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A New Class of Solutions to the Strong CP Problem with a Small Two-Loop theta

Darwin Chang·Wai-Yee Keung
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Abstract

We present a new class of models which produce zero theta (QCD} angle at the tree and one-loop level due to hermiticity of sub-blocks in the extended quark mass matrices. The structure can be maintained typically by non-abelian generation symmetry. Two examples are given for this class of solutions.

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Darwin Chang, Wai-Yee Keung. 2003-12-10. A New Class of Solutions to the Strong CP Problem with a Small Two-Loop theta. https://doi.org/10.1103/physrevd.70.051901

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