally to be applicable upto the scale of supersymmetry breaking: the Landau pole in the scalar sector is above $10^8$-$10^9$ GeV. We calculate the gravitational wave signal generated at this transition (it can be tested, e.g. by LISA, BBO and DECIGO) and briefly discuss the collider phenomenology of this scenario.