Complementarity between Cosmic String Gravitational Waves and long-lived particle searches in a laboratory

TL;DR

This paper explores how gravitational wave observations and laboratory searches for long-lived particles can jointly reveal details about the dark sector, especially in scenarios involving cosmic strings and early matter domination.

Contribution

It demonstrates the complementarity of gravitational wave detectors and laboratory experiments in probing dark sectors with long-lived particles and cosmic strings.

Findings

Combined signals can better constrain dark sector parameters.

Certain parameter spaces produce observable signatures in both GW and lab experiments.

The study provides explicit models illustrating this complementarity.

Abstract

Cosmic strings are powerful witnesses to cosmic events including any period of early matter domination. If such a period of matter domination was catalysed by metastable, long-lived particles, then there will be complementary signals to ascertain the nature of dark sector in experiments detecting primordial features in the gravitational wave (GW) power spectrum and laboratory searches for long-lived particles. We give explicit examples of global and local U(1) gauge extended dark sectors to demonstrate such a complementarity as the union of the two experiments reveals more information about the dark sector than either experiment. Demanding that Higgs-portal long-lived scalar be looked for, in various experiments such as DUNE, FASER, FASER-II, MATHUSLA, SHiP, we identify the parameter space which leads to complementary observables for GW detectors such as LISA and ET.