scholarly journals Quasi-Dirac neutrinos in the linear seesaw model

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Carolina Arbeláez ◽  
Claudio Dib ◽  
Kevin Monsálvez-Pozo ◽  
Iván Schmidt
Keyword(s):  
Neutrino Mass ◽  
Upper Bound ◽  
Opposite Sign ◽  
Mass Splitting ◽  
Light Neutrino ◽  
Experimental Measurements ◽  
Neutrino Masses ◽  
Seesaw Model ◽  
Light Neutrino Mass ◽  
Displaced Vertex

Abstract We implement a minimal linear seesaw model (LSM) for addressing the Quasi-Dirac (QD) behaviour of heavy neutrinos, focusing on the mass regime of MN ≲ MW. Here we show that for relatively low neutrino masses, covering the few GeV range, the same-sign to opposite-sign dilepton ratio, Rℓℓ, can be anywhere between 0 and 1, thus signaling a Quasi-Dirac regime. Particular values of Rℓℓ are controlled by the width of the QD neutrino and its mass splitting, the latter being equal to the light-neutrino mass mν in the LSM scenario. The current upper bound on mν1 together with the projected sensitivities of current and future |UN ℓ|2 experimental measurements, set stringent constraints on our low-scale QD mass regime. Some experimental prospects of testing the model by LHC displaced vertex searches are also discussed.

NEUTRINO MASSES WITH DYNAMICAL ELECTROWEAK SYMMETRY BREAKING

2003 ◽  
Vol 18 (22) ◽  
pp. 3935-3946 ◽  
Author(s):  
THOMAS APPELQUIST
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Electroweak Symmetry Breaking ◽  
Light Neutrino ◽  
Neutrino Masses ◽  
Electroweak Symmetry ◽  
Explicit Model ◽  
Dirac Neutrino ◽  
Mass Terms

In this talk I discuss the problem of accounting for light neutrino masses in theories with dynamical electroweak symmetry breaking. I will first describe this problem generally in a class of extended technicolor (ETC) models, describing the full set of Dirac and Majorana masses that arise in such theories. I will then present an explicit model exhibiting a combination of suppressed Dirac masses and a seesaw involving dynamically generated condensates of standard-model singlet, ETC-nonsinglet fermions. Because of the suppression of the Dirac neutrino mass terms, a seesaw yielding realistic neutrino masses does not require superheavy Majorana masses; indeed, the Majorana masses are typically much smaller than the largest ETC scale.

NEUTRINO MASSES AND TeV SCALE RESONANT LEPTOGENESIS FROM SUPERSYMMETRY BREAKING

2006 ◽  
Vol 21 (21) ◽  
pp. 1629-1646 ◽  
Author(s):  
STEPHEN M. WEST
Keyword(s):  
Supersymmetry Breaking ◽  
Mass Matrix ◽  
Mass Splitting ◽  
Light Neutrino ◽  
Tree Level ◽  
Neutrino Masses ◽  
Yukawa Couplings ◽  
Neutrino Sector ◽  
The One ◽  
The Right

We review a class of supersymmetric models in which the light neutrino masses result from higher-dimensional supersymmetry-breaking terms in the MSSM super- and Kähler-potentials. The mechanism used in these models is closely related to the Giudice–Masiero mechanism for the MSSM μ parameter and leads to TeV-scale right-handed neutrino and sneutrino states. In these models, the dominant contribution to the light neutrino (Majorana) mass matrix is a one-loop term with a sub-dominant tree-level "seesaw" contribution. It is also shown that it is possible to construct a natural model of TeV-scale leptogenesis via the resonant behavior of the one-loop self-energy contribution to the right-handed neutrino (Ni) decay. This model addresses the primary problems of previous phenomenological studies of low-energy leptogenesis: a rational for TeV-scale right-handed neutrinos with small Yukawa couplings; the origin of the tiny, but non-zero mass splitting required between at least two Ni masses; and the necessary non-trivial breaking of flavor symmetries in the right-handed neutrino sector.

scholarly journals Leptogenesis in supersymmetry with one L violating coupling

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Rathin Adhikari ◽  
Arnab Dasgupta
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Neutrino Mass ◽  
Feynman Diagram ◽  
Light Neutrino ◽  
Majorana Phase ◽  
Light Neutrino Mass

AbstractWe have shown a new scenario of successful leptogenesis with one L violating coupling and a relative Majorana phase playing the role of CP violation. This is in contrast to the usual consideration of Feynman diagram with at least two L violating couplings. We have considered R-parity violating minimal supersymmetric standard model (MSSM) for leptogenesis at TeV scale. This scenario is also consistent with generating light neutrino mass if asymmetry is generated through semileptonic $$\lambda ^{\prime }$$ λ ′ coupling.

scholarly journals UPPER BOUND ON THE SCALE OF MAJORANA-NEUTRINO MASS GENERATION

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 709-711 ◽  
Author(s):  
J. M. NICZYPORUK
Keyword(s):  
Neutrino Mass ◽  
Upper Bound ◽  
Planck Scale ◽  
Majorana Neutrino ◽  
Grand Unification ◽  
Neutrino Masses ◽  
Mass Generation ◽  
Model Independent ◽  
Neutrino Mass Generation ◽  
Majorana Neutrino Mass

We derive a model-independent upper bound on the scale of Majorana-neutrino mass generation. The upper bound is [Formula: see text], where v ≃246 GeV is the weak scale and mν is the Majorana-neutrino mass. For neutrino masses implied by neutrino oscillation experiments, all but one of these bounds are less than the Planck scale, and they are all within a few orders of magnitude of the grand-unification scale.

scholarly journals Inelastic fermion dark matter origin of XENON1T excess with muon (g − 2) and light neutrino mass

2020 ◽  
Vol 811 ◽  
pp. 135933 ◽  
Author(s):  
Debasish Borah ◽  
Satyabrata Mahapatra ◽  
Dibyendu Nanda ◽  
Narendra Sahu
Keyword(s):  
Dark Matter ◽  
Neutrino Mass ◽  
Light Neutrino ◽  
Light Neutrino Mass

scholarly journals Neutrino mass models: new classification and model-independent upper limits on their scale

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Juan Herrero-García ◽  
Michael A. Schmidt
Keyword(s):  
Neutrino Mass ◽  
Upper Bound ◽  
Effective Field ◽  
Lepton Number ◽  
Neutrino Masses ◽  
Beyond The Standard Model ◽  
Upper Limits ◽  
The Standard Model ◽  
Model Independent ◽  
Neutrino Mass Models

AbstractWe propose a model-independent framework to classify and study neutrino mass models and their phenomenology. The idea is to introduce one particle beyond the Standard Model which couples to leptons and carries lepton number together with an operator which violates lepton number by two units and contains this particle. This allows to study processes which do not violate lepton number, while still working with an effective field theory. The contribution to neutrino masses translates to a robust upper bound on the mass of the new particle. We compare it to the stronger but less robust upper bound from Higgs naturalness and discuss several lower bounds. Our framework allows to classify neutrino mass models in just 20 categories, further reduced to 14 once nucleon decay limits are taken into account, and possibly to 9 if also Higgs naturalness considerations and direct searches are considered.

scholarly journals A FRAMEWORK TO SIMULTANEOUSLY EXPLAIN TINY NEUTRINO MASS AND HUGE MISSING MASS PROBLEM OF THE UNIVERSE

2010 ◽  
Vol 25 (25) ◽  
pp. 2111-2120 ◽  
Author(s):  
YASAMAN FARZAN
Keyword(s):  
Dark Matter ◽  
Lower Bound ◽  
Neutrino Mass ◽  
Upper Bound ◽  
Low Energy ◽  
Neutrino Masses ◽  
Energy Scenario ◽  
The Masses ◽  
The Universe

A minimalistic scenario is developed to explain dark matter and tiny but nonzero neutrino masses. A new scalar called SLIM plays the role of the dark matter. Neutrinos achieve Majorana mass through a one-loop diagram. This scenario can be realized for both real and complex SLIM. Simultaneously explaining the neutrino mass and dark matter abundance constrains the scenario. In particular for real SLIM, an upper bound of a few MeV on the masses of the new particles and a lower bound on their coupling is obtained which make the scenario testable. The low energy scenario can be embedded within various SU (2)× U (1) symmetric models. A specific example is introduced and its phenomenological consequences are discussed.

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