When tan β meets all the mixing angles
Abstract
Models with two-Higgs-doublets and natural flavour conservation contain tan β =v2 /v1 as a physical parameter. We offer here a generalization of a recently proposed idea where only the Cabibbo angle, θc ≃ 0.22, was related to tan β by virtue of the D4 dihedral symmetry group. The original proposal consisted of a massless first generation of quarks and no mixing with the third generation. In our case, through the addition of a third Higgs doublet with a small vacuum-expectation-value but very large masses, thus later decoupling, all quarks become massive and quark mixing is fully reproduced. In fact, all quark mixing angles are expressed in terms of tan β and one recovers trivial mixing in the limit β → 0. We also explore the consequences in lepton mixing by adopting a type I seesaw mechanism with three heavy right-handed neutrinos.
- Publication:
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Physics Letters B
- Pub Date:
- October 2020
- DOI:
- 10.1016/j.physletb.2020.135750
- arXiv:
- arXiv:2001.07140
- Bibcode:
- 2020PhLB..80935750C
- Keywords:
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- High Energy Physics - Phenomenology
- E-Print:
- Major improvement to the overall content of the paper