The idea that fermions acquire their masses via a universal seesaw mechanism can provide a plausible explanation for the mass hierarchy m e , u ,d -10 ~4Mw> A minimal SU(3)c®SU(2)£®SU(2)/? ®U(1 )B-L grand-uniflable realization is presented. Whereas the fermionic representation is enlarged to include SU(2)L ®SU(2)/? singlets, the Higgs system contains none of the conventional scalars of leftright-symmetric models. An alternative way to account for the superlightness of neutrinos emerges.PACS numbers: 12.15.Ff, 12.10.Dm A remarkable, yet still somewhat mysterious, feature of the Glashow-Weinberg-Salam electroweak scheme 1 is that spontaneous symmetry breaking and fermion masses are both triggered by one and the same Higgs scalar. On the one hand, it is useful to have some guidance as to how to choose the otherwise arbitrary Higgs system. On the other hand, it seems as if naturalness is lost in the following sense. If the electron and the W bosons acquire mass via a common vacuum expectation value, why is it thatFurther, this mass hierarchy is numerically not so different from m Ve <\0~5m ejbut somehow it has not received due attention. The latter hierarchy is not confronted in the minimal electroweak model. Whereas the difficulty associated with m e <^Mw persists when SU(2) L ®U(l) r is enlarged 2 to SU(2) L <8>SU(2)R<8>U(I)B-L, the m Ve <^m e problem can be addressed by invoking the so-called seesaw mechanism. 3 The higher the mass scale of the now mandatory VR (which is not the case in the standard electroweak model), the lighter is v L . The price, however, is a richer Higgs system which necessarily includes 4 0(2,2) o + 0(3,0-2 + 0(1,3) -2 .(What physics gives rise to m e /M w <3C 1 ? Is there an alternative way to account for m v Jm e <^ 1? Are these two hierarchies correlated?In an attempt to deal with the above questions, we have adopted an unorthodox approach. Rather than sticking to a fixed fermionic set while complicating the Higgs system, we hereby enlarge the fermionic representation but simplify the Higgs system to its limits. In particular, none of the conventional scalars specified by Eq.(3) are present! Yet, the electron does acquire mass, via a universal seesaw mechanism, and at the same time the superlightness of the neutrinos follows without any fur-ther input. The scheme lends itself to SU(5) L <8>SU(5)/? grand unification. 5
As a model, the Pais-Uhlenbeck fourth order oscillator with equation of motion
Within the framework of geodetic brane gravity, the Universe is described as a 4-dimensional extended object evolving geodetically in a higher dimensional flat background. In this paper, by introducing a new pair of canonical fields {λ, P λ }, we derive the quadratic Hamiltonian for such a brane Universe; the inclusion of matter then resembles minimal coupling. Second class constraints enter the game, invoking the Dirac bracket formalism. The algebra of the first class constraints is calculated, and the BRST generator of the brane Universe turns out to be rank-1. At the quantum level, the road is open for canonical and/or functional integral quantization. The main advantages of geodetic brane gravity are: (i) It introduces an intrinsic, geometrically originated, 'dark matter' component, (ii) It offers, owing to the Lorentzian bulk time coordinate, a novel solution to the 'problem of time', and (iii) It enables calculation of meaningful probabilities within quantum cosmology without any auxiliary scalar field. Intriguingly, the general relativity limit is associated with λ being a vanishing (degenerate) eigenvalue.
Quark-lepton correspondence and the corresponding interpretation of B -L as the fourth color are combined in an SU(2), X U(1), X U1(i) electroweak model. The right-handed neutrino interactions are automatically suppressed and the standard model is recovered up to a desirable first-order fine structure. A fundamental distinction is established between the real Weinberg angle and its effective (measured) values. For neutrino interactions, our predictions are in general of the Weinberg-Salam (WS) type, only with the effective replacement sin20, -sin2%:; such that (a) sin20$ (purely leptonic processes) > sin20EF (vq scattering), and (b) for sin2@, = 1/4 one can still have a lower value for the weighted average of sin2@$. Our expressions for the asymmetry parameter in electron-induced reactions agree with those of the WS model up to a second-order term. The additional neutral gauge boson is expected to be only 1 order of magnitude heavier than W*. We argue that the present neutral-current experimental data are not capable of distinguishing between the standard and the present models. Finally we discuss the possibility of embedding our model in a unified gauge theory, showing that only spinorial SO(4k + 2) theories are available for this purpose.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.