Showing papers on "Explicit symmetry breaking published in 1978"
TL;DR: In this article, the authors analyzed the symmetry breaking pattern of an SU(2) U(1) gauge model with two Higgs doublets and found the phenomenon of spin-zero leptons to be a very general one and obtained a solution previously obtained by one of them as a limiting case.
Abstract: We analyze fully the pattern of symmetry breaking of an SU(2) \ifmmode\times\else\texttimes\fi{} U(1) gauge model with two Higgs doublets. We find the phenomenon of spin-zero leptons to be a very general one, and obtain a solution previously obtained by one of us as a limiting case.
860 citations
TL;DR: In this article, it was shown that the 1/N expansion of the SU(N) thirring model vanishes in the two-dimensional XY model.
270 citations
TL;DR: In this article, an extension of the SO(10) and SU(5) models is presented, and the renormalized value of sin2θw is approximately 1 4.
210 citations
TL;DR: In this paper, the first 4 dimensions are a flat Minkowskian space-time, while the D others are a compact, space-like manifold of small size.
134 citations
TL;DR: In this paper, the theory of two chemisorbed atoms has been hindered by the very low symmetry of the problem, and a variety of elaborate many-body techniques have been successfully applied to these systems; there are several excellent recent reviews.
Abstract: Progress in the development of the theory of two chemisorbed atoms has been hindered by the very low symmetry of the problem. Mono-layers of adatoms are simplest since they have the full two-dimensional symmetry of the substrate. Going to a (2 × 1) or a (2 × 2) adlayer, which doubles the size of the surface primitive cell, quadruples the size of a secular matrix, raising computer time even more. At the other end of the scale, a single adatom (in a symmetric site) will at least have the point symmetry of the substrate. With jellium as a substrate, this increases to full rotational and translational symmetry. Conserved quantities (“good quantum numbers”), which make calculations simpler, are associated with these symmetries. As a result, a variety of elaborate many-body techniques have been successfully applied to these systems; there are several excellent recent reviews.1,2 For two adatoms on a surface, there is little or no symmetry, typically just a twofold rotation or mirror plane (often leadin...
104 citations
TL;DR: In this article, a new symmetry breaking mechanism for low mass negative parity hyperons was proposed, where a pair of orbital states which are degenerate when all three quarks have the same mass splits up when the quarks had different masses.
91 citations
54 citations
41 citations
38 citations
TL;DR: In this article, a supersymmetric theory for a strong f- plus a weak g-graviton, together with their accompanying massive gravitinos, was constructed by gauging the graded OSp(2, 2, 1) × OSp2,2, 1 ) structure.
38 citations
TL;DR: In this paper, the authors discuss the case of an O(N)-symmetric theory whose symmetry is broken by a quadratic term which produces two different masses (correlation lengths) one associated with M components and one with N − M. This theory describes physical systems having a bicritical point.
TL;DR: In this article, the general connections between Stokes and anti-Stokes cross sections are examined on the basis of the time-reversal symmetry of light-scattering experiments.
Abstract: The general connections between Stokes and anti-Stokes cross sections are examined on the basis of the time-reversal symmetry of light-scattering experiments. The corresponding symmetry properties of the transition rates, susceptibilities and Green functions which occur in light-scattering theory are reviewed. A rigorous Stokes-anti-Stokes connection formula is derived and compared with an approximation in common use.
01 Jan 1978
TL;DR: In this paper, the case of all irreps (irreducible representations) on the reals of the 32 point groups is treated, and the authors reduce the study of the 153 equivalence classes of irreps to few cases.
Abstract: We treat here the case of all irreps (irreducible representations) on the reals of the 32 point groups. For each point group these irreps are irreps with wave vecor k = 0 of the corresponding space groups. Landau model of second order phase transition can be applied to those irreps with no third degree invariants : one has to look for minima of a bounded below fourth degree polynomial which is not minimum at the origin, and determine the little groups (= isotropy groups) of these minima ; they are the subgroups into which the symmetry can be broken in the transition. By an efficient strategy we reduce the study of the 153 equivalence classes of irreps to few cases (6). Moreover we do not need to study the minima of invariant polynomials, we simply apply Morse theory to find the possible little groups of minima.
TL;DR: In this article, the broken symmetry concept of Goldstone is applied to an inhomogeneous fluid and specific calculations are performed for the liquid-vapor interface of a simple fluid, where the collective variable associated with the breaking of spatial symmetry is the normal displacement of the interface from its equilibrium position.
Abstract: The broken symmetry concept of Goldstone is applied to an inhomogeneous fluid. Specific calculations are performed for the liquid–vapor interface of a simple fluid. The collective variable associated with the breaking of spatial symmetry is the normal displacement of the interface from its equilibrium position. The static correlation function of this variable exhibits long‐range order. Associated with this symmetry breaking variable are propagating modes. The dispersion relation for these surface modes is found to be identical with the hydrodynamic result for capillary waves.
TL;DR: In this paper, a method for determining the isotropy subgroups of an arbitrary, irreducible representation of SO(3) is given, explicitly worked out for low-dimensional representations.
Abstract: A method is given for determining the isotropy subgroups of an arbitrary, irreducible representation of SO(3). These subgroups are explicitly worked out for low‐dimensional representations. As an application of these results we contruct the most general, renormalizable, SO(3) invariant Higgs potentials for these representations, determine the local minima of the potentials and discuss patterns of spontaneous symmetry breaking.
TL;DR: In this article, the problem of developing a consistent perturbation theory for a Fermi system in the case in which the unperturbed system exhibits dynamical symmetry breaking is discussed, by using collective coordinate methods.
TL;DR: In this paper, the formalisms of spontaneous symmetry breaking and of nonlinear Lagrangians are reviewed, with emphasis on the relationships between the two, and the Weinberg-Salam model is applied to the physical fields and their explicit transformation laws under finite group action.
Abstract: The formalisms of spontaneous symmetry breaking and of the theory of nonlinear Lagrangians are reviewed, with emphasis on the relationships between the two. The former is applied to the Weinberg-Salam model, in which case the physical fields and their explicit transformation laws under finite group action are exhibited. The latter is illustrated through the example of the graded Lie group OSp(1/4). Locally covariant fields and derivatives are then constructed, and invariant terms are written down which contain the Lagrangian of supergravity.
TL;DR: In this article, all differences between the leptons e, μ and τ arise from spontaneous symmetry breaking, which leads to conservation of multiplicative rather than additive lepton number in the standard gauge model.
TL;DR: In this article, the authors traced the historical origin of these prejudicial procedures and traced their historical origin, while presenting an alternative that restores an unbiased treatment of improper spacetime symmetries.
Abstract: Mathematical tradition has it that transformations characterized by a negative Jacobian determinant are referred to as improper transformations. The symmetry of a physical object corresponding to such an improper transformation becomes an improper symmetry. Improper symmetries have been successfully used for the purpose of crystal symmetry. The extension of these purely spatial symmetries to the domain of spacetime has led to a prejudicial use of light-cone properties, thus affecting adversely an unbiased symmetry classification. We pinpoint these prejudicial procedures and trace their historical origin, while presenting an alternative that restores an unbiased treatment of improper spacetime symmetries. The applications discussed relate to recent developments in the symmetry classification of magnetic crystals and to the extension of Neumann's principle to the time domain.
TL;DR: In this article, the authors considered the case of potentials with continuous symmetry, assuming that the spectrum of small oscillations around classical vacua has no zero modes besides the ones due to spontaneous symmetry breaking.
TL;DR: In this article, a rotational-vibrational symmetry correlation scheme between an intermediate reaction complex and the corresponding reactant or product fragments is proposed, focusing on the symmetry of the eigenfunctions at both limits: the fragments at infinite separation and the complex as a molecule.
Abstract: A rotational–vibrational symmetry correlation scheme between an intermediate reaction complex and the corresponding reactant or product fragments is proposed. The emphasis is on the symmetry of the eigenfunctions at both limits: the fragments at infinite separation and the complex as a molecule. Because of the introduction of rotation, the permutation‐inversion group rather than the usual point group is taken as the symmetry group of the rotating and vibrating fragments and its symmetry species are correlated to the point group species of the complex. Correlations are presented for the systems AB–AB, A2–A2, B2–A2, A–A2, and B–A2 at various symmetric configurations without any consideration given to the energetics of the reactions. This general approach makes the scheme useable for a variety of reactions. It also provides the building‐up principle for the rotation–vibration states of polyatomic molecules. Application to the O2–O2 dimer formation is discussed.
TL;DR: In this paper, a perturbation theory for two-dimensional field theories with spontaneous symmetry breaking at the classical level is discussed, where the formalism in terms of currents is employed to restore the continuous symmetries which, according to general theorems, cannot be spontaneously broken at the full quantum level.
TL;DR: In this article, it was shown that spontaneous symmetry breaking may provide a gauge hierarchy of any desired magnitude within the one-loop approximation of a single-input-one-out (SISO) model.
TL;DR: In this article, the authors show how the additional symmetry of a nonlinear equation helps to reduce the determining equations for some of the solutions of periodic solutions of systems, which have the so-called property E, as introduced by Hale [ 1, 21].
TL;DR: In this paper, a method for the determination of the symmetry of first-order vectors in Hartree-Fock perturbation theory is developed, which leads to the definition of symmetry-adapted basis vectors to be employed at first order in the perturbations, and shows that computer time can be saved, to some extent, in the calculation of second-order properties, by exploiting molecular symmetry.
Abstract: A method for the determination of the symmetry of first-order vectors in Hartree–Fock perturbation theory is developed. This leads to the definition of symmetry-adapted basis vectors to be employed at first order in the perturbation. It is shown that computer time can be saved, to some extent, in the calculation of second-order properties, by exploiting molecular symmetry. Specific examples are given for methane, ammonia, and water.
TL;DR: In this paper, it was shown that the breaking of chiral symmetry is dynamical and the vacuum is unique, contrary to the arguments by Kogut and Susskind.
TL;DR: In this article, the Coulomb interaction alone was used to explain strong isospin mixing in 8Be, 12C, and 16O matrix elements, and it was shown that contributions from charge symmetry breaking nuclear interactions are small.
Abstract: We consider the well-known cases of strong isospin mixing in8Be,12C, and16O. We show that, contrary to some previous claims which invoke the need for a charge symmetry breaking nuclear interaction, (i) the isospin mixing matrix elements can be explained by the Coulomb interaction alone and (ii) contributions from charge symmetry breaking nuclear interactions are small.
TL;DR: In this paper, the authors show that transformation to the expanding or Rindler coordinate frames in the theory of a self-interacting massless scalar field can lead to spontaneous breaking of conformal symmetry and changing of the space-time geometry.
TL;DR: In this paper, the authors make an analysis of symmetry in respect of the effects associated with rotation of the polarization plane of light in crystals, namely, the optical activity, magnetic rotation and polar optical activity effect.
Abstract: The author makes an analysis of symmetry in respect of the effects associated with rotation of the polarization plane of light in crystals, namely, the optical activity (symmetry ∞), magnetic rotation (symmetry ∞/m; Faraday effect), and polar optical activity effect (symmetry ∞mm; antisymmetric part of the second-rank axial tensor). The latter effect is being predicted. Using tables of irreducible representations of the point symmetry groups with geometrized bases, including the invariants described by second-rank axial tensors, the author analyses the phase transitions induced solely by optical activity (symmetry ∞2; 14 cases) and optical activity coupled with spontaneous polarization (symmetry ∞mm; 16 cases). A review is given of the work on electrogyration effects (spontaneous and forced), which consist in optical activity induced by an electric field (axial tensors of the third and fourth ranks). There is a discussion of the features of electrogyration during phase transitions in Rochelle salt, trigly...