Abstract
Abstract
Thermal axion production in the early universe goes through several mass thresholds, and the resulting rate may change dramatically across them. Focusing on the KSVZ and DFSZ frameworks for the invisible QCD axion, we perform a systematic analysis of thermal production across thresholds and provide smooth results for the rate. The QCD phase transition is an obstacle for both classes of models. For the hadronic KSVZ axion, we also deal with production at temperatures around the mass of the heavy-colored fermion charged under the Peccei-Quinn symmetry. Within the DFSZ framework, standard model fermions are charged under this symmetry, and additional thresholds are the heavy Higgs bosons masses and the electroweak phase transition. We investigate the cosmological implications with a specific focus on axion dark radiation quantified by an effective number of neutrino species and explore the discovery reach of future CMB-S4 surveys.
Publisher
Springer Science and Business Media LLC
Subject
Nuclear and High Energy Physics
Reference126 articles.
1. C. A. Baker et al., An Improved experimental limit on the electric dipole moment of the neutron, Phys. Rev. Lett. 97 (2006) 131801 [hep-ex/0602020] [INSPIRE].
2. J. M. Pendlebury et al., Revised experimental upper limit on the electric dipole moment of the neutron, Phys. Rev. D 92 (2015) 092003 [arXiv:1509.04411] [INSPIRE].
3. nEDM collaboration, Measurement of the permanent electric dipole moment of the neutron, Phys. Rev. Lett. 124 (2020) 081803 [arXiv:2001.11966] [INSPIRE].
4. L. Ubaldi, Effects of theta on the deuteron binding energy and the triple-alpha process, Phys. Rev. D 81 (2010) 025011 [arXiv:0811.1599] [INSPIRE].
5. M. Dine, L. Stephenson Haskins, L. Ubaldi and D. Xu, Some Remarks on Anthropic Approaches to the Strong CP Problem, JHEP 05 (2018) 171 [arXiv:1801.03466] [INSPIRE].
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