scholarly journals Low energy supersymmetry with baryon and lepton number gauged

2011 ◽  
Vol 84 (5) ◽  
Author(s):  
Pavel Fileviez Pérez ◽  
Mark B. Wise
Keyword(s):  
Lepton Number ◽  
Low Energy

scholarly journals Constraints on the charged currents in general neutrino interactions with sterile neutrinos

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Tong Li ◽  
Xiao-Dong Ma ◽  
Michael A. Schmidt
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Neutral Current ◽  
New Physics ◽  
Effective Field ◽  
Lepton Number ◽  
Low Energy ◽  
Electroweak Scale ◽  
Sterile Neutrinos ◽  
Neutrino Interactions

Abstract In this work we investigate the implication of low-energy precision measurements on the quark-lepton charged currents in general neutrino interactions with sterile neutrinos in effective field theories. The physics in low-energy measurements is described by the low-energy effective field theory extended with sterile neutrinos (LNEFT) defined below the electroweak scale. We also take into account renormalization group running and match the LNEFT onto the Standard Model (SM) effective field theory with sterile neutrinos (SMNEFT) to constrain new physics (NP) above the electroweak scale. The most sensitive low-energy probes are from leptonic decays of pseudoscalar mesons and hadronic tau lepton decays in terms of precise decay branching fractions, the lepton flavor universality and the Cabibbo-Kobayashi-Maskawa (CKM) unitarity. We also consider other constraints including nuclear beta decay. The constraints on charged current operators are generally stronger than the ones for quark-neutrino neutral current operators. We find that the most stringent bounds on the NP scale of lepton-number-conserving and lepton- number-violating operators in SMNEFT are 74 (110) TeV and 9.8 (13) TeV, respectively, for the operators with down (strange) quark.

scholarly journals EXPLICITLY BROKEN LEPTON NUMBER AT LOW ENERGY IN THE HIGGS TRIPLET MODEL

2006 ◽  
Vol 21 (12) ◽  
pp. 971-977 ◽  
Author(s):  
C. A. DE S. PIRES
Keyword(s):  
Mass Spectrum ◽  
Energy Scale ◽  
Lepton Number ◽  
Low Energy ◽  
Triplet Model ◽  
Scalar Sector ◽  
Higgs Triplet Model

We assume that lepton number is explicitly broken at low energy scale (M) in the framework of the Higgs triplet (Δ) model. The scalar sector of the model is developed considering the particular assumption M = vΔ ≈ eV . We show that such assumption infers a particular mass spectrum for the scalars that compose the triplet and cause a decoupling of these scalars from those that compose the standard scalar doublet.

ALTERNATIVE LOW ENERGY SUPERSYMMETRY

1990 ◽  
Vol 05 (07) ◽  
pp. 467-472 ◽  
Author(s):  
LAWRENCE J. HALL
Keyword(s):  
Baryon Number ◽  
Lepton Number ◽  
Low Energy ◽  
Additional Symmetry ◽  
Alternative Models ◽  
Gauge Symmetries

Models of low energy supersymmetry require some additional symmetry beyond the known gauge symmetries. The usual preference for R parity, which leads to the standard low energy supersymmetry model, has no clear theoretical motivation. The alternative models with minimal field content are reviewed. In one case R parity is spontaneously broken by a large sneutrino vev. In three other cases R parity is replaced by an alternative symmetry; baryon number, lepton number or ZN.

scholarly journals Operator bases in effective field theories with sterile neutrinos: d ≤ 9

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Hao-Lin Li ◽  
Zhe Ren ◽  
Ming-Lei Xiao ◽  
Jiang-Hao Yu ◽  
Yu-Hui Zheng
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Effective Field ◽  
Lepton Number ◽  
Low Energy ◽  
Field Theories ◽  
Sterile Neutrinos ◽  
Two Generations ◽  
Mass Dimension ◽  
Physical Effects

Abstract We obtain the complete and independent bases of effective operators at mass dimension 5, 6, 7, 8, 9 in both standard model effective field theory with light sterile right-handed neutrinos (νSMEFT) and low energy effective field theory with light sterile neutrinos (νLEFT). These theories provide systematical parametrizations on all possible Lorentz-invariant physical effects involving in the Majorana/Dirac neutrinos, with/without the lepton number violations. In the νSMEFT, we find that there are 2 (18), 29 (1614), 80 (4206), 323 (20400), 1358 (243944) independent operators with sterile neutrinos included at the dimension 5, 6, 7, 8, 9 for one (three) generation of fermions, while 24, 5223, 3966, 25425, 789426 independent operators in the νLEFT for two generations of up-type quarks and three generations of all other fermions.

scholarly journals Dynamical evolution of gravitational leptogenesis

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Jamie I. McDonald ◽  
Graham M. Shore
Keyword(s):  
Chemical Potential ◽  
Dynamical Evolution ◽  
Lepton Number ◽  
Low Energy ◽  
Potential Mechanism ◽  
Number Density ◽  
Tidal Effects ◽  
High Scale ◽  
Current Conservation ◽  
The Universe

Abstract Radiatively-induced gravitational leptogenesis is a potential mechanism to ex- plain the observed matter-antimatter asymmetry of the universe. Gravitational tidal effects at the quantum loop level modify the dynamics of the leptons in curved spacetime and may be encoded in a low-energy effective action Seff . It has been shown in previous work how in a high-scale BSM theory the CP odd curvature-induced interactions in Seff modify the dispersion relations of leptons and antileptons differently in an expanding universe, giving rise to an effective chemical potential and a non-vanishing equilibrium lepton-antilepton asymmetry. In this paper, the CP even curvature interactions are shown to break lepton number current conservation and modify the evolution of the lepton number density as the universe expands. These effects are implemented in a generalised Boltzmann equation and used to trace the dynamical evolution of the lepton number density in different cosmological scenarios. The theory predicts a potentially significant gravitationally-induced lepton-antilepton asymmetry at very early times in the evolution of the universe.

scholarly journals A Froggatt–Nielsen flavor model for neutrino physics

2019 ◽  
Vol 34 (19) ◽  
pp. 1950102 ◽  
Author(s):  
Micheal S. Berger ◽  
Maria Dawid
Keyword(s):  
Neutrino Physics ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Lepton Number ◽  
Double Beta Decay ◽  
Low Energy ◽  
Lepton Number Violation ◽  
Flavor Violation

Superheavy neutrinos can, via the seesaw model, provide a mechanism for lepton number violation. If they are combined with flavor violation as characterized by the Froggatt–Nielsen mechanism, then the phenomenology for the neutrinos in oscillation experiments, neutrinoless double beta decay, and other experiments can be described by a relatively few number of parameters. We describe the low-energy neutrino mass matrix and show that the results are consistent with currently available data.

scholarly journals Low energy effective field theory operator basis at d ≤ 9

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Hao-Lin Li ◽  
Zhe Ren ◽  
Ming-Lei Xiao ◽  
Jiang-Hao Yu ◽  
Yu-Hui Zheng
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Equation Of Motion ◽  
Effective Field ◽  
Lepton Number ◽  
Low Energy ◽  
Electroweak Scale ◽  
Integration By Parts ◽  
Motion Integration ◽  
Theory Operator

Abstract We obtain the complete operator bases at mass dimensions 5, 6, 7, 8, 9 for the low energy effective field theory (LEFT), which parametrize various physics effects between the QCD scale and the electroweak scale. The independence of the operator basis regarding the equation of motion, integration by parts and flavor relations, is guaranteed by our algorithm [1, 2], whose validity for the LEFT with massive fermions involved is proved by a generalization of the amplitude-operator correspondence. At dimension 8 and 9, we list the 35058 (756) and 704584 (3686) operators for three (one) generations of fermions categorized by their baryon and lepton number violations (∆B, ∆L), as these operators are of most phenomenological relevance.

scholarly journals Phenomenology of the neutrino-mass-giving Higgs triplet and the low-energy seesaw violation of lepton number

2001 ◽  
Vol 615 (1-3) ◽  
pp. 313-330 ◽  
Author(s):  
Ernest Ma ◽  
Martti Raidal ◽  
Utpal Sarkar
Keyword(s):  
Neutrino Mass ◽  
Lepton Number ◽  
Low Energy

Dissociated Σ=27 boundaries in silicon

1988 ◽  
Vol 46 ◽  
pp. 624-625
Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth
Keyword(s):  
Electron Diffraction ◽  
Local Minimum ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Boundary Plane ◽  
Low Energy ◽  
Theoretical Understanding ◽  
Site Lattice ◽  
Kikuchi Pattern ◽  
Analysis Techniques

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.

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