Lepton models

N. C. Petroni, Z. Marie, Dj. Zivanovic, and J. P. Vigier, Stable states of a relativistic bilocal stochastic oscillator A new quark-lepton model, J. Phys. A (Special Issue Mathematical and General) 14(2), 501-508 (1981). 

Following a leptonic model, gamma rays may arise from inverse Compton (IC) processes when the relativistic electrons of the jet interact with external photons from the massive companion star. If the jets are hadronic, the gamma rays may come from the decay of neutral pions in the interaction between protons from the jet and ions from the wind of the companion star. 

Table I presents the estimate of the electron EDM predicted by different particle physics models [8, 9]. As can be seen from this table, the value of the electron EDM in the SM is 10-12 orders of magnitude smaller than in the other models. This is due to the fact that the first nonvanishing contribution to this quantity arises from three-loop diagrams [30]. There are strong cancellations between diagrams at the one-loop as well as two-loop levels. It is indeed significant that the electron EDM is sensitive to a variety of extensions of the SM including supersymmetry (SUSY), multi-Higgs, left-right symmetry, lepton...

Second, this decay allows to study the nature of p,ui and (ft— meson mixing. Note,that in references (Nasriddinov, 1994 Nasriddinov, 2001) the problems of 7r° — rj - and io — (ft mixings have been studied on the basis of this model as well and obtained reasonable results for the r-lepton decay probabilities. In this calculation, we used ui — 0-mixing... 

As is mentioned in the introduction, the observation of a non-zero EDM would point out the presence of so called new physics (see [30, 1] and references) beyond the Standard Model [2, 3, 4, 5, 31] or CP violation in the QCD sector of SM, SU 2>)c- The discovery of a lepton EDM (electron EDM in our case) would have an advantage as compared to the cases of neutron or proton EDMs because the latter are not considered as elementary particles within the SM and its extensions. 

The present configuration could become a model for charged leptons. With these conditions imposed, the integrated charge qo has been given by [20]... 

The atom was once thought to be the smallest unit of matter, but was then found to be composed of electrons, protons, and neutrons. The question arises are electrons, protons, and neutrons made of still smaller particles In the same way that Rutherford was able to deduce the atomic nucleus by bombarding atoms with alpha particles (Chapter 3), evidence for the existence of many other subatomic particles has been obtained by bombarding the atom with highly energetic radiation.This research over the past centmy has evolved into what is known as the "standard model of fundamental particles, which places all constituents of matter within one of two categories quarks and leptons. 

Woosley et al. (1984), and the compressible liquid drop model EOS of Lamb et al. (1978) up to nuclear densities. At higher densities we added to the lepton pressure a cold pressure as given by Baron et al. in the... 

Particle groups, like fermions, can also be divided into the leptons (such as the electron) and the hadrons (such as the neutron and proton). The hadrons can interact via the nuclear or strong interaction while the leptons do not. (Both particle types can, however, interact via other forces, such as the electromagnetic force.) Figure 1.4 contains artistic conceptions of the standard model, a theory that describes these fundamental particles and their interactions. Examples of bosons, leptons, hadrons, their charges, and masses are given in Table 1.6. 

Ph. Gueret, and J. P. Vigier, Unification des quarks et des leptons dans la representation de la base de SO(6,l) [Sakata-Yukawa model unifying quarks and leptons in the total dynamic group SO(6,l)], C. R. Acad. Sci. Paris 270(10), 653-656 (1970). 

Here G"v and F v are elements of the field strength tensors for the two SU(2) principal bundles. So far the theory is entirely parallel to the basic standard model of electroweak intereactions. In further work the Dirac and Yukawa Lagrangians that couple the Higgs field to the leptons and quarks will be included. It will then be pointed out how this will modify the B field. The < )4 field may be written according to a small displacement in the vacuum energy ... 

This theory has the advantage over the 50(5) minimal model that the various right- and left-handed quarks and leptons are treated equivalently in the 16 representation. This leaves the B — L boson is a 0(1) transformation that acts on the quarks, but not the leptons. This term is then a a that acts on each of the (u, d) doublets. This boson is referred to in the B - L boson in the Pati-Salam model. 

It is apparent that the numbers and masses of the flavor and quark-lepton transforming gauge bosons are larger than those of the SU(5) minimal model. This means that the value of a is lower, and assuming that the duration of the inflationary period is fixed, the scale for the expansion of the universe is reduced. This means that there is the enhanced prospect for deviations from flatness. So one may presume that the universe started as a small 3-sphere with a large curvature, where the inflationary period flattened out the universe, but maybe not completely. This leaves open the prospect that if before inflation that if the universe were open or closed, k = 1, that the universe today still contains this structure on a sufficiently large scale. The closer to flatness the universe is, the tighter are the constraints on the masses of particles in the early universe. 

Even if allowed by the CPT theorem, the non-conservation of CP symmetry was hard to accept - not least because it was not consistent with the Standard Model. In 1972, Kobayashi and Maskawa predicted that CP violation would be consistent with the Standard Model provided that three generations of quarks exist (and only two were known at the time). The subsequent discoveries of the r lepton by Pearls (1975) and of the top and bottom quarks at the Fermilab confirmed the existence of a third family, this resulted in the incorporation of the CP violation into the Standard Model. 

Heavy neutrino The WIMP par excellence is a heavy neutrino. The example we consider is a thermal Dirac neutrino v of the fourth generation with Standard Model interactions and no lepton asymmetry. Figure 3 summarizes... 

Abstract. Muonium is a hydrogen-like system which in many respects may be viewed as an ideal atom. Due to the close confinement of the bound state of the two pointlike leptons it can serve as a test object for Quantum Electrodynamics. The nature of the muon as a heavy copy of the electron can be verified. Furthermore, searches for additional, yet unknown interactions between leptons can be carried out. Recently completed experimental projects cover the ground state hyperfine structure, the ls-2s energy interval, a search for spontaneous conversion of muonium into antimuonium and a test of CPT and Lorentz invariance. Precision experiments allow the extraction of accurate values for the electromagnetic fine structure constant, the muon magnetic moment and the muon mass. Most stringent limits on speculative models beyond the standard theory have been set. 

Beyond atomic spectroscopy muonium renders the possibility to search directly and sensitively for yet unknown interactions between the two charged leptons from two different generations. Among the mysteries observed for leptons are the apparently conserved lepton numbers. As a matter of fact, several distinctively different lepton number conservation schemes appear to hold, some of which are additive and some are multiplicative, parity-like. Some of them distinguish between lepton families and others don t [46,47,48,49,50]. No local gauge invariance has been revealed yet which would be associated with any of these empirically established laws. Since there is common believe [51] that any discrete conserved quantity is connected to a local gauge invariance, a breakdown of lepton number conservation is widely expected, particularly in the framework of many speculative models. 

A potential M-M-conversion would violate additive lepton family number conservation and is discussed in many of the speculative theoretical approaches (see Fig. 10). It would be a full analogy in the sector of leptons to K°-K oscillations, which are well known and established in the quark sector of the standard model. 

This new result, which exceeds bounds from previous experiments [58,64] by a factor of 2500 and the one from an early stage of the experiment [59] by 35, has some impact on speculative models. A certain model is ruled out with more than 4 generations of particles where masses could be generated radiatively with heavy lepton seeding [66]. A new lower limit of... 

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