198 research outputs found
Geometrical CP violation in multi-Higgs models
We introduce several methods to obtain calculable phases with geometrical
values that are independent of arbitrary parameters in the scalar potential.
These phases depend on the number of scalars and on the order of the discrete
non-Abelian group considered. Using these methods we present new geometrical CP
violation candidates with vacuum expectation values that must violate CP (the
transformation that would make them CP conserving is not a symmetry of the
potential). We also extend to non-renormalisable potentials the proof that more
than two scalars are needed to obtain these geometrical CP violation
candidates.Comment: 8 pages, 2 figures. v2: table added, accepted by JHE
Quasi-degenerate neutrinos and tri-bi-maximal mixing
Assuming high-energy tri-bi-maximal mixing we study the radiative running of
leptonic mixing angles and obtain limits on the high-energy scale from
requiring consistency with the observed mixing. We construct a model in which a
non-Abelian discrete family symmetry leads both to a quasi-degenerate neutrino
mass spectrum and to near tri-bi-maximal mixing.Comment: 7 pages, to appear in the proceedings of DISCRETE'0
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