Baryon and Lepton Number Violation from Gravitational Waves

TL;DR

This paper proposes a distinctive gravitational wave signature arising from models with hierarchical symmetry breaking scales, combining signals from cosmic strings and phase transitions, relevant for gauged baryon and lepton number theories.

Contribution

It introduces a new gravitational wave signature model linking high-scale lepton number breaking and low-scale baryon number breaking in a unified framework.

Findings

Unique gravitational wave signal shape identified

Application to gauged baryon and lepton number models

Potential detectability in upcoming experiments

Abstract

We describe a unique gravitational wave signature for a class of models with a vast hierarchy between the symmetry breaking scales. The unusual shape of the signal is a result of the overlapping contributions to the stochastic gravitational wave background from cosmic strings produced at a high scale and a cosmological phase transition at a low scale. We apply this idea to a simple model with gauged baryon and lepton number, in which the high-scale breaking of lepton number is motivated by the seesaw mechanism for the neutrinos, whereas the low scale of baryon number breaking is required by the observed dark matter relic density. The novel signature can be searched for in upcoming gravitational wave experiments.