We study neutrino masses and mixing in supersymmetric models without R parity and with generic soft Supersymmetry breaking terms. Neutrinos acquire mass from various sources: tree level neutrino-neutralino mixing, loop effects and non-renormalizable operators. Abelian horizontal symmetries (invoked to explain the smallness and hierarchy in quark parameters) replace R parity in suppressing neutrino masses. We find lower bounds on the mixing angles: sin θij ≳ m(li-)/m(lj-) (i < j) and unusual order of magnitude predictions for neutrino mass ratios: Hi(νe)/m(νμ) ∼ sin2 θ12; m(νi)/m(ντ) ∼ 10-7 sin2 θi3 (i = 1, 2). Bounds from laboratory experiments exclude mντ ≳ 3 MeV and cosmological constraints exclude mντ ≳ 100 eV. Neither the solar nor the atmospheric neutrino problems are likely to be solved by νμ - νe oscillations. These conclusions can be evaded if holomorphy plays an important role in the lepton Yukawa couplings.
|ジャーナル||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|出版物ステータス||Published - 1996 9 19|
ASJC Scopus subject areas
- Nuclear and High Energy Physics