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arXiv · 2009.01452

A Tale of Two-U(1) Axion Models

Dong Hu·Hao-Ran Jiang·Hao-Lin Li·Ming-Lei Xiao·Jiang-Hao Yu
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Abstract

The $U(1)$ global symmetry to solve the strong $CP$ problem could be the remnant of multi-$U(1)$ symmetries from QCD and hidden strong dynamics. Both Peccei-Quinn $U(1)$ and dynamical $U(1)$ are described uniformly, based on which we classify various mixed two-$U(1)$ models to solve both strong $CP$ and quality problems. We propose a moose diagram method with different fermion assignments to directly read relations between $CP$ phases, which illustrate how strong $CP$ problem is solved in terms of cancellation between $CP$ phases. In two axion models, we find the lightest axion is still same as QCD axion at infrared region, while one axion model with $Z_2$ symmetry enhances the axion mass spectrum. Our discussions can be extended to multi-axion cases.

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Dong Hu, Hao-Ran Jiang, Hao-Lin Li, Ming-Lei Xiao, Jiang-Hao Yu. 2020-09-03. A Tale of Two-U(1) Axion Models. https://doi.org/10.1103/physrevd.103.095025

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