scholarly journals Bosonic seesaw mechanism in a classically conformal extension of the Standard Model

2016 ◽  
Vol 754 ◽  
pp. 349-352 ◽  
Author(s):  
Naoyuki Haba ◽  
Hiroyuki Ishida ◽  
Nobuchika Okada ◽  
Yuya Yamaguchi
Keyword(s):  
Standard Model ◽  
Seesaw Mechanism ◽  
The Standard Model ◽  
Conformal Extension

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.

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.

INVERSE SEESAW NEUTRINO MASS FROM LEPTON TRIPLETS IN THE U(1)Σ MODEL

2009 ◽  
Vol 24 (31) ◽  
pp. 2491-2495 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
Majorana Neutrino ◽  
Neutrino Masses ◽  
Particle Interactions ◽  
Seesaw Mechanism ◽  
Type Iii ◽  
The Standard Model

The inverse seesaw mechanism of neutrino mass, i.e. [Formula: see text], where ∊L is small, is discussed in the context of the U(1)Σ model. This is a gauge extension of the Standard Model of particle interactions with lepton triplets (Σ+, Σ0, Σ-) as (Type III) seesaw anchors for obtaining small Majorana neutrino masses.

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 $\bar{B}\rightarrow X_s\gamma$ in the μνSSM

2014 ◽  
Vol 29 (38) ◽  
pp. 1450196 ◽  
Author(s):  
Hai-Bin Zhang ◽  
Guo-Hui Luo ◽  
Tai-Fu Feng ◽  
Shu-Min Zhao ◽  
Tie-Jun Gao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Rare Decay ◽  
New Physics ◽  
Majorana Neutrino ◽  
Decay Process ◽  
Neutrino Masses ◽  
Beyond The Standard Model ◽  
Seesaw Mechanism ◽  
The Standard Model

The μνSSM, one of supersymmetric extensions beyond the Standard Model, introduces three singlet right-handed neutrino superfields to solve the μ problem and can generate three tiny Majorana neutrino masses through the seesaw mechanism. In this paper, we investigate the rare decay process [Formula: see text] in the μνSSM, under a minimal flavor violating assumption for the soft breaking terms. Constrained by the SM-like Higgs with mass around 125 GeV, the numerical results show that the new physics can fit the experimental data for [Formula: see text] and further constrain the parameter space.

scholarly journals SU(2)N model of vector dark matter with a leptonic connection

2015 ◽  
Vol 30 (03) ◽  
pp. 1550018 ◽  
Author(s):  
Sean Fraser ◽  
Ernest Ma ◽  
Mohammadreza Zakeri
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cross Section ◽  
Neutrino Mass ◽  
Thermal Equilibrium ◽  
Seesaw Mechanism ◽  
The Standard Model ◽  
Relic Abundance ◽  
New Particles

Models of fermion and scalar dark matter abound. Here we consider instead vector dark matter, from an SU(2)N extension of the standard model. It has a number of interesting properties, including a possible implementation of the inverse seesaw mechanism for neutrino mass. The annihilation of dark matter for calculating its relic abundance in this model is not dominated by its cross-section to standard-model particles, but rather to other new particles which are in thermal equilibrium with those of the standard model.

scholarly journals CANONICAL SEESAW MECHANISM IN ELECTROWEAKSU(4)L⊗U(1)YMODELS

2009 ◽  
Vol 24 (32) ◽  
pp. 2589-2600 ◽  
Author(s):  
ADRIAN PALCU
Keyword(s):  
Mass Spectrum ◽  
Standard Model ◽  
Free Parameter ◽  
New Physics ◽  
Seesaw Mechanism ◽  
Gauge Models ◽  
M 10 ◽  
The Standard Model ◽  
Neutrino Mass Spectrum ◽  
Breaking Scale

In this paper we show that the canonical seesaw mechanism can naturally be implemented in a particular class of electroweak SU (4)L⊗ U (1)Ygauge models. The resulting neutrino mass spectrum is determined by just tuning a unique free parameter a within the algebraical method of treating gauge models with high symmetries proposed several years ago by Cotăescu. All the Standard Model phenomenology is preserved, being unaffected by the new physics occurring at a high breaking scale m ~ 1011GeV .

Implications of Higgs’ universality for physics beyond the Standard Model

2017 ◽  
Vol 32 (16) ◽  
pp. 1742003
Author(s):  
T. Goldman ◽  
G. J. Stephenson
Keyword(s):  
Standard Model ◽  
Sterile Neutrino ◽  
Current Data ◽  
Fermion Mass ◽  
Beyond The Standard Model ◽  
Sterile Neutrinos ◽  
Short Baseline ◽  
Seesaw Mechanism ◽  
The Standard Model ◽  
Mass Terms

We emulate Cabibbo by assuming a kind of universality for fermion mass terms in the Standard Model. We show that this is consistent with all current data and with the concept that deviations from what we term Higgs’ universality are due to corrections from currently unknown physics of nonetheless conventional form. The application to quarks is straightforward, while the application to leptons makes use of the recognition that Dark Matter can provide the “sterile” neutrinos needed for the seesaw mechanism. Requiring agreement with neutrino oscillation results leads to the prediction that the mass eigenstates of the sterile neutrinos are separated by quadratically larger ratios than for the charged fermions. Using consistency with the global fit to LSND-like, short-baseline oscillations to determine the scale of the lowest mass sterile neutrino strongly suggests that the recently observed astrophysical 3.55 keV [Formula: see text]-ray line is also consistent with the mass expected for the second most massive sterile neutrino in our analysis.

scholarly journals Neutrino Mass and the Higgs Portal Dark Matter in the ESSFSM

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Najimuddin Khan
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Neutrino Mass ◽  
Parameter Space ◽  
Direct Search ◽  
Type I ◽  
Seesaw Mechanism ◽  
The Standard Model ◽  
Relic Density ◽  
Higgs Portal

We extend the standard model with three right-handed singlet neutrinos and a real singlet scalar. We impose two Z2 and Z2′ symmetries. We explain the tiny neutrino mass-squared differences with two Z2- and Z2′-even right-handed neutrinos using type I seesaw mechanism. The Z2-odd fermion and the Z2′-odd scalar can both serve as viable dark matter candidates. We identify new regions in the parameter space which are consistent with relic density of the dark matter from recent direct search experiments LUX-2016 and XENON1T-2017 and LHC data.

Sign in / Sign up

Export Citation Format

Share Document