Showing papers on "Gauge boson published in 1979"

Horizontal symmetry and masses of neutrinos

Abstract: Assuming a horizontal symmetry SU_F(n), we demonstrate a possibility that the left-handed neutrinos receive masses of order 1eV, which is consistent with recent experiments on neutrino oscillations. The smallness of the neutrino masses is an indication of a large breaking of the horizontal symmetry.

Phase diagrams of lattice gauge theories with Higgs fields

Abstract: We study the phase diagram of lattice gauge theories coupled to fixed-length scalar (Higgs) fields. We consider several gauge groups: ${Z}_{2}$, U(1), and $\mathrm{SU}(N)$. We find that when the Higgs fields transform like the fundamental representation of the gauge group the Higgs and confining phases are smoothly connected, i.e., they are not separated by a phase boundary. When the Higgs fields transform like some representation other than the fundamental, a phase boundary may exist. This is the case for $\mathrm{SU}(N)$ with all the Higgs fields in the adjoint representation and for U(1) with all the Higgs fields in the charge-$N(Ng1)$ representation. We present an argument due to Wegner that indicates the stability of the pure gauge transition. Another phase, free charge or Coulomb, is generally present. In this regime, the spectrum of the theory contains massless gauge bosons (for continuous groups) and finite-energy states that represent free charges.

Broken-symmetric theory of gravity

Abstract: A theory of gravity incorporating the concept of spontaneous symmetry breaking is proposed. It is suggested that the same symmetry-breaking mechanism is responsible for breaking a unified gauge theory into strong, weak, and electromagnetic interactions.

Deformations of gauge groups. Gravitation

Abstract: This is a review, and an attempt at completion, of the ’’Gupta program,’’ the ultimate goal of which is either to show that Einstein’s theory of gravitation is the only self‐consistent field theory of interacting, massless, spin‐2 particles in flat space or to discover interesting alternatives. It is useful to notice that the gauge group of general relativity is a deformation (in a mathematically precise sense) of the gauge group associated with the massless, spin‐2 free field. The uniqueness of Einstein’s theory depends on the stability of its gauge group with respect to a class of differentiable deformations. A generalized Gupta program for massless fields of arbitrary spins is proposed.

Hidden gauge symmetry

Abstract: The past 15 years has seen the gradual emergence of the idea that the fundamental physical interactions are determined by gauge symmetry or, more precisely, by hidden (spontaneously broken) gauge symmetry. The importance of gauge symmetry is that it reduces considerably the possible forms of interaction, gives the interactions a geometrical meaning, and introduces a certain degree of unification to the different known interactions (gravitational, weak, etc.). A description of the principles of hidden gauge symmetry and of its application ot the fundamental interactions is presented. The emphasis is on the structure, gauge symmetry and hidden symmetry are first treated as independent phenomena before being combined into a single (hidden gauge symmetry) theory. The main application of the theory is to the weak and electromagnetic interactions of the elementary particles, and although models are used for comparison with experiment and for illustration, emphasis is placed on those features of the application which are model-independent.

Flavor Unification, $\tau$ Decay and $b$ Decay Within the Six Quark Six Lepton {Weinberg-Salam} Model

Abstract: The leptons ..nu../sub e/, e, ..nu../sub ..mu../, ..mu.., ..nu../sub tau/, tau, and analogously the quarks u, d, c, s, t, b, are unified within the Weinberg-Salam SU/sub 2/ x U/sub 1/ gauge model without enlarging the gauge group. The result is a theory in which the familiar leptons, quarks, and gauge bosons, plus some extra Higgs bosons necessary for unification, all carry a new multiplicatively conserved quantum number ..pi.. = +- 1. The most striking results of this unification are (1) ..pi.. conservation forbids ..mu.. ..-->.. e..gamma.. but allows the Higgs-boson-mediated decays tau ..-->.. l..gamma.. (l = e or ..mu..) and tau ..-->.. ..mu..ee or e..mu mu.., at a calculable rate with a calculable lower limit; (2) for quarks, two of the three Cabibbo angles must be zero, so that the b quark (assumed lighter than t) decays only via Higgs-boson exchange, always semileptonically and always with lepton-number violation, e.g., b ..-->.. de/sup +/..mu../sup -/. This singular prediction will confirm or exclude the model as soon as b-flavored mesons are discovered. These and other phenomenological consequences of this unification are explained, and rates are estimated.

W/sup + -/Z/sup 0/ and W/sup + -/. gamma. pair production in. nu. e, pp, and p-barp collisions

Abstract: We augment a previous discussion of the production of pairs of gauge bosons with a study of the reactions pp and p-barp --> WZ/sup 0/X or WgammaX As before, these depend upon trilinear boson couplings and the high-energy behavior is controlled by gauge cancellations In particular, the (hard) photon production is sensitive to the magnetic-moment parameter kappa for the W We also discuss the related neutrino reactions, nue --> WZ/sup 0/ or Wgamma, which may be of interest in very-high-energy cosmic-ray physics

Interference, gravity and gauge fields

Abstract: The phase shift due to gravitational field and all gauge fields in the interference of two coherent beams is obtained. In the case of gravitation, it is shown, for a particle with arbitrary spin, that there exists a phase shift due to the coupling of spin to space-time curvature. This and the corresponding phase shift for gauge fields are analogous to the Aharonov-Bohm effect. The classical limit for particles moving in gravitational and gauge fields is obtained from the phase shift. For gravitation, in the absence of torsion, this is the Mathisson-Papapetrou equation, which is thereby shown to be the classical limit of the Dirac and Bargmann-Wigner wave equations, generalized to curved space-time. In the presence of torsion, a modification of this equation, given by Hehl, is obtained. It is pointed out that gravity is not a pure gauge field and that it must be placed in the more general category of an «interference field» which contains both gravity and gauge fields as special cases. The field equations for gauge fields and gravity are obtained from the heuristic assumption that a particle acts on a field in a manner which depends on how it responds to the field via the phase shift. For gauge fields, they contain the Yang-Mills equations as a special case. For gravity, a modification of Einstein’s field equations is obtained, which corresponds to the Lagrangian (1/16πK) ·, · (2Λ +R) + (1/32πf)RμνϱσRμνσϱ, where the Riemann tensor contains torsion andK, f, Λ are constants (Λ may be zero). The relevance of the phase shift, due to rotation, to the quantization of vortices in superfluid helium is pointed out. This suggests that the curl of the superfluid velocity may obey a system of equations analogous to Maxwell’s equations and the analogue of the magnetic monopole for superfluid helium is also introduced.