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

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.

2015 ◽  
Vol 30 (30) ◽  
pp. 1530060
Author(s):  
Hong-Mo Chan ◽  
Sheung Tsun Tsou

Apart from the qualitative features described in Paper I (Ref. 1), the renormalization group equation derived for the rotation of the fermion mass matrices are amenable to quantitative study. The equation depends on a coupling and a fudge factor and, on integration, on 3 integration constants. Its application to data analysis, however, requires the input from experiment of the heaviest generation masses [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] all of which are known, except for [Formula: see text]. Together then with the theta-angle in the QCD action, there are in all 7 real unknown parameters. Determining these 7 parameters by fitting to the experimental values of the masses [Formula: see text], [Formula: see text], [Formula: see text], the CKM elements [Formula: see text], [Formula: see text], and the neutrino oscillation angle [Formula: see text], one can then calculate and compare with experiment the following 12 other quantities [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and the results all agree reasonably well with data, often to within the stringent experimental error now achieved. Counting the predictions not yet measured by experiment, this means that 17 independent parameters of the standard model are now replaced by 7 in the FSM.


1996 ◽  
Vol 11 (12) ◽  
pp. 965-971
Author(s):  
D. GÓMEZ DUMM

We study the evolution of fermion mass matrices considering the hypothesis of approximate flavor symmetries (AFS) in the standard model and a two-Higgs-doublet model. We find that the hierarchical structure is not significantly altered by the running, hence the assumption of AFS is entirely compatible with a grand unification scenario.


2003 ◽  
Vol 18 (27) ◽  
pp. 1877-1885 ◽  
Author(s):  
J. Besprosvany

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.


2014 ◽  
Vol 92 (12) ◽  
pp. 1501-1527 ◽  
Author(s):  
Carlos Castro

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.


Author(s):  
Ivan A. Shershan ◽  
Tatiana V. Shishkina

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.


2016 ◽  
Vol 94 (11) ◽  
Author(s):  
Samandeep Sharma ◽  
Gulsheen Ahuja ◽  
Manmohan Gupta

Author(s):  
Yoshiharu Kawamura

Abstract We propose a bottom-up approach in which a structure of high-energy physics is explored by accumulating existence proofs and/or no-go theorems in the standard model or its extension. As an illustration, we study fermion mass hierarchies based on an extension of the standard model with vector-like fermions. It is shown that the magnitude of elements of Yukawa coupling matrices can become $O(1)$ and a Yukawa coupling unification can be realized in a theory beyond the extended model, if vector-like fermions mix with three families. In this case, small Yukawa couplings in the standard model can be highly sensitive to a small variation of matrix elements, and it seems that the mass hierarchy occurs as a result of fine tuning.


1997 ◽  
Vol 12 (04) ◽  
pp. 723-742 ◽  
Author(s):  
P. Bamert

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.


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