Opening up the QCD axion window
We present a new mechanism to deplete the energy density of the QCD axion, making decay constants as high as f[subscript a] ≃ 1017 GeV viable for generic initial conditions. In our setup, the axion couples to a massless dark photon with a coupling that is moderately stronger than the axion coupling...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
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Springer Berlin Heidelberg
2018
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| Online Access: | http://hdl.handle.net/1721.1/116315 https://orcid.org/0000-0002-6809-7545 |
| _version_ | 1810984248907137024 |
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| author | Agrawal, Prateek Marques-Tavares, Gustavo Xue, Wei |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Agrawal, Prateek Marques-Tavares, Gustavo Xue, Wei |
| author_sort | Agrawal, Prateek |
| collection | MIT |
| description | We present a new mechanism to deplete the energy density of the QCD axion, making decay constants as high as f[subscript a] ≃ 1017 GeV viable for generic initial conditions. In our setup, the axion couples to a massless dark photon with a coupling that is moderately stronger than the axion coupling to gluons. Dark photons are produced copiously through a tachyonic instability when the axion field starts oscillating, and an exponential suppression of the axion density can be achieved. For a large part of the parameter space this dark radiation component of the universe can be observable in upcoming CMB experiments. Such dynamical depletion of the axion density ameliorates the isocurvature bound on the scale of inflation. The depletion also amplifies the power spectrum at scales that enter the horizon before particle production begins, potentially leading to axion miniclusters. Keywords: Cosmology of Theories beyond the SM, CP violation |
| first_indexed | 2024-09-23T10:59:25Z |
| format | Article |
| id | mit-1721.1/116315 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T10:59:25Z |
| publishDate | 2018 |
| publisher | Springer Berlin Heidelberg |
| record_format | dspace |
| spelling | mit-1721.1/1163152022-09-27T16:23:21Z Opening up the QCD axion window Agrawal, Prateek Marques-Tavares, Gustavo Xue, Wei Massachusetts Institute of Technology. Department of Physics Xue, Wei We present a new mechanism to deplete the energy density of the QCD axion, making decay constants as high as f[subscript a] ≃ 1017 GeV viable for generic initial conditions. In our setup, the axion couples to a massless dark photon with a coupling that is moderately stronger than the axion coupling to gluons. Dark photons are produced copiously through a tachyonic instability when the axion field starts oscillating, and an exponential suppression of the axion density can be achieved. For a large part of the parameter space this dark radiation component of the universe can be observable in upcoming CMB experiments. Such dynamical depletion of the axion density ameliorates the isocurvature bound on the scale of inflation. The depletion also amplifies the power spectrum at scales that enter the horizon before particle production begins, potentially leading to axion miniclusters. Keywords: Cosmology of Theories beyond the SM, CP violation United States. Department of Energy (DE-SC-00012567) United States. Department of Energy (DE-SC-00015476) 2018-06-14T17:04:43Z 2018-06-14T17:04:43Z 2018-03 2017-12 2018-03-11T04:21:56Z Article http://purl.org/eprint/type/JournalArticle 1029-8479 http://hdl.handle.net/1721.1/116315 Agrawal, Prateek, et al. “Opening up the QCD Axion Window.” Journal of High Energy Physics, vol. 2018, no. 3, Mar. 2018. © The Authors https://orcid.org/0000-0002-6809-7545 en http://dx.doi.org/10.1007/JHEP03(2018)049 Journal of High Energy Physics Creative Commons Attribution http://creativecommons.org/licenses/by/4.0/ The Author(s) application/pdf Springer Berlin Heidelberg Springer Berlin Heidelberg |
| spellingShingle | Agrawal, Prateek Marques-Tavares, Gustavo Xue, Wei Opening up the QCD axion window |
| title | Opening up the QCD axion window |
| title_full | Opening up the QCD axion window |
| title_fullStr | Opening up the QCD axion window |
| title_full_unstemmed | Opening up the QCD axion window |
| title_short | Opening up the QCD axion window |
| title_sort | opening up the qcd axion window |
| url | http://hdl.handle.net/1721.1/116315 https://orcid.org/0000-0002-6809-7545 |
| work_keys_str_mv | AT agrawalprateek openinguptheqcdaxionwindow AT marquestavaresgustavo openinguptheqcdaxionwindow AT xuewei openinguptheqcdaxionwindow |