scholarly journals Standard-Model Coupling Constants from Compositeness

2003 ◽  
Vol 18 (27) ◽  
pp. 1877-1885 ◽  
Author(s):  
J. Besprosvany
Keyword(s):  
Standard Model ◽  
Particle Interaction ◽  
Coupling Constants ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Coupling Constant ◽  
The Standard Model ◽  
Standard Model Coupling ◽  
Breaking Scale ◽  
Vector Particles

A coupling-constant definition is given based on the compositeness property of some particle states with respect to the elementary states of other particles. It is applied in the context of the vector-spin-1/2-particle interaction vertices of a field theory, and the standard model. The definition reproduces Weinberg's angle in a grand-unified theory. One obtains coupling values close to the experimental ones for appropriate configurations of the standard-model vector particles, at the unification scale within grand-unified models, and at the electroweak breaking scale.

A Clifford algebra-based grand unification program of gravity and the Standard Model: a review study

2014 ◽  
Vol 92 (12) ◽  
pp. 1501-1527 ◽  
Author(s):  
Carlos Castro
Keyword(s):  
Standard Model ◽  
Geometric Probability ◽  
Coupling Constants ◽  
Grand Unified Theory ◽  
Neutrino Mixing ◽  
Yang Mills ◽  
Bounded Complex ◽  
The Standard Model ◽  
Mixing Matrix ◽  
Homogeneous Domains

A Clifford Cl(5, C) unified gauge field theory formulation of conformal gravity and U(4) × U(4) × U(4) Yang–Mills in 4D, is reviewed along with its implications for the Pati–Salam (PS) group SU(4) × SU(2)L × SU(2)R, and trinification grand unified theory models of three fermion generations based on the group SU(3)C × SU(3)L × SU(3)R. We proceed with a brief review of a unification program of 4D gravity and SU(3) × SU(2) × U(1) Yang–Mills emerging from 8D pure quaternionic gravity. A realization of E8 in terms of the Cl(16) = Cl(8) ⊗ Cl(8) generators follows, as a preamble to F. Smith’s E8 and Cl(16) = Cl(8) ⊗ Cl(8) unification model in 8D. The study of chiral fermions and instanton backgrounds in CP2 and CP3 related to the problem of obtaining three fermion generations is thoroughly studied. We continue with the evaluation of the coupling constants and particle masses based on the geometry of bounded complex homogeneous domains and geometric probability theory. An analysis of neutrino masses, Cabbibo–Kobayashi–Maskawa quark-mixing matrix parameters, and neutrino-mixing matrix parameters follows. We finalize with some concluding remarks about other proposals for the unification of gravity and the Standard Model, like string, M, and F theories and noncommutative and nonassociative geometry.

A DETAILED ACCOUNT OF ALAIN CONNES' VERSION OF THE STANDARD MODEL IN NON-COMMUTATIVE GEOMETRY: I AND II.

1993 ◽  
Vol 05 (03) ◽  
pp. 477-532 ◽  
Author(s):  
DANIEL KASTLER
Keyword(s):  
Standard Model ◽  
Coupling Constants ◽  
Fermion Mass ◽  
Detailed Calculation ◽  
Coupling Constant ◽  
Electroweak Interactions ◽  
Symmetrical Form ◽  
Mass Matrices ◽  
The Standard Model ◽  
Universal Coupling

We present a detailed calculation of the Lagrangian of the standard model prescribed in the paper [4] of Connes and Lott, first for the electroweak interactions alone, and then (as is necessary to achieve the correct weak hypercharge assignments) for the coupling of electroweak interactions with chromodynamics. In its most symmetrical form (with free parameters the fermion mass-matrices plus one universal coupling constant), the Connes theory in tree-approximation yields equality of the strong and electroweak coupling constants, and fixes the value sin 2 θw = 3/8, and the ratios mt/mw and mH/mt.

scholarly journals W-boson production in the high energy electron-photon collisions

2019 ◽  
pp. 41-50
Author(s):  
Ivan A. Shershan ◽  
Tatiana V. Shishkina
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
W Boson ◽  
High Energy ◽  
New Physics ◽  
Coupling Constants ◽  
Boson Production ◽  
The Standard Model ◽  
Electron Photon ◽  
W Boson Production

In this paper the analysis of W-boson production process in high-energy electron-photon collisions as a tool to search for deviations from the Standard Model is considered. In particular, a set of extended gauge models, including anomalous multi-boson interactions, are discussed as a promising way for «new physics» study. A numerical analysis of the total cross sections of the processes was carried out. The lowest order radiative corrections in the soft-photon approximation within the Standard Model are taken into account. Calculations beyond the Standard Model was performed, the kinematic features of the cross sections were identified. The restrictions on the anomalous triple gauge boson coupling constants were analyzed and the kinematic areas to the search for their manifestations were obtained during the experiments at the International Linear Collider. The paper shows that the search for «new physics» effects based on electron-photon collisions around the W-boson production peak is the maximal promising. It was also shown that future experiments at high luminosity linear colliders will significantly clarify the constraints on anomalous gauge coupling constants.

scholarly journals Rb, Rc and New Physics: An Updated Model Independent Analysis

1997 ◽  
Vol 12 (04) ◽  
pp. 723-742 ◽  
Author(s):  
P. Bamert
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
New Physics ◽  
Low Energy ◽  
Coupling Constant ◽  
A Value ◽  
Independent Analysis ◽  
The Standard Model ◽  
Necessary And Sufficient ◽  
Do So

We analyze LEP and SLC data from the 1995 Summer Conferences as well as from low energy neutral current experiments for signals of new physics. The reasons for doing this are twofold: first to explain the deviations from the Standard Model observed in Rb and Rc and second to constrain nonstandard contributions to couplings of the Z0 boson to all fermions and to the oblique parameters. We do so by comparing the data with the Standard Model as well as with a number of test hypotheses concerning the nature of the new physics. These include nonstandard [Formula: see text]-, [Formula: see text]- and [Formula: see text]-couplings as well as the couplings of the Z0 to fermions of the entire first, second and third generations and universal corrections to all up- and down-type quark couplings (as can arise see for example in Z' mixing models). We find that nonstandard [Formula: see text] couplings are both necessary and sufficient to explain the data and in particular the Rb anomaly. It is not possible to explain Rb, Rc and a value of the strong coupling constant consistent with low energy determinations invoking only nonstandard [Formula: see text]- and [Formula: see text]-couplings. To do so one has to have also new physics contributions to the [Formula: see text] or universal corrections to all [Formula: see text] couplings.

scholarly journals Sub-GeV-scale signatures of hidden braneworlds up to the Planck scale in a SO(3,1)-broken bulk

2019 ◽  
Vol 34 (05) ◽  
pp. 1950029 ◽  
Author(s):  
Coraline Stasser ◽  
Michaël Sarrazin
Keyword(s):  
Standard Model ◽  
Phenomenological Model ◽  
Quantum Dynamics ◽  
Scale Up ◽  
Planck Scale ◽  
Energy Scale ◽  
Beyond The Standard Model ◽  
Coupling Constant ◽  
The Standard Model ◽  
Gut Scale

Many-brane Universes are at the heart of several cosmological scenarios related to physics beyond the Standard Model. It is then a major concern to constrain these approaches. Two-brane Universes involving [Formula: see text]-broken 5D bulks are among the cosmological models of interest. They also allow considering matter exchange between branes, a possible way to test these scenarios. Neutron disappearance (reappearance) toward (from) the hidden brane is currently tested with high-precision experiments to constrain the coupling constant [Formula: see text] between the visible and hidden neutron sectors. When dealing with the sub-GeV-scale quantum dynamics of fermions, any pair of braneworlds can be described by a noncommutative two-sheeted space–time [Formula: see text] from which [Formula: see text] emerges. Nevertheless, the calculation of the formal link between [Formula: see text] for a neutron and [Formula: see text]-broken 5D bulks remains an open problem until now although necessary to constrain these braneworld scenarios. Thanks to a phenomenological model, we derive [Formula: see text] — for a neutron — between the two braneworlds endowed with their own copy of the Standard Model in an [Formula: see text]-broken 5D bulk. Constraints on interbrane distance and brane energy scale (or brane thickness) are discussed. While brane energy scale below the GUT scale is excluded, energy scale up to the Planck limit allows neutron swapping detection in forthcoming experiments.

POSSIBLE CONSEQUENCES OF PARITY CONSERVATION

1992 ◽  
Vol 07 (28) ◽  
pp. 2567-2574 ◽  
Author(s):  
R. FOOT ◽  
H. LEW ◽  
R. R. VOLKAS
Keyword(s):  
Standard Model ◽  
Higgs Mass ◽  
Coupling Constants ◽  
Standard Model Higgs Boson ◽  
Solar Neutrino Problem ◽  
Decay Modes ◽  
Parity Conservation ◽  
The Standard Model ◽  
Two Parameters ◽  
Invisible Decay

It has been shown that parity may be an exact unbroken symmetry of nature. This requires a doubling of the number of physical particles, although only two parameters beyond those in the Standard Model are introduced. We show that the Lagrangian describing parity conserving models can be reformulated in terms of a basis in which each term of the Lagrangian is parity invariant, although gauge invariance is not manifest. We then examine some further experimental signatures of parity conservation. We point out that, in the simplest case, there is one parity-even and one parity-odd physical neutral Higgs mass eigenstate, whose Yukawa coupling constants are [Formula: see text]-that of the Standard Model Higgs boson. Furthermore, half of their widths are generated by almost invisible decay modes. Also, if neutrinos are massive then the ordinary and mirror neutrinos will, in the minimal case, be maximally mixed due to parity conservation. This means that vacuum oscillations can be large, thus providing a possible solution to the solar neutrino problem.

scholarly journals NON-SUSY AND SUSY ONE-STEP UNIFICATION

1998 ◽  
Vol 13 (26) ◽  
pp. 2153-2162 ◽  
Author(s):  
ABDEL PÉREZ-LORENZANA ◽  
ARNULFO ZEPEDA ◽  
WILLIAM A. PONCE
Keyword(s):  
Decay Rates ◽  
Coupling Constants ◽  
Gauge Models ◽  
The Standard Model ◽  
Low Energies ◽  
One Step ◽  
Standard Model Coupling ◽  
Model Independent ◽  
Supersymmetric Gauge ◽  
Experimental Values

We explore the possibility of achieving one-step unification of the standard model coupling constants within non-supersymmetric and supersymmetric gauge models, which at low energies have only the standard particle content. The constraints are the experimental values of αem, αs and sin 2θW at 102 GeV, and the lower bounds for FCNC and proton decay rates. The analysis is done in a model-independent way.

RARE B AND τ DECAYS AND SEARCHES FOR NEW PHYSICS

2007 ◽  
Vol 22 (30) ◽  
pp. 5433-5442
Author(s):  
R. J. BARLOW
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Excellent Agreement ◽  
Rare Decays ◽  
B Mesons ◽  
New Physics ◽  
B Decays ◽  
The Standard Model ◽  
Model Predictions ◽  
Vector Particles

New results on rare decays of B mesons and τ leptons are summarised. Measurement are generally in excellent agreement with the Standard Model predictions, the only exceptions being the polarisation of vector particles in B decays and the non-appearance of CP violation in B ± → K ±π0.

scholarly journals MINIMIZATION OF THE SCALAR HIGGS POTENTIAL IN THE FINITE SUPERSYMMETRIC GRAND UNIFIED THEORY

1996 ◽  
Vol 11 (05) ◽  
pp. 989-1006 ◽  
Author(s):  
I.N. KONDRASHUK
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Supersymmetric Standard Model ◽  
Electroweak Symmetry Breaking ◽  
Higgs Potential ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Electroweak Symmetry ◽  
Mathematical Solution ◽  
Simple Generalization

An exact mathematical solution of the minimization conditions of the scalar Higgs potential of the finite supersymmetric grand unified theory is proposed and extremal field configurations are found. Types of extrema are investigated and masses of the new Higgs particles arising after electroweak symmetry breaking are derived analytically. The conditions for the existence of a physically acceptable minimum are given. As it appears, this minimum is a simple generalization of the analogous solution in the minimal supersymmetric standard model. Phenomenological consequences are discussed briefly.

General structure of democratic mass matrix of lepton sector in E6 model

2018 ◽  
Vol 96 (7) ◽  
pp. 834-836
Author(s):  
A.K. Çiftçi ◽  
R. Çiftçi
Keyword(s):  
Mass Matrix ◽  
General Structure ◽  
Mass Difference ◽  
Theory Model ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Matrix Elements ◽  
Lepton Sector ◽  
Natural Approach ◽  
The Standard Model

An extension of the Standard Model (SM) fermion sector, which is inspired by the E6 grand unified theory model, may be a good candidate to explain a number of unanswered questions in SM. Existence of the E6 leptons may explain great mass difference of charged and neutral leptons. Also, democracy on mass matrix elements is a natural approach in SM. In this study, we have given general structure of democratic mass matrix of lepton sector in E6 model.

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