Naturally Light Neutrinos and Unification in Theories with Low Scale Quantum Gravity

Abstract

Within low scale theories traditional see-saw and scalar triplet mechanisms, for neutrino mass suppression, do not work out anymore and for realistic model building some new ideas are needed. In this paper we suggest mechanism, different from existing ones, which provides natural suppression of the neutrino masses. The mechanism is realized through extended scalars of 4, 5 or 6 dimensional $SU(2{)}_L$ multiplets. Scenario, with fundamental mass scale $M_f$ in a $\sim 10^3$ TeV range, requires 4-plets guaranteeing neutrino masses $\stackrel{<}{\sim }1$ eV. For theories with $M_f=few\cdot 10$ TeV 5-plets should be involved, while in scenarios with $M_f=$ few TeV, 6-plets could be efficient. The considered mechanism could be successfully applied also for supersymmetric theories, building scenarios with various values of low $M_f$. Within considered models we also address the question of gauge coupling unification. For low scale unification, existence of compact extra dimensions turns out to be crucial. Due to additional scalar multiplets, some new examples of unification are found for both - non SUSY and SUSY cases. Within non SUSY scenarios introduced $SU(2{)}_L$ scalars take advantage and are important for successful unification.

LaTex, 1 eps figure, discussions and references added

References in corpus (13)

• A Large Mass Hierarchy from a Small Extra Dimension
• Infinitely Large New Dimensions
• Probing Large Extra Dimensions with Neutrinos
• An Early Proposal of "Brane World"
• Neutrino-induced upward stopping muons in Super-Kamiokande
• Status of the MSW Solutions to the Solar Neutrino Problem
• Neutrino Masses and Oscillations in Models with Large Extra Dimensions
• Self-Breaking of the Standard Model Gauge Symmetry
• Anomalous Flavor U(1): Predictive Texture For Bi-maximal Neutrino Mixing
• Supersymmetry Breaking, Fermion Masses and a Small Extra Dimension
• Updated Global Analysis of the Atmospheric Neutrino Data in terms of neutrino oscillations
• Electroweak Symmetry Breaking and Extra Dimensions
• Exponentially Small Supersymmetry Breaking from Extra Dimensions

Cited by in corpus (6)

• New Mechanism for Neutrino Mass Generation and Triply Charged Higgs Bosons at the LHC
• The signatures of the quintuplet leptons at the LHC
• Soft See-Saw: Radiative Origin of Neutrino Masses in SUSY Theories
• Texture Zero Neutrino Models and Their Connection with Resonant Leptogenesis
• Neutrino Mass Matrices from Two Zero 3x2 Yukawa Textures and Minimal d=5 Entries
• Alternative signatures of the quintuplet fermions at the LHC and future linear colliders