Showing papers on "Gauge boson published in 1992"
Book•
31 Jul 1992TL;DR: In this paper, the S = 1 interaction was introduced and the Kaon mixing and CP violation was investigated in the context of the large N expansion of the standard QCD model.
Abstract: Preface Inputs to the standard model Interactions of the standard model Symmetries and anomalies Introduction to effective Lagrangians Leptons Very low energy QCD - Pions and photons Introducing kaons and etas Kaons and the S=1 interaction Kaon mixing and CP violation The large N expansion Phenomenological models Baryon properties Hadron spectroscopy Weak interactions of heavy quarks The Higgs boson The electroweak gauge bosons Appendices References Index.
1,058 citations
TL;DR: A chiral model based on a gauge group SU(3), which contains dilepton gauge bosons and new quarks with exotic charges-4/3 and +5/3, although coincident at low energy with the standard model, in the extended theory the third quark family is treated differently from the first two.
Abstract: A chiral model based on a gauge group SU(3){sub {ital C}}{times}SU(3){sub {ital L}}{times}U(1){sub {ital X}} contains dilepton gauge bosons and new quarks with exotic charges-4/3 and +5/3. Although coincident at low energy with the standard model, in the extended theory the third quark family is treated differently from the first two, and anomaly cancellation requires that the number of families be equal to the number of quark colors.
578 citations
TL;DR: In this article, the lepton number is violated explicitly by charged scalar and gauge bosons, including a vector field with double electric charge, in a model based on a SU(3)-ensuremath{\bigotimes}U(1) symmetry.
Abstract: We consider a gauge model based on a SU(3)\ensuremath{\bigotimes}U(1) symmetry in which the lepton number is violated explicitly by charged scalar and gauge bosons, including a vector field with double electric charge.
565 citations
TL;DR: In this paper, the authors consider one-loop effects induced by the dimension-six operators (D ω Φ) √ gT i W i ων (D ν Φ ) and gG − gYB √ G − g − Φ √ YB ωγ ) and show that such effects at most logarithmically divergent, as required by decoupling, imply modest constraints on the size of new physics signals.
151 citations
TL;DR: The effective equation of motion for the Higgs field, and the approximate shape of the moving bubble wall are computed, which shows that the bubble walls propagate with a mildly relativistic speed.
Abstract: We discuss the nucleation and growth of bubbles of the broken-symmetry phase of matter at the electroweak phase transition. We show that the bubble walls propagate with a mildly relativistic speed. The Lorentz $\ensuremath{\gamma}$ factor depends on the ratio of the Higgs to gauge-boson mass---for parameters allowing for baryogenesis at the transition (i.e., a fairly light Higgs mass) we find $\ensuremath{\gamma}v\ensuremath{\sim}1$. We show that the bubble wall is mainly slowed by interactions with low-momentum gauge-boson pairs, and compute the damping rate due to these interactions. The width of the bubble wall is significantly larger than the typical wave-length of particles which are reflected from it, which allows us to use a WKB approximation for the particle scattering. The width is also larger than the mean free path for these particles, which means that the gauge boson fluid remains close to local thermal equilibrium. This situation results in mildly relativistic motion of the bubble wall. As a result, the baryon-number excess produced on the bubble wall is not much diluted by subsequent diffusion. We compute the effective equation of motion for the Higgs field, and the approximate shape of the moving bubble wall.
117 citations
TL;DR: The field equations for the gauge potentials, for pointlike sources, and for scalar and spinor matter fields reproduce the Einstein equations, the geodesics equations, and the Klein-Gordon and the Dirac equations in curved space-time, respectively.
Abstract: We discuss gravity as a gauge theory of the Poincare group in three and four dimensions, i.e., in a metric-independent fashion. The fundamental fields of the theory are the gauge potentials, the matter fields, and the so-called Poincare coordinates {ital q}{sup {ital a}}({ital x}): a set of fields that are defined on the space-time manifold, but that transform as Poincare vectors under gauge transformations. The presence of such coordinates is necessary in order to construct a gauge theory of the Poincare group. We discuss the procedure needed to connect this theory with the Einsteinian formulation of gravity, and we show that the field equations for the gauge potentials, for pointlike sources, and for scalar and spinor matter fields reproduce the Einstein equations, the geodesics equations, and the Klein-Gordon and the Dirac equations in curved space-time, respectively. In 2+1 dimensions and in the presence of pointlike sources this gauge-theoretical approach can be further developed: the gauge potentials can be written almost everywhere as pure gauge, and a solution of the field equations provides, at the same time, the space-time metric and the set of coordinates that globally flatten the metric.
94 citations
TL;DR: Numerical evidence is presented that the real-time Hamiltonian dynamics of SU(2) gauge theory on a spatial lattice exhibits deterministic chaos in the semiclassical limit.
Abstract: We present numerical evidence that the real-time Hamiltonian dynamics of SU(2) gauge theory on a spatial lattice exhibits deterministic chaos in the semiclassical limit. We determine the largest Lyapunov exponent of the gauge field as a function of energy density, and derive a nonperturbative expression for the thermalization time.
79 citations
TL;DR: In this paper, the partial widths of the fermionic Higgs-boson decays are calculated in the one-loop approximation of the minimal standard model of electroweak interactions.
74 citations
TL;DR: In this paper, the running coupling constant for a range of R-values and hence estimate the scale Λ MS was derived from an accurate determination of the interquark potential.
68 citations
TL;DR: Calculations with anomalous trilinear gauge boson vertices have been criticized as overestimates due to a failure to incorporate gauge invariance, but it is shown that they are gauge invariant, although this symmetry is realized nonlinearly.
Abstract: Calculations with anomalous trilinear gauge boson vertices have been criticized as overestimates due to a failure to incorporate gauge invariance. We show here that the criticized calculations [ital are] gauge invariant, although this symmetry is realized nonlinearly. We instead trace the overestimates to an incorrect treatment of cutoffs in loop diagrams.
65 citations
TL;DR: In this paper, the gauge dependence of some basic one-loop electroweak corrections of the Standard Model (SM) is succinctly described in terms of three functions of the vector boson masses, the gauge parameters and the invariant momentum transfer.
TL;DR: In this article, the induced action Γ[h, b] for chiral W3 gravity in the c→±∞ limit was obtained by imposing constraints on the currents of the Wess-Zumino-Witten model.
Abstract: We obtain the induced action Γ[h, b] for chiralW3 gravity in thec→±∞ limit from the induced action of a gaugedSl(3,R) Wess-Zumino-Witten model by imposing constraints on the currents of the latter. In the process we find a closed gauge algebra for the gauge sector ofW3 gravity in which the currentsT andW become auxiliary fields. An explicit realization ofT andW in terms of the gauge fields is given. In terms of new fieldsr ands, which are a generalization of Polyakov'sf variable for ordinary gravity, the complete induced action Γ[h, b; c→±∞] becomes local.
[...]
TL;DR: The condition that must be satisfied by the pattern of symmetry breakdown for finite-energy configurations to exist in which the conserved magnetic flux is spread out instead of confined to a localized vortex is formulated and vortices are always unstable at sufficiently weak gauge coupling.
Abstract: I analyze the interplay of gauge and global symmetries in the theory of topological defects In a two-dimensional model in which both gauge symmetries and {\it exact} global symmetries are spontaneously broken, stable vortices may fail to exist even though magnetic flux is topologically conserved Following Vachaspati and Achucarro, I formulate the condition that must be satisfied by the pattern of symmetry breakdown for finite-energy configurations to exist in which the conserved magnetic flux is spread out instead of confined to a localized vortex If this condition is met, vortices are always unstable at sufficiently weak gauge coupling I also describe the properties of defects in models with an ``accidental'' symmetry that is partially broken by gauge boson exchange In some cases, the spontaneously broken accidental symmetry is not restored inside the core of the defect Then the structure of the defect can be analyzed using an effective field theory; the details of the physics responsible for the spontaneous symmetry breakdown need not be considered Examples include ``semilocal'' domain walls and vortices that are classically unstable, but are stabilized by loop corrections, and ``semilocal'' magnetic monopoles that have an unusual core structure Finally, I examine the general theory of the ``electroweak strings'' that were recently discussed by Vachaspati These arise only in models with gauge boson ``mixing,'' and can always end on magnetic monopoles Cosmological implications are briefly discussed
01 Jan 1992
TL;DR: In this paper, the mass of the CP=+1 lightest Higgs boson is bounded by ∼110 GeV for mt<150 GeV and a scale of supersymmetry breaking ∼1 TeV.
Abstract: In the minimal supersymmetric standard model (MSSM), when radiative corrections are included, the mass of the CP=+1 lightest Higgs boson is bounded by ∼110 GeV for mt<150 GeV and a scale of supersymmetry breaking ∼1 TeV. In non‐minimal supersymmetric standard models (NMSSM) upper bounds on the mass of the corresponding scalar Higgs boson arise if the theory is required to remain perturbative up to scales ≫G−1/2F. We have computed those bounds for two illustrative NMSSM: i) A model with an arbitrary number of gauge singlets; ii) A model with three SU(2)L triplets with Y=0, ±1. We have integrated numerically the corresponding renormalization group equations (RGE), including the top and bottom quark Yukawa couplings, and added one‐loop radiative corrections. For mt≳91 GeV the absolute bounds are ∼140 GeV for both models.
TL;DR: In this article, the effects of additional neutral gauge bosons at future colliders were analyzed and a simple formalism was developed to describe these effects and a careful study of radiative corrections, in particular initial state radiation, was made.
Abstract: We analyze possible indirect signals of additional neutral gauge bosons at futuree
+
e
− colliders, concentrating onSU(2)
L
×U(1)
y
×U(1)
y
, andSU(2)
L
×SU(2)
R
×U(1) effective theories We develop a simple formalism to describe these effects and make a careful study of radiative corrections, in particular initial state radiation, which will be shown to have important implications To make realistic estimates of the sensitivity to the new gauge boson effects, we use a model detector fore
+
e
− annihilation at a center of mass energy of 500 GeV Using a number of selected physical observables we then show that masses considerably higher than the total energy (up to a factor of 6) can be probed and that distinction between various theoretical models is possible
TL;DR: In this article, the authors analyse quadratic divergences using di-mensional regularization in gauge theories in general and the standard model in particular and give a prediction (under dubious assumptions) that retell5 GeV and mn ~ 180 GeV.
Abstract: Quadratic divergences are analysed using di- mensional regularisation in gauge theories in general and the standard model in particular. We give a prediction (under dubious assumptions) that retell5 GeV and mn ~ 180 GeV.
CERN1
TL;DR: In this article, a renormalizable model with a scale of new physics in the multi-TeV range is constructed and the top mass predictions as well as the phenomenology is discussed; it turns out that the effective lagrangian contains more than the usual Higgs sector, which makes the scenario clearly distinguishable; in particular it is shown that for the strong coupling not all of the effects decouple as the heavy mass goes to infinity and there can be negative contributions to the ϱ-parameter, thereby somewhat relaxing the stringent experimental upper bounds on the topmass.
TL;DR: The numerical importance of the obtained results is shown for QED and QCD corrections to r, b and t-quark production in this article, and they are immediately applicable to theories with several neutral gauge bosons.
Abstract: Analytic results for final state corrections to the differential and total cross-section for e+e−→massive fermions are presented. In the phase space integration a cut 011 the photon energy was included. The numerical importance of the obtained results is shown for QED and QCD corrections to r, b and t-quark production. Final state corrections are changed considerably by applying a cut on the photon energy. All results are immediately applicable to theories with several neutral gauge bosons.
TL;DR: In this article, it was shown that the ϱ meson dominance of the pion electromagnetic form factor survives the one-loop corrections at any momentum, if and only if the parameter choice a=2 is not renormalized.
TL;DR: In this paper, a representation of the field operators in a Hilbert space ℋ with the following features was constructed for the linearized Higgs model: the field operator has a positive definite metric but is nonseparable.
Abstract: We construct for the linearized Higgs model a representation of the field operators in a Hilbert space ℋ with the following features: ℋ has a positive definite metric but is nonseparable. The vacuum is gauge invariant. The gauge variant operators exist only in their exponentiated form as unitaries. There is a subspace of ℋ where ${\mathcal A}_\mu^{,\,\mu}$ is represented by 0.
TL;DR: In this article, the authors presented a 95% confidence level (C.L.) limit on the Z'→μ + m -production cross section, assuming standard-model coupling strengths.
Abstract: We have searched for the production of a neutral gauge boson (Z') with mass above 100 GeV/c 2 in pp collisions with the Collider Detector at Fermilab. We present a 95% confidence level (C.L.) limit on the Z'→μ + m - production cross section. We combine the Z' limit with that from our previous dielectron search; the combined result sets a limit of MZ'>412 GeV/c 2 (95% C.L.), assuming standard-model coupling strengths
TL;DR: In this article, a new construction of the Standard Model based on the graded Lie algebra SU(2|1) is analyzed in some depth and the essential ingredient is an algebraic superconnection which incorporates both the gauge fields and the Higgs fields and whose curvature automatically leads to a spontaneously broken realization of the theory.
Abstract: A recently proposed, new construction of the Standard Model based on the graded Lie algebra SU(2|1) is analyzed in some depth. The essential ingredient is an algebraic superconnection which incorporates both the gauge fields and the Higgs fields and whose curvature automatically leads to a spontaneously broken realization of the theory. The mechanism of hiding the original algebraic structure is unorthodox and is due to the specific, "noncommutative" realization of SU(2|1). The model is characterized by a constant background supercurvature which is invariant under arbitrary, constant SU(2|1) gauge transformations. This background field whose effect is analogous to the action of a constant magnetic field on a spherical atom, is traced back to the differential in the space of (super)matrices by means of which the supercurvature is constructed. The same background field is responsible for the fact that the ground state has no more than the U(1)e.m. symmetry of electromagnetism, the SU(2)L × U(1) symmetry of the Standard Model being recovered only after "backshifting" the Higgs fields. Thus, the Higgs mechanism receives a new and geometrical interpretation.
TL;DR: In this paper, it was shown that SU (N) theories with fermions have metastable states related to the ZN symmetry of the theory and that these states, generically, have unaacceptable thermodynamic behavior.
TL;DR: In this article, the authors examined recent claims that experiments on neutron-decay are at variance with the standard V-A helicity structure of the standard model and concluded that there is a right-handed weak gauge boson with mass between 207 and 369 GeV c2 at 95% CL.
Abstract: The authors examine recent claims that experiments on neutron-decay are at variance with the standard V-A helicity structure of the standard model. The analysis presented here combines the neutron data with other recent experimental results and theoretical elaborations in the field of nuclear beta decay. If interpreted in the framework of left-right symmetric models, the data favour the existence of a right-handed weak gauge boson with mass between 207 and 369 GeV c2 at 95% CL. The fit using the standard V-A helicity structure has a chi 2 of 8.52 for four degrees of freedom and excludes the V-A solution at 2.53 standard deviations. This exclusion is due mainly to the new neutron asymmetry data and is in disagreement with the conclusions drawn from muon decay and from the KL-KS mass difference in the framework of manifest left-right symmetric models.
TL;DR: In this paper, the effects of a strongly interacting symmetry breaking sector of the standard model in γγ→WL+WL− and λγ→ZLZL reactions at TeV energies were analyzed by using chiral lagrangians and chiral perturbation theory.
TL;DR: In this paper, an improved limit of M x 230 GeV was obtained for the mass of a dileptonic gauge boson predicted in certain unified theories, based on the analysis of the angular distribution of electrons in polarized muon decay.
TL;DR: In this article, the authors derived mathematical identities proving that some systems of interacting, non-relativistic fermions of spin or isospin S = 1 2, 3 3, 5 2,… confined to a plane (e.g. a heterojuncture) can be described in terms of a complex boson of spin S coupled to statistical U(1) and SU(2) gauge fields, and applications of their formalism to an analysis of excitations with braid statistics in incompressible quantum fluids and of holons and spinons in
01 Jan 1992
TL;DR: In this paper, a new principle relating to the fermion mass terms in the Lagrangian has been adopted, and the mass term is factorised and the frame field is introduced into the covariant derivative, giving rise to mass terms for the bosons mediating the interactions.
Abstract: This paper is divided into three sections In the first section we consider the principles of spin gauge theories which includes the differences between them and standard gauge theories Some of these principles may be familiar to those who have seen the proceedings of the previous workshop [1] However, since then we have adopted a new principle relating to the fermion mass terms in the Lagrangian The mass term is ‘factorised’ and what we call the ‘frame field’ is introduced into the covariant derivative The presence of the frame field in the resultant ‘extended covariant derivative’ has a remarkable effect: it gives rise to mass terms for the bosons mediating the interactions and also to the gravitational Lagrangian Originally included as a mass term for the fermions, the frame field ultimately is connected to bosonic mass and gravity This connection does not require symmetry breaking and the Higgs-Kibble mechanism
TL;DR: In this paper, a scenario in which the electroweak symmetry is spontaneously broken by an $SU(4)$ technicolor gauge interaction which also manages to break itself completely.
Abstract: We propose a scenario in which the electroweak symmetry is spontaneously broken by an $SU(4)$ technicolor gauge interaction which also manages to break itself completely. The technicolor gauge bosons and technifermions are not confined by the technicolor force, but get large masses. Starting with a single technidoublet, one emerges with a complete standard model family of technifermions after the symmetry breaking is complete. This suggests a broad new avenue for model building. A few variations on the theme are mentioned.
TL;DR: In this article, the interplay between electroweak fermion-number nonconserving processes at high temperatures, neutrino masses and an associated scale of B-L breaking of order 1 TeV can be compatible both with particle physics and cosmology.