Cosmologically safe QCD axion as a present from extra dimension
We propose a QCD axion model where the origin of PQ symmetry and suppression of axion isocurvature perturbations are explained by introducing an extra dimension. Each extra quark–antiquark pair lives on branes separately to suppress PQ breaking operators. The size of the extra dimension changes afte...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2015-11-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269315006449 |