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 f a . 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 large region in the (f a , κ) 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 LISA, BBO and aLIGO+ could probe a broad range of the energy scale 10 3 GeV f a 10 8 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 f a (up to model-dependent O(1) coefficients), the gravitational-wave detection prospects are largely complementary to the current laboratory, astrophysical and cosmological probes of the ALP scenarios.

Peccei-Quinn phase transition at LIGO

“…However, in order to achieve a viable electroweak (EW) symmetry breaking, we need to tune κ Φ 2 ≈ µ 2 . This constraint has not allowed us to find a region of the parameter space where the PQ phase transition is strongly first-order (see also [12]).…”

“…Nevertheless, as we will see, the temperature of the phase transition can be actually slightly smaller than F a (by up to a factor ∼ 10), which in the end allows LIGO to probe these scenarios. The capability of LIGO to probe PQ phase transitions has also been pointed out and partially discussed in [11,12].…”

Singlet-doublet fermionic dark matter and gravitational waves in a two-Higgs-doublet extension of the Standard Model

“…In Figure 10 we have plotted and compared the GW intensities for the chosen benchmarks (Table V) DECIGO, aLIGO, aLIGO+ and LISA following Ref. [149,150]. The frequencies at which the GW intensities acquire maximum value are 10 −2 Hz, 7 × 10 −3 Hz, 3.80 × 10 −2 Hz and 3.40 × 10 −2 Hz for BPI, BPII, BPIII, and BPIV respectively.…”

Gravitational waves from phase transition in minimal SUSY U(1)B−L model

“…This dependence on the genuine Higgs mass term, or equivalently the Higgs portal coupling, has been studied in Ref. [20]. In SUSY models, the Higgs portal coupling is forbidden at the renormalizable level and hence is justifiably neglected.…”

“…(19) represents the tree-level potential. Eq (20). is the one-loop effective potential at zero-temperature, with µ being the renormalization scale in DR scheme.…”