Gravitational waves from first-order phase transition in a simple axion-like particle model
Abstract
We consider a gauge-singlet complex scalar field Φ with a global U(1) symmetry that is spontaneously broken at some high energy scale fa. As a result, the angular part of the Φ-field becomes an axion-like particle (ALP) . We show that if the Φ-field has a non-zero coupling κ to the Standard Model Higgs boson, there exists a certain region in the parameter space where the global U(1) symmetry-breaking induces a strongly first order phase transition, thereby producing stochastic gravitational waves that are potentially observable in current and future gravitational-wave detectors. In particular, we find that future gravitational-wave experiments such as TianQin, BBO and Cosmic Explorer could probe a broad range of the energy scale 103 GeV lesssim fa lesssim 108 GeV, independent of the ALP mass. Since all the ALP couplings to the Standard Model particles are proportional to inverse powers of the energy scale fa (up to model-dependent Script O(1) coefficients), the gravitational-wave detection prospects are largely complementary to the current laboratory, astrophysical and cosmological probes of the ALP scenarios.
- Publication:
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Journal of Cosmology and Astroparticle Physics
- Pub Date:
- November 2019
- DOI:
- 10.1088/1475-7516/2019/11/006
- arXiv:
- arXiv:1905.00891
- Bibcode:
- 2019JCAP...11..006B
- Keywords:
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- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 30 pages, 11 figures, minor changes, version accepted by JCAP