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 HIDING THE EXISTENCE OF A FAMILY SYMMETRY IN THE STANDARD MODEL

2005 ◽  
Vol 20 (36) ◽  
pp. 2767-2774 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Neutrino Mass Matrix ◽  
Tree Level ◽  
Family Symmetry ◽  
The Standard Model

If a family symmetry exists for the quarks and leptons, the Higgs sector is expected to be enlarged to be able to support the transformation properties of this symmetry. There are, however, three possible generic ways (at tree level) of hiding this symmetry in the context of the Standard Model with just one Higgs doublet. All three mechanisms have their natural realizations in the unification symmetry E6 and one in SO (10). An interesting example based on SO (10)×A4 for the neutrino mass matrix is discussed.

scholarly journals ON THE FORMULATION OF THE GENERIC SUPERSYMMETRIC STANDARD MODEL (OR SUPERSYMMETRY WITHOUT R PARITY)

2004 ◽  
Vol 19 (12) ◽  
pp. 1863-1892 ◽  
Author(s):  
OTTO C. W. KONG
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Ad Hoc ◽  
Discrete Symmetry ◽  
Tree Level ◽  
Gauge Symmetries ◽  
Supersymmetric Version ◽  
Mass Matrices ◽  
The Standard Model ◽  
Soft Supersymmetry Breaking

The generic supersymmetric version of the Standard Model would have the minimal list of superfields incorporating the Standard Model particles, and a Lagrangian dictated by the Standard Model gauge symmetries. To be phenomenologically viable, soft supersymmetry breaking terms have to be included. In the most popular version of the supersymmetric Standard Model, an ad hoc discrete symmetry, called R parity, is added in by hand. While there has been a lot of various kinds of R-parity violation studies in the literature, the complete version of supersymmetry without R parity is not popularly appreciated. In this article, we present a pedagogical review of the formulation of this generic supersymmetric Standard Model and give a detailed discussion on the basic conceptual issues involved. Unfortunately, there are quite some confusing, or even plainly wrong, statements on the issues within the literature of R-parity violations. We aim at clarifying these issues here. We will first discuss our formulation, about which readers are urged to read without bias from previous acquired perspectives on the topic. Based on the formulation, we will then address the various issues. In relation to phenomenology, our review here will not go beyond tree-level mass matrices. But we will give a careful discussion of mass matrices of all the matter fields involved. Useful expressions for perturbative diagonalizations of the mass matrices at the phenomenologically interesting limit of corresponds to small neutrino masses are derived. All these expressions are given in the fully generic setting, with information on complex phases of parameters retained. Such expressions have been shown to be useful in the analyses of various phenomenological features.

scholarly journals QUARK MASS MATRICES AND OBSERVABLE QUANTITIES

1999 ◽  
Vol 14 (29) ◽  
pp. 1989-2001 ◽  
Author(s):  
D. FALCONE
Keyword(s):  
Standard Model ◽  
Matrix Models ◽  
Quark Mass ◽  
Mass Matrix ◽  
Historical Account ◽  
A Value ◽  
Mass Matrices ◽  
The Standard Model

A nearly historical account of quark mass matrix models is given, and the structure of quark mass matrices in the standard model is studied. For a minimal parameter basis suggested earlier, where Mu is diagonal and Md11, Md13, Md31 are zero, the dependence of mass matrices on the CP violating phase δ of V CKM is reported: all parameters are almost independent, except Md22 and Md23, and the equality |Md22| = Md23 is obtained for a value of δ very close to the value which is favored by experiments. Moreover, on this basis, Md12≃Md21 and Md33≃2Md32. Some comments on mass matrices in left–right symmetric models are added.

scholarly journals Towards an Improved Test of the Standard Model’s Most Precise Prediction

Atoms ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 45 ◽  
Author(s):  
G. Gabrielse ◽  
S. Fayer ◽  
T. Myers ◽  
X. Fan
Keyword(s):  
Elementary Particle ◽  
Standard Model ◽  
Experimental Method ◽  
Particle Physics ◽  
Measurement Accuracy ◽  
Magnetic Moments ◽  
The Standard Model ◽  
Order Of Magnitude ◽  
Precise Prediction

The electron and positron magnetic moments are the most precise prediction of the standard model of particle physics. The most accurate measurement of a property of an elementary particle has been made to test this result. A new experimental method is now being employed in an attempt to improve the measurement accuracy by an order of magnitude. Positrons from a “student source” now suffice for the experiment. Progress toward a new measurement is summarized.

scholarly journals Parity and the origin of neutrino mass

2020 ◽  
Vol 35 (09) ◽  
pp. 2050053
Author(s):  
Goran Senjanović ◽  
Vladimir Tello
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Spontaneous Breaking ◽  
Symmetric Model ◽  
Hadron Colliders ◽  
Seesaw Mechanism ◽  
Fermion Masses ◽  
Mass Matrices ◽  
The Standard Model ◽  
Complete Analogy

In the LHC era the issue of the origin and nature of neutrino mass has attained a new meaning and a renewed importance. The growing success of the Higgs–Weinberg mechanism behind the charged fermion masses paves the way for answering the question of neutrino mass. We have shown recently how the spontaneous breaking of parity in the context of the minimal left–right symmetric model allows to probe the origin of neutrino mass in complete analogy with the charged fermions masses in the Standard Model. We revisit here this issue and fill in the gaps left in our previous work. In particular we discuss a number of different mathematical approaches to the problem of disentangling the seesaw mechanism and show how a unique analytical solution emerges. Most important, we give all the possible expressions for the neutrino Dirac mass matrix for general values of light and heavy neutrino mass matrices. In practical terms what is achieved is an untangling of the seesaw mechanism with clear and precise predictions testable at hadron colliders such as LHC.

scholarly journals FERMION MASSES AND MIXINGS IN GAUGE THEORIES

2002 ◽  
Vol 17 (28) ◽  
pp. 3981-4006 ◽  
Author(s):  
D. FALCONE
Keyword(s):  
Gauge Symmetry ◽  
Standard Model ◽  
Neutrino Mass ◽  
Quark Mass ◽  
Gauge Theories ◽  
Neutrino Oscillations ◽  
Heavy Neutrino ◽  
Fermion Masses ◽  
Mass Matrices ◽  
The Standard Model

The recent evidence for neutrino oscillations stimulate us to discuss again the problem of fermion masses and mixings in gauge theories. In the standard model, several forms for quark mass matrices are equivalent. They become ansatze within most extensions of the standard model, where also relations between quark and lepton sectors may hold. In a seesaw framework, these relations can constrain the scale of heavy neutrino mass, which is often related to the scale of intermediate or unification gauge symmetry. As a consequence, two main scenarios arise. Hierarchies of masses and mixings may be explained by broken horizontal symmetries.

scholarly journals NEUTRINO PHYSICS: OPEN THEORETICAL QUESTIONS

2004 ◽  
Vol 19 (08) ◽  
pp. 1180-1197 ◽  
Author(s):  
A. Y. SMIRNOV
Keyword(s):  
Neutrino Physics ◽  
Standard Model ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
New Physics ◽  
Present Knowledge ◽  
Beyond The Standard Model ◽  
Neutrino Mass And Mixing ◽  
Open Questions ◽  
The Standard Model

We know that neutrino mass and mixing provide a window to physics beyond the Standard Model. Now this window is open, at least partly. And the questions are: what do we see, which kind of new physics, and how far "beyond"? I summarize the present knowledge of neutrino mass and mixing, and then formulate the main open questions. Following the bottom-up approach, properties of the neutrino mass matrix are considered. Then different possible ways to uncover the underlying physics are discussed. Some results along the line of seesaw, GUT and SUSY GUT are reviewed.

scholarly journals LEPTON FAMILY SYMMETRY AND NEUTRINO MASS MATRIX

2004 ◽  
Vol 19 (08) ◽  
pp. 577-582 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
Solar Neutrino ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Diagonal Form ◽  
Family Symmetry ◽  
The Standard Model ◽  
Lepton Family

The standard model of leptons is extended to accommodate a discrete Z3×Z2 family symmetry. After rotating the charged-lepton mass matrix to its diagonal form, the neutrino mass matrix reveals itself as very suitable for explaining atmospheric and solar neutrino oscillation data. A generic requirement of this approach is the appearance of three Higgs doublets at the electroweak scale, with observable flavor violating decays.

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