Symmetries at ultrahigh energies and searches for neutrino oscillations

Abstract

Motivated by the possibility that new (gauge) symmetries which are broken at the grand- (string-) unification scale give rise to texture zeros in the fermion mass matrices which are at the origin of the hierarchy of masses and mixings we explore the effect of such zeros on the neutrino spectrum of SUSY-GUT models. We find that the quadratic-seesaw spectrum on which most expectations are focused is neither the only nor the most interesting possibility. Cases of strong ${\nu }_{\mu }-{\nu }_{\tau }$ or ${\nu }_e-{\nu }_{\tau }$ mixing are present for a specific texture structure of the Yukawa matrices and experimental evidence can thus throw some light on the latter. In contrast if the quadratic-seesaw scenario should be confirmed very little could be said about the symmetries of the Yukawa sector.

13 pages of LATEX

Cited by in corpus (6)

• Quasi-degenerate neutrinos from an abelian family symmetry
• Supersymmetry Hierarchy Problems and Anomalous Horizontal U(1) Symmetry
• Supersymmetric models with anomalous U(1) mediated supersymmetry breaking
• Textures for Neutrino Mass Matrices
• Anomalous $U(1)$ Mediated SUSY Breaking, Fermion Masses and Natural Suppression of FCNC and CP Violating Effects
• String Unification, Spaghetti Diagrams and Infra-Red Fixed Points