Strong C P and flavor in multi-Higgs theories
Year: 2025
Type: article
Abstract: We introduce a class of multi-Higgs doublet extensions of the Standard Model that solve the strong C P problem with profound consequences for the flavor sector. The Yukawa matrices are constrained to have many zero entries by a “Higgs-flavor” symmetry, G HF , that acts on Higgs and quark fields. The violation of both C P and G HF occurs in the Higgs mass matrix so that, for certain choices of G HF charges, the strong C P parameter θ ¯ is zero at tree level. Radiative corrections to θ ¯ are computed in this class of theories. They vanish in realistic two-Higgs doublet models with G HF = Z 3 . We also construct realistic three-Higgs models with G HF = U ( 1 ) , where the one-loop results for θ ¯ are model-dependent. Requiring θ ¯ < 10 − 10 has important implications for the flavor problem by constraining the Yukawa coupling and Higgs mass matrices. Contributions to θ ¯ from higher-dimension operators are computed at one loop and can also be sufficiently small, although the hierarchy problem of this class of theories is worse than in the Standard Model.
DOI: 10.1103/rxml-5gd2
Authors: Lawrence Hall, Claudio Andrea Manzari, Bea Noether
Institution: Lawrence Berkeley National Laboratory
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4410532906