Peccei-Quinn Relaxion
arXiv:1709.10025 · doi:10.1007/JHEP01(2018)121
Abstract
The relaxation mechanism, which solves the electroweak hierarchy problem without relying on TeV scale new physics, crucially depends on how a Higgs-dependent back-reaction potential is generated. In this paper, we suggest a new scenario in which the scalar potential induced by the QCD anomaly is responsible both for the relaxation mechanism and the Peccei-Quinn mechanism to solve the strong CP problem. The key idea is to introduce the relaxion and the QCD axion whose cosmic evolutions become quite different depending on an inflaton-dependent scalar potential. Our scheme raises the cutoff scale of the Higgs mass up to 10^7 GeV, and allows reheating temperature higher than the electroweak scale as would be required for viable cosmology. In addition, the QCD axion can account for the observed dark matter of the universe as produced by the conventional misalignment mechanism. We also consider the possibility that the couplings of the Standard Model depend on the inflaton and become stronger during inflation. In this case, the relaxation can be implemented with a sub-Planckian field excursion of the relaxion for a cutoff scale below 10 TeV.
arXiv comment14 pages, 1 figure; minor changes, accepted for publication in JHEP
References in corpus (14)
- Cosmological Relaxation of the Electroweak Scale
- Axions : Theory and Cosmological Role
- A Clockwork Axion
- Realizing the relaxion from multiple axions and its UV completion with high scale supersymmetry
- Phenomenology of relaxion-Higgs mixing
- Lattice QCD input for axion cosmology
- Cosmological Higgs-Axion Interplay for a Naturally Small Electroweak Scale
- Bare Higgs mass at Planck scale
- Constraints on Relaxion Windows
- Pure Natural Inflation
- Relaxion: A Landscape Without Anthropics
- Low-Scale D-term Inflation and the Relaxion
- Elliptic Inflation: Interpolating from natural inflation to -inflation
- Natural cliff inflation