Inverted mass hierarchy from scaling in the neutrino mass matrix: Low and high energy phenomenology

Journal Article · Sat Sep 01 04:00:00 EDT 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.76.053003· OSTI ID:21027678

Blum, A; Rodejohann, W ^[1]; Mohapatra, R N ^[2]

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1. Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, D-69029 Heidelberg (Germany)
2. Department of Physics and Maryland Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States) and Sektion Physik, Ludwig-Maximilians-Universitaet Muenchen, Theresienstrasse 37a, D-80333 Munich (Germany) and Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

Best-fit values of recent global analyses of neutrino data imply large solar neutrino mixing, vanishing U{sub e3}, and a nonmaximal atmospheric neutrino mixing angle {theta}{sub 23}. We show that these values emerge naturally by the hypothesis of scaling in the Majorana neutrino mass matrix, which states that the ratios of its elements are equal. It also predicts an inverted hierarchy for the neutrino masses. We point out several advantages and distinguishing tests of the scaling hypothesis compared to the L{sub e}-L{sub {mu}}-L{sub {tau}} flavor symmetry, which is usually assumed to provide an understanding of the inverted hierarchy. Scenarios which have initially vanishing U{sub e3} and maximal atmospheric neutrino mixing are shown to be unlikely to lead to nonmaximal {theta}{sub 23} while simultaneously keeping U{sub e3} zero. We find a peculiar ratio of the branching ratios {mu}{yields}e{gamma} and {tau}{yields}e{gamma} in supersymmetric seesaw frameworks, which only depends on atmospheric neutrino mixing and results in {tau}{yields}e{gamma} being unobservable. The consequences of the scaling hypothesis for high energy astrophysical neutrinos at neutrino telescopes are also investigated. Then we analyze a seesaw model based on the discrete symmetry D{sub 4}xZ{sub 2} leading to scaling in the low energy mass matrix and being capable of generating the baryon asymmetry of the Universe via leptogenesis. The relevant CP phase is identical to the low energy Majorana phase, and successful leptogenesis requires an effective mass for neutrinoless double beta decay larger than 0.045 eV.

• OSTI ID: 21027678
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 5 Vol. 76; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASTROPHYSICS
ASYMMETRY
BARYONS
BRANCHING RATIO
CP INVARIANCE
DOUBLE BETA DECAY
EFFECTIVE MASS
ELECTRONS
EV RANGE
FLAVOR MODEL
MATRICES
PHOTONS
REST MASS
SOLAR NEUTRINOS
STANDARD MODEL
SUPERSYMMETRY
TAU PARTICLES
UNIVERSE
WEINBERG ANGLE