Neutrino masses from new generations

Abstract

We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present data can be accommodated with five generations and two right-handed neutrinos. Within this framework, we explore the parameter space regions which are currently allowed and could lead to observable effects in neutrinoless double beta decay, $\mu -e$ conversion in nuclei and $\mu \to e\gamma$ experiments. We also discuss the detection prospects at LHC.

28 pages, 4 figures. Version to be published. Some typos corrected. Improved figures 3 and 4

References in corpus (35)

• Evidence for oscillation of atmospheric neutrinos
• Direct Evidence for Neutrino Flavor Transformation from Neutral-Current Interactions in the Sudbury Neutrino Observatory
• First Results from KamLAND: Evidence for Reactor Anti-Neutrino Disappearance
• Massive neutrinos and cosmology
• Double Beta Decay, Majorana Neutrinos, and Neutrino Mass
• The Search for Heavy Majorana Neutrinos
• Phenomenology with Massive Neutrinos
• Latest Results from the Heidelberg-Moscow Double Beta Decay Experiment
• Three-flavour neutrino oscillation update
• GNO Solar Neutrino Observations: Results for GNOI
• Evidence for muon neutrino oscillation in an accelerator-based experiment
• The Atmospheric Neutrino Flavor Ratio from a 3.9 Fiducial Kiloton-Year Exposure of Soudan 2
• Quarks and Leptons Beyond the Third Generation
• Unitarity of the Leptonic Mixing Matrix
• Signatures for Majorana neutrinos at hadron colliders
• Four Statements about the Fourth Generation
• Heavy Majorana Neutrinos in the Effective Lagrangian Description: Application to Hadron Colliders
• Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters
• A superformula for neutrinoless double beta decay II: The short range part
• Robust Neutrino Constraints by Combining Low Redshift Observations with the CMB
• Measurement of WW Production and Search for the Higgs Boson in pp Collisions at sqrt(s) = 7 TeV
• Precision Constraints on Extra Fermion Generations
• pi/K -> e nu branching ratios to O(e^2 p^4) in Chiral Perturbation Theory
• Robust Cosmological Bounds on Neutrinos and their Combination with Oscillation Results
• Lepton Flavour Violation in the Presence of a Fourth Generation of Quarks and Leptons
• Search for muon-neutrino to electron-neutrino transitions in MINOS
• The smallest neutrino mass
• The NNLO gluon fusion Higgs production cross-section with many heavy quarks
• Simultaneous Extraction of the Fermi constant and PMNS matrix elements in the presence of a fourth generation
• Once more on extra quark-lepton generations and precision measurements
• Long Lived Fourth Generation and the Higgs
• Tau Physics: Theory Overview
• Fourth Family Neutrinos and the Higgs Boson
• 3-Neutrino Mass Spectrum from Combining Seesaw and Radiative Neutrino Mass Mechanisms
• Probing for Ultraheavy Quanta at LHC

Cited by in corpus (5)

• From the trees to the forest: a review of radiative neutrino mass models
• Higgs data confronts Sequential Fourth Generation Fermions in the Higgs Triplet Model
• On the nature of the fourth generation neutrino and its implications
• Fourth Generation Majorana Neutrinos
• Neutrino Masses and a Fourth Generation of Fermions