scholarly journals HOW MAGNETIC IS THE NEUTRINO?

2007 ◽  
Vol 22 (27) ◽  
pp. 4891-4899 ◽  
Author(s):  
N. F. BELL
Keyword(s):  
Neutrino Mass ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
New Physics ◽  
Upper Bounds ◽  
Radiative Corrections ◽  
Neutrino Magnetic Moment ◽  
Majorana Neutrinos ◽  
Model Independent ◽  
Moment Bounds

The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment bounds are weaker than present experimental limits if μν is generated by new physics at ~ 1 TeV , and surpass current experimental sensitivity only for new physics scales > 10 – 100 TeV . The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.

A CLASS OF MODELS WITH LARGE NEUTRINO MAGNETIC MOMENT

1994 ◽  
Vol 09 (12) ◽  
pp. 2013-2032 ◽  
Author(s):  
DARWIN CHANG ◽  
W.-Y. KEUNG ◽  
IVAN PHILLIPS
Keyword(s):  
Neutrino Mass ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Neutrino Masses ◽  
Symmetry Principle ◽  
Neutrino Magnetic Moment ◽  
Symmetry Principles

We show how a list of symmetry principles can be used to generate a class of models in which the neutrino masses are suppressed while relatively large magnetic moments are allowed. The simplest example is a model for neutrino mass proposed by Zee some time ago. We show how the model can be improved based on the symmetry principle and we also demonstrate other models in this class which avoid some of the weakness in the simplest model.

scholarly journals Model Independent Naturalness Bounds on Magnetic Moments of Majorana Neutrinos

2007 ◽  
Author(s):  
Mikhail Gorchtein ◽  
Nicole F. Bell ◽  
Michael J. Ramsey-Musolf ◽  
Petr Vogel ◽  
Peng Wang
Keyword(s):  
Magnetic Moments ◽  
Majorana Neutrinos ◽  
Model Independent

Limits on the Neutrino Magnetic Moment Using Super-Kamiokande Solar Neutrino Data

2005 ◽  
Vol 20 (14) ◽  
pp. 3110-3112 ◽  
Author(s):  
◽  
D. W. Liu
Keyword(s):  
Energy Spectrum ◽  
Magnetic Moment ◽  
Solar Neutrino ◽  
New Physics ◽  
Beyond The Standard Model ◽  
High Statistic ◽  
Neutrino Magnetic Moment ◽  
The Standard Model ◽  
Neutrino Experiments ◽  
Event Rates

Existence of non-zero neutrino magnetic moment would mean new physics beyond the standard model. A search for the neutrino magnetic moment has been conducted using the high statistic solar neutrino data from Super-Kamiokande-I. This is done by looking for the distortion to the observed energy spectrum of recoil electrons. A non-zero neutrino magnetic moment would cause an increase of event rates at lower energies. The search found no clear signal of neutrino magnetic moment. A limit on the neutrino magnetic moment has been obtained at 3.6 × 10-10μB at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The effects of neutrino oscillation have been included in the analysis. Including results from other neutrino experiments limiting the oscillation region, a limit of 1.1 × 10-10μB at 90% C.L. was obtained.

scholarly journals MODEL INDEPENDENT CONSTRAINTS OF THE AVERAGED NEUTRINO MASSES REVISITED

2013 ◽  
Vol 28 (39) ◽  
pp. 1350186
Author(s):  
TAKESHI FUKUYAMA ◽  
HIROYUKI NISHIURA
Keyword(s):  
Lower Bound ◽  
Beta Decay ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Upper Bounds ◽  
Neutrino Masses ◽  
Normal Hierarchy ◽  
Inverted Hierarchy ◽  
Model Independent ◽  
Cosmological Constraint

Averaged neutrino masses defined by [Formula: see text] are reanalyzed using up-to-date observed MNS parameters and neutrino masses by the neutrino oscillation experiments together with the cosmological constraint on neutrino masses. The values of 〈mν〉ab are model-independently evaluated in terms of effective neutrino mass defined by [Formula: see text] which is observable in the single beta decay. We obtain lower bound for 〈mν〉ee in the inverted hierarchy (IH) case, 17 meV ≤〈mν〉ee and one for 〈mν〉τμ in the normal hierarchy (NH) case, 5 meV ≤〈mν〉τμ. We also obtain that all the averaged masses 〈mν〉ab have upper bounds which are at most 80 meV.

scholarly journals NEUTRINO MAGNETIC MOMENTS AND MINIMAL SUPERSYMMETRIC SO(10) MODEL

2004 ◽  
Vol 19 (28) ◽  
pp. 4825-4833 ◽  
Author(s):  
TAKESHI FUKUYAMA ◽  
TATSURU KIKUCHI ◽  
NOBUCHIKA OKADA
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Magnetic Moments ◽  
Matrix Elements ◽  
Mass Matrices ◽  
The Standard Model ◽  
Order Of Magnitude ◽  
Majorana Neutrinos ◽  
Soft Supersymmetry Breaking

We examine supersymmetric contributions to transition magnetic moments of Majorana neutrinos. We first give the general formula for it. In concrete evaluations, informations of neutrino mass matrix elements including CP phases are necessary. Using unambiguously determined neutrino mass matrices in recently proposed minimal supersymmetric SO (10) model, the transition magnetic moments are calculated. The resultant neutrino magnetic moments with the input soft supersymmetry breaking masses being of order 1 TeV are found to be roughly an order of magnitude larger than those calculated in the standard model extended to incorporate the see-saw mechanism.

scholarly journals Large neutrino magnetic moments in the light of recent experiments

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
K. S. Babu ◽  
Sudip Jana ◽  
Manfred Lindner
Keyword(s):  
Magnetic Moment ◽  
Magnetic Moments ◽  
Spin Symmetry ◽  
Simplified Model ◽  
Transition Magnetic Moment ◽  
Horizontal Symmetry ◽  
Electron Recoil ◽  
Majorana Neutrinos ◽  
The Difference ◽  
Dependent Mass

Abstract The excess in electron recoil events reported recently by the XENON1T experiment may be interpreted as evidence for a sizable transition magnetic moment $$ {\mu}_{v_e{v}_{\mu }} $$ μ v e v μ of Majorana neutrinos. We show the consistency of this scenario when a single component transition magnetic moment takes values $$ {\mu}_{v_e{v}_{\mu }}\in \left(1.65-3.42\right)\times {10}^{-11}{\mu}_B $$ μ v e v μ ∈ 1.65 − 3.42 × 10 − 11 μ B . Such a large value typically leads to unacceptably large neutrino masses. In this paper we show that new leptonic symmetries can solve this problem and demonstrate this with several examples. We first revive and then propose a simplified model based on SU(2)H horizontal symmetry. Owing to the difference in their Lorentz structures, in the SU(2)H symmetric limit, mν vanishes while $$ {\mu}_{v_e{v}_{\mu }} $$ μ v e v μ is nonzero. Our simplified model is based on an approximate SU(2)H, which we also generalize to a three family SU(3)H-symmetry. Collider and low energy tests of these models are analyzed. We have also analyzed implications of the XENON1T data for the Zee model and its extensions which naturally generate a large $$ {\mu}_{v_e{v}_{\mu }} $$ μ v e v μ with suppressed mν via a spin symmetry mechanism, but found that the induced $$ {\mu}_{v_e{v}_{\mu }} $$ μ v e v μ is not large enough to explain recent data. Finally, we suggest a mechanism to evade stringent astrophysical limits on neutrino magnetic moments arising from stellar evolution by inducing a medium-dependent mass for the neutrino.

ON PION COOLING IN THE SUPERNOVA CORE

1998 ◽  
Vol 13 (06) ◽  
pp. 915-921 ◽  
Author(s):  
SUKANTA DUTTA ◽  
ASHOK GOYAL ◽  
S. R. CHOUDHURY
Keyword(s):  
Neutron Star ◽  
Dispersion Relation ◽  
Magnetic Moment ◽  
Emission Rate ◽  
Neutrino Magnetic Moment ◽  
Pion Condensation ◽  
The Core ◽  
Cooling Mechanism ◽  
Dominant Process ◽  
Model Independent

We examine the cooling mechanism of a nascent neutron star core by the emission of wrong helicity neutrinos, when the core is at the verge of pion condensation. We study the dominant process [Formula: see text] due to neutrino magnetic moment in terms of the model-independent multipole amplitudes based on dispersion relation theory. This calculation gives a more realistic emission rate for neutrinos and hence an upper bound for neutrino magnetic moment

scholarly journals NEUTRALINO INDUCED MAJORANA NEUTRINO TRANSITION MAGNETIC MOMENTS

2009 ◽  
Vol 18 (04) ◽  
pp. 1094-1098 ◽  
Author(s):  
MAREK GÓŹDŹ ◽  
WIESŁAW A. KAMIŃSKI
Keyword(s):  
Magnetic Moment ◽  
Magnetic Moments ◽  
Majorana Neutrino ◽  
Neutrino Magnetic Moment ◽  
Order Of Magnitude

We calculate the effect of neutrino-neutralino mixing on the neutrino magnetic moment and compare it with the contribution of pure particle-sparticle loop. We have found that the dominated mechanism is still the bare loop, and that the bilinear insertions on the external neutrino lines contribute at least one order of magnitude weaker.

scholarly journals Model independent bounds on magnetic moments of Majorana neutrinos

2006 ◽  
Vol 642 (4) ◽  
pp. 377-383 ◽  
Author(s):  
Nicole F. Bell ◽  
Mikhail Gorchtein ◽  
Michael J. Ramsey-Musolf ◽  
Petr Vogel ◽  
Peng Wang
Keyword(s):  
Magnetic Moments ◽  
Majorana Neutrinos ◽  
Model Independent
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