scholarly journals Neutrino mass generation with extra right-handed fields in a Dirac scenario via the type-I seesaw mechanism

2014 ◽  
Vol 29 (40) ◽  
pp. 1450212 ◽  
Author(s):  
Ernesto A. Matute
Keyword(s):  
Small Mass ◽  
Type I ◽  
High Scale ◽  
Mass Generation ◽  
Seesaw Mechanism ◽  
Scale Type ◽  
Left Handed ◽  
Natural Choice ◽  
The Standard Model ◽  
Neutrino Mass Generation

An extension of the Standard Model (SM) is studied in which two right-handed (RH) neutrinos per generation are incorporated, but considering the hypothesis of the symmetry of lepton and quark contents in order to deprive the number of RH neutrinos of freedom, generate Dirac neutrinos and accommodate naturally tiny values for their masses. The high scale type-I seesaw regime is applied to the first, ordinary RH neutrino, whereas a low scale pseudo-Dirac scenario is used for the second, adulterant RH neutrino, implying that the first RH neutrino decouples at the high scale, while the second RH neutrino survives down to the low scale to pair off in a Dirac-like form with the corresponding left-handed (LH) neutrino. The small mass and couplings of this extra RH neutrino are explained by means of the statement of the symmetry of fermionic content, only regarded as a guideline to the natural choice of parameters since it is not a proper symmetry in the Lagrangian.

scholarly journals Natural Higgs inflation, gauge coupling unification, and neutrino masses

2020 ◽  
Vol 35 (21) ◽  
pp. 2050117
Author(s):  
Heng-Yu Chen ◽  
Ilia Gogoladze ◽  
Shan Hu ◽  
Tianjun Li ◽  
Lina Wu
Keyword(s):  
Top Quark ◽  
Gauge Coupling ◽  
Neutrino Masses ◽  
Type I ◽  
Mass Generation ◽  
Vacuum Stability ◽  
Seesaw Mechanism ◽  
Quark Masses ◽  
The Standard Model ◽  
Neutrino Mass Generation

We present a class of nonsupersymmetric models in which the so-called critical Higgs inflation [Formula: see text] can be naturally realized without using specific values for Higgs and top quark masses. In these scenarios, the Standard Model (SM) vacuum stability problem, gauge coupling unification, neutrino mass generation and Higgs inflation mechanism are linked to each other. We adopt in our models Type I seesaw mechanism for neutrino masses. An appropriate choice of the Type I seesaw scale allows us to have an arbitrarily small but positive value of SM Higgs quartic coupling around the inflation scale. We present a few benchmark points where we show that the scalar spectral indices are around 0.9626 and 0.9685 for the number of [Formula: see text]-folding [Formula: see text] and [Formula: see text], respectively. The tensor-to-scalar ratios are of the order of [Formula: see text]. The running of the scalar spectral index is negative and is of the order of [Formula: see text].

scholarly journals MODEL FOR SMALL NEUTRINO MASSES AT THE TeV SCALE

2002 ◽  
Vol 17 (13) ◽  
pp. 771-778 ◽  
Author(s):  
SALAH NASRI ◽  
SHERIF MOUSSA
Keyword(s):  
Standard Model ◽  
Majorana Neutrino ◽  
Lepton Number ◽  
Neutrino Masses ◽  
Mass Generation ◽  
Seesaw Mechanism ◽  
Left Handed ◽  
The Standard Model ◽  
Neutrino Mass Generation ◽  
The One

We propose a model for neutrino mass generation in which no physics beyond a TeV is required. We extend the standard model by adding two charged singlet fields with lepton number two. Dirac neutrino masses mνD ≤ MeV are generated at the one-loop level. Small left-handed Majorana neutrino masses can be generated via the seesaw mechanism with right-handed neutrino masses MR of order TeV scale.

scholarly journals Investigating two heavy neutral leptons neutrino seesaw mechanism at SHiP

2019 ◽  
Vol 34 (08) ◽  
pp. 1950047
Author(s):  
Marco Chianese ◽  
Damiano F. G. Fiorillo ◽  
Gennaro Miele ◽  
Stefano Morisi
Keyword(s):  
Neutrino Mass ◽  
Double Beta Decay ◽  
Type I ◽  
Mass Generation ◽  
Seesaw Mechanism ◽  
Mixing Angle ◽  
Mechanism Model ◽  
Neutrino Mass Generation ◽  
Generation Mechanisms ◽  
The Masses

One of the main purposes of SHiP experiment is to shed light on neutrino mass generation mechanisms like the so-called seesaw. We consider a minimal type-I seesaw neutrino mass mechanism model with two heavy neutral leptons (right-handed or sterile neutrinos) with arbitrary masses. Extremely high active-sterile mixing angle requires a correlation between the phases of the Dirac neutrino couplings. Actual experimental limits on the half-life of neutrinoless double beta decay [Formula: see text]-rate on the active-sterile mixing angle are not significative in constraining the masses or the mixing measurable by SHiP.

scholarly journals Neutrino mass generation from the perspective of presymmetry

2019 ◽  
Vol 34 (34) ◽  
pp. 1950284
Author(s):  
Ernesto A. Matute
Keyword(s):  
Topological Charge ◽  
Mass Splitting ◽  
High Scale ◽  
Sterile Neutrinos ◽  
Mass Generation ◽  
The Standard Model ◽  
Induced Charge ◽  
Neutrino Mass Generation ◽  
Gauge Anomalies ◽  
Topological Charges

The Standard Model (SM) with one right-handed neutrino per generation is revisited with presymmetry being the global [Formula: see text] symmetry of an electroweak theory of leptons and quarks with initially postulated symmetric fractional charges. The cancellation of gauge anomalies and the non-perturbative normalization of lepton charges proceed through the mixing of local and topological charges, the global [Formula: see text] measuring the induced charge associated with a unit of topological charge, and the mathematical replacement of the original fractional charges with the experimentally observed ones. The [Formula: see text] symmetry of the SM with Dirac neutrinos is seen as a residual presymmetry. High-scale and low-scale seesaw mechanisms proposed to explain the mass of neutrinos are examined from the perspective of presymmetry, be they of Majorana or pseudo-Dirac type. We find that the tiny mass splitting in pseudo-Dirac neutrinos and the mass of heavy neutrinos ride on the opposite ends of the seesaw. We show that pseudo-Dirac neutrinos contain extra sterile neutrinos with imprints of presymmetry and for heavy ones we get constraints favoring the low-scale linear seesaw over the inverse variant.

scholarly journals Presymmetry in the Standard Model with adulterated Dirac neutrinos

2015 ◽  
Vol 30 (31) ◽  
pp. 1550160 ◽  
Author(s):  
Ernesto A. Matute
Keyword(s):  
Standard Model ◽  
High Energy ◽  
New Physics ◽  
Boson Mass ◽  
Effective Theory ◽  
Type I ◽  
Electroweak Symmetry ◽  
Seesaw Mechanism ◽  
Left Handed ◽  
The Standard Model

Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the ’t Hooft’s naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.

scholarly journals Extraction of neutrino Yukawa parameters from displaced vertices of sneutrinos

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Amit Chakraborty ◽  
Stefano Moretti ◽  
Claire H. Shepherd-Themistocleous ◽  
Harri Waltari
Keyword(s):  
Large Hadron Collider ◽  
Hadron Collider ◽  
Underlying Mechanism ◽  
Type I ◽  
High Luminosity ◽  
Mass Generation ◽  
Seesaw Mechanism ◽  
Neutrino Mass Generation ◽  
Charged Leptons ◽  
Higgs Portal

Abstract We study displaced signatures of sneutrino pairs potentially emerging at the Large Hadron Collider (LHC) in a Next-to-Minimal Supersymmetric Standard Model supplemented with right-handed neutrinos triggering a Type-I seesaw mechanism. We show how such signatures can be established through a heavy Higgs portal, the sneutrinos then decaying to charged leptons and charginos giving rise to further leptons or hadrons. We finally illustrate how the Yukawa parameters of neutrinos can be extracted by measuring the lifetime of the sneutrino from the displaced vertices, thereby characterising the dynamics of the underlying mechanism of neutrino mass generation. We show our numerical results for the case of both the current and High-Luminosity LHC.

scholarly journals Consistency of the dynamical high-scale type-I seesaw mechanism

2020 ◽  
Vol 101 (11) ◽  
Author(s):  
Sanjoy Mandal ◽  
Rahul Srivastava ◽  
José W. F. Valle
Keyword(s):  
Type I ◽  
High Scale ◽  
Seesaw Mechanism ◽  
Scale Type

scholarly journals The Nature of Massive Neutrinos

2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
S. T. Petcov
Keyword(s):  
Neutrino Mass ◽  
Current Data ◽  
Future Research ◽  
Type I ◽  
Neutrino Mixing ◽  
Mass Generation ◽  
Triplet Model ◽  
Majorana Neutrinos ◽  
Massive Neutrinos ◽  
Neutrino Mass Generation

The compelling experimental evidences for oscillations of solar, reactor, atmospheric, and accelerator neutrinos imply the existence of 3-neutrino mixing in the weak charged lepton current. The current data on the 3-neutrino mixing parameters are summarised and the phenomenology of 3-νmixing is reviewed. The properties of massive Majorana neutrinos and of their various possible couplings are discussed in detail. Two models of neutrino mass generation with massive Majorana neutrinos—the type I see-saw and the Higgs triplet model—are briefly reviewed. The problem of determining the nature, Dirac or Majorana, of massive neutrinos is considered. The predictions for the effective Majorana mass|〈m〉|in neutrinoless double-beta-((ββ)0ν-) decay in the case of 3-neutrino mixing and massive Majorana neutrinos are summarised. The physics potential of the experiments, searching for(ββ)0ν-decay for providing information on the type of the neutrino mass spectrum, on the absolute scale of neutrino masses, and on the Majorana CP-violation phases in the PMNS neutrino mixing matrix, is also briefly discussed. The opened questions and the main goals of future research in the field of neutrino physics are outlined.

scholarly journals Flipped U(1) extended standard model and Majorana dark matter

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Cao H. Nam
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Boson Mass ◽  
Type I ◽  
Seesaw Mechanism ◽  
Gauge Symmetries ◽  
The Standard Model ◽  
Gauge Boson Mass ◽  
The Right ◽  
Relic Abundance

AbstractWe propose a general flavor-independent extension of the Standard Model (SM) with the minimal particle content, based on the symmetry $$SU(3)_C\times SU(2)_L\times U(1)_{Y'}\times U(1)_X\times Z_2$$ S U ( 3 ) C × S U ( 2 ) L × U ( 1 ) Y ′ × U ( 1 ) X × Z 2 . In this scenario, the charge operator is identified in terms of the charges of two U(1) gauge symmetries. The light neutrino masses are generated via Type-I seesaw mechanism only with two heavy right-handed neutrinos acquiring their Majorana masses through the $$U(1)_{Y'}\times U(1)_X$$ U ( 1 ) Y ′ × U ( 1 ) X symmetry breaking. We study various experimental constraints on the parameters of the model and investigate the phenomenology of the right-handed neutrino dark matter (DM) candidate assigned a $$Z_2$$ Z 2 -odd parity. We find that the most important constraints are the observed DM relic abundance, the current LHC limits, and the ambiguity of the SM neutral gauge boson mass.

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