Showing papers on "Elementary particle published in 1977"
TL;DR: In this paper, the authors explore the consequences of the assumption that the direct and induced weak neutral currents in an SU(2) gauge theory conserve all quark flavors naturally, i.e., for all values of the parameters of the theory.
Abstract: We explore the consequences of the assumption that the direct and induced weak neutral currents in an $\mathrm{SU}(2)\ensuremath{\bigotimes}\mathrm{U}(1)$ gauge theory conserve all quark flavors naturally, i.e., for all values of the parameters of the theory. This requires that all quarks of a given charge and helicity must have the same values of weak ${T}_{3}$ and ${\stackrel{\ensuremath{\rightarrow}}{T}}^{2}$. If all quarks have charge +2/3 or -1/3 the only acceptable theories are the "standard" and "pure vector" models, or their generalizations to six or more quarks. In addition, there are severe constraints on the couplings of Higgs bosons, which apparently cannot be satisfied in pure vector models. We also consider the possibility that neutral currents conserve strangeness but not charm. A natural seven-quark model of this sort is described. The experimental consequences of charm nonconservation in direct or induced neutral currents are found to be quite dramatic.
1,203 citations
TL;DR: In this paper, the Weinberg angle is determined to be 3.8 times the fine-structure constant for fractionally charged quarks, which coincides with the prediction of Georgi and Glashow in their unified SU(5) gauge model.
Abstract: The unified model for all elementary-particle forces recently proposed by us is discussed in detail. Starting with a nonlinear fermion Lagrangian of the Nambu-Jona-Lasinio type and imposing the massless conditions of Bjorken on vector fields, we construct an effective Lagrangian which combines the unified guage theory of Weinberg and Salam for the weak and electromagnetic interactions of leptons and quarks and the asymptotically free gauge theory of Gross, Wilczek, and Politzer for the strong interaction of quarks. The photon, weak vector bosons, and Higgs scalars appear as composites of lepton-antilepton or quark-antiquark pairs, while the color-octer gluons appear as composites of quark-antiquark pairs. As a result, the Weinberg angle is determined to be ${sin}^{2}{\ensuremath{\theta}}_{W} = \frac{3}{8}$ for fractionally charged quarks, which coincides with the prediction of Georgi and Glashow in their unified SU(5) gauge model. The gluon coupling constant is also determined to be 8/3 times the fine-structure constant. The masses of the weak vector bosons and physical Higgs scalars are related to those of leptons and quarks. We also propose a unified spinor-subquark model in which the gauge bosons and Higgs scalars as well as leptons and quarks are all composites of subquarks of spin 1/2. In such a model, we predict, among other things, the mass of the charged weak vector bosons to be approximately $\sqrt{3}$ times the subquark mass. From these results, we strongly suggest that there exist much heavier leptons and/or quarks whose masses reach or go beyond the weak-vector-boson masses or that there exist heavy subquarks whose pair-production threshold lies very close to the weak-vector-boson masses.
185 citations
01 Feb 1977
TL;DR: In this paper, a graphical and tabular compilation of atomic and molecular cross sections of interest to controlled thermonuclear research is presented, where the cross sections are tabulated and graphed as a function of energy for collision processes involving heavy particles, electrons, and photons with atoms and ions.
Abstract: Presented is an evaluated graphical and tabular compilation of atomic and molecular cross sections of interest to controlled thermonuclear research. The cross sections are tabulated and graphed as a function of energy for collision processes involving heavy particles, electrons, and photons with atoms and ions. Also included are sections on data for particle penetration through macroscopic matter, particle transport properties, particle interactions with surfaces, and pertinent charged particle nuclear cross sections and reaction rates. In most cases estimates have been made of the data accuracy.
138 citations
TL;DR: In this paper, a model for the spontaneous breaking of chiral symmetry is proposed, which predicts the form of the spin-dependent structure functions of deep inelastic lepton scattering.
Abstract: The representation mixing induced by the spontaneous breaking of chiral symmetry is a spatially varying phenomenon. A model for this effect predicts the form of the spin-dependent structure functions of deep inelastic lepton scattering and leads to the relation 1-..cap alpha../sub A/1(0) =2(1-..cap alpha../sub rho/(0)).
121 citations
TL;DR: In this article, the start of a third yrast discontinuity at $I=38$ is indicated and candidates for the $I = 40$ state are suggested and possible causes of the discontinuity are discussed.
Abstract: Discrete yrast transitions from states with spins up to $I=38$ have been observed in $^{158}\mathrm{Er}$ via the reaction $^{122}\mathrm{Sn}(^{40}\mathrm{Ar}, 4n\ensuremath{\gamma})$ In addition to the pronounced backbend at $I=14$ and the upbend at $I=28$ previously known, the start of a third yrast discontinuity at $I=38$ is indicated Candidates for the $I=40$ state are suggested and possible causes of the yrast discontinuity are discussed
94 citations
TL;DR: All of the experimental evidence for and against the existence of free, physical quarks from cosmic rays, particle accelerators, and stable matter is reviewed in this paper, with the exception of Niobium pellets of third-integral residual charge.
Abstract: All of the experimental evidence for and against the existence of free, physical quarks from cosmic rays, particle accelerators, and stable matter is reviewed. There is no evidence for the existence of free quarks of fractional charge save for one recent report of niobium pellets of third-integral residual charge. The related searches for quarks of integral charge, for free magnetic monopoles, tachyons, dyons, and other postulated, stable elementary objects are also reviewed. Although some puzzling observations are noted, there is no firm evidence for any of these particles.
90 citations
TL;DR: Theoretical arguments for the existence of intermediate vector bosons in high-energy nucleon−anti-nucleon collisions are reviewed and the anticipated properties are enumerated in this article.
Abstract: Prospect for the discovery of the charged and neutral intermediate vector bosons in high-energy nucleon---(anti)nucleon collisions are examined. Theoretical arguments for the existence of intermediate bosons are reviewed and the anticipated properties are enumerated. Detailed calculations based on the Drell-Yan model are presented for the production cross sections and for the distributions of decay products. On the basis of these computations the requirement r experimental detectors are assessed.
85 citations
01 Jan 1977
TL;DR: In this paper, the authors presented seven lectures on deep hadronic structure, functional methods and perturbation theory, gauge theories, quantum chromodynamics, neutrino physics electron--positron interactions, the current weak current, and beyond charm.
Abstract: There are seven lectures presented on deep hadronic structure, functional methods and perturbation theory, gauge theories, quantum chromodynamics, neutrino physics electron--positron interactions, the current weak current, and beyond charm. (JFP)
75 citations
TL;DR: In this article, an extension of the gauge theory of weak and electromagnetic interactions to SU(3) x U(1) was proposed, which naturally insures universality, absence of right-handed currents in µ-beta and muon decay, flavor conservation in neutral currents, etc.
Abstract: We describe an extension of the gauge theory of weak and electromagnetic interactions to SU(3) x U(1). The extended theory naturally insures universality, absence of right-handed currents in ..beta.. and muon decay, flavor conservation in neutral currents, etc.; gives good quantitative agreement with observations of neutral currents; and accounts for recently observed trimuon events.
67 citations
66 citations
TL;DR: An optical detection method for the nuclear polarization after foil excitation of such beams is described and used for a hyperfine structure quantum-beat measurement on the 14N II −2p 3p3D-state as mentioned in this paper.
Abstract: It is shown that nuclear spin polarized ion beams can be generated by ion beam surface interaction at grazing incidence. An optical detection method for the nuclear polarization after foil excitation of such beams is described and used for a hyperfine structure quantum-beat measurement on the14N II −2p 3p3D-state.
TL;DR: In this paper, the results of a Fermilab experiment using the 30-in. hydrogen bubble chamber are reported, with the main emphasis on pion production in the central region.
Abstract: Results of a Fermilab experiment using the 30- in. hydrogen bubble chamber are reported, with the main emphasis on pion production in the central region. Single-particle inclusive and semi-inclusive distributions in rapidity, Feynman x, and p/sub T//sup ts2/ for both ..pi../sup -/ and ..pi../sup +/ are presented and compared with results of other experiments. Two-particle distributions are investigated using the correlation-function formalism. The relation between inclusive and semi- inclusive correlation functions is discussed. The semi-inclusive correlation functions in rapidity are found to have short-range character compatible with the ideas of independent-cluster- emission models. Evidence for effects due to Bose-Einstein statistics of like particle is found by comparing the joint correlation function in rapidity and azimuthal angle, as well as the charge multiplicity associated with transverse momentum in the like and unlike-charge combinations. Data on the average associated transverse momentum are also presented. The inclusive and semi-inclusive three-particle distributions are presented for all charge combinations. The inclusive three- particle correlations are found to be small for events with more than four particles in the final state. Two independent ways were found in which three-particle densities can be expresed in terms of one- two-particle densities.
TL;DR: A relativistic theory of the inclusive scattering of nuclei is given in this article, which is applicable to meson production reactions as well as to the yields of light nuclei.
Abstract: A relativistic theory of the inclusive scattering of nuclei is given. The theory is applicable to meson production reactions as well as to the yields of light nuclei. A characterization of the relativistic nuclear wave function is given and its connection to the standard wave function is explicitly shown. Counting rules are derived that allow one to simply characterize the behavior of the reaction cross sections in terms of the short-range behavior of the nucleon-nucleon force. Good agreement with experiment is achieved if the force is assumed to be due to the exchange of vector mesons with monopole form factors at each vertex. The predictions are successfully compared to several reactions.
TL;DR: In this article, the authors analyzed data taken in the CERN narrow-band neutrino and antineutrino beams with regard to the ''highy anomaly'' observed by previous experiments at Fermilab.
Abstract: We have analyzed data taken in the CERN narrow-band neutrino and antineutrino beams with regard to the ''high-y anomaly'' observed by previous experiments at Fermilab. At neutrino energies between 30 and 200 GeV, the anti ..nu.. and ..nu.. charged-current cross-section ratios and muon-inelasticity distributions disagree with the earlier results. In particular, there is no evidence for energy-dependent effects in the antineutrino data which constitute an important aspect of the alleged anomaly.
Journal Article•
TL;DR: In this article, some considerations are presented in favor of baryon number nonconservation at the elementary particle level if the strong gravitational interaction at short distances is taken into account.
Abstract: Some considerations are presented in favor of baryon-number nonconservation at the elementary particle level if the strong gravitational interaction at short distances is taken into account. A rough and unreliable estimate is given for the decay time of nuclei according to this mechanism.
01 Jan 1977
TL;DR: The creation of particles by gravitational fields is a natural consequence of quantum field theory in curved space-time as discussed by the authors, and it occurs in particle-antiparticle pairs in the models considered, and does not violate the local conservation laws.
Abstract: The creation of particles by gravitational fields is a natural consequence of quantum field theory in curved space-time. It occurs in particle-antiparticle pairs in the models considered, and does not violate the local conservation laws. This process has important consequences in cosmological and black hole metrics.
05 Sep 1977
TL;DR: In this paper, the local rate of massless particle production in a weakly anisotropic homogeneous cosmological model and a weak inhomogeneous gravitational field was calculated in which the condition q/sup i/q/sub i/> or = 0 is satisfied for the wave vectors of the nonzero Fourier components in second order perturbation theory.
Abstract: The local rate of production of massless particles is calculated in a weakly anisotropic homogeneous cosmological model, and also in a weak inhomogeneous gravitational field, in which the condition q/sup i/q/sub i/> or =0 is satisfied for the wave vectors of the nonzero Fourier components in second-order perturbation theory The rate turns out to be proportional to the local values of the invariants of the curvature tensor
TL;DR: In this article, the equivalence of the sine-Gordon and Thirring models on the basis of the short-distance behavior in the massive thirring model was investigated and a new additive renormalization effect originating from the occurrence of non-leading mass singularities in the spinor vacuum expectation values was found.
Abstract: We investigate the equivalence of the sine-Gordon and Thirring models on the basis of the short-distance behavior in the massive Thirring model. We find that for $\mathrm{dim}\overline{\ensuremath{\psi}}\ensuremath{\psi}\ensuremath{\ge}1$ there is a new additive renormalization effect originating from the occurrence of nonleading mass singularities in the spinor vacuum expectation values. In the sine-Gordon language this effect makes its appearance as a "cumulative" mass effect. It leads to a breakdown of the naive variational method.
Journal Article•
TL;DR: In this paper, the possibility of searching for W bosons in underwater experiments with the aid of the resonant reaction anti-nu../sub e/-e/sup -/..-->..W/sup-/..>
Abstract: The possibility is discussed for searching for W bosons in underwater experiments with the aid of the resonant reaction anti ..nu../sub e/+e/sup -/..-->..W/sup -/..-->..hadrons. The resonance production of W bosons manifests itself as a narrow peak in the energy spectrum of the underwater nuclear-electromagnetic cascades. For W-boson masses 30--100 GeV (resonant antineutrino energies 9 x 10/sup 14/-1 x 10/sup 16/ eV) the resonant effect should exceed by more than one order of magnitude the background due to the nonresonant neutrino events.
TL;DR: In this article, it was shown that if the exchange of charged Higgs bosons as recently proposed by Weinberg is violated, then the neutron electric dipole moment is not affected by this additional interaction.
Abstract: We show that if $\mathrm{CP}$ violation occurs through the exchange of charged Higgs bosons as recently proposed by Weinberg, then $P$ (and hence $\mathrm{CP}$) is also violated through the exchange of neutral Higgs bosons. Whereas ${K}_{L}\ensuremath{\rightarrow}2\ensuremath{\pi}$ is not affected by this additional interaction, the neutron electric dipole moment is, and its value can be well within experimental limits.
TL;DR: In this article, the pion and nucleon total and differential cross sections are calculated in a nuclear fireball, where the total and the differential cross section shows structure due to the decay of resonances.
Abstract: Thermal equilibrium among hadrons in a nuclear fireball is assumed. Pion and nucleon total and differential cross sections are calculated. The pion differential cross section shows structure due to the decay of resonances. For neutron rich projectile-target combinations there is a net conversion of neutrons to protons.
TL;DR: In this article, an energetic electron layer is found immediately adjacent to and outside of the magnetopause surface along the distant magnetotail (−40 ≲ X_(SM) ≲ −15 R_E).
Abstract: An energetic electron layer is found immediately adjacent to, and outside of, the magnetopause surface along the distant magnetotail (−40 ≲ X_(SM) ≲ −15 R_E). The layer has been detected using Caltech instrumentation aboard the earth-orbiting spacecraft IMP-8 and is observed for electrons with energies E ≳ 200 keV. The present study shows that such electrons form a layer ∼ 3 R_E thick and are strongly streaming in a well-ordered pattern, especially along the dusk magnetopause. The energy dissipation implied by the persistent flow may be a direct indication of nearly continuous magnetic merging at or near the magnetopause.
TL;DR: In this paper, it is shown that the standard four-quark model of weak interactions is inconsistent with observed anomalies in ν, ν -interactions. And the effect of charmed particles production is estimated within the model developed.
TL;DR: In this article, it was shown that neither the phase space spectrum modified by the proton-proton final state interaction nor the spectrum corresponding to sequential decay through the /sup 5/Li ground state have shapes consistent with the data.
Abstract: The particle decay of the ground state of /sup 6/Be was observed following population in the /sup 6/Li(/sup 3/He,t)/sup 6/Be reaction. The ..cap alpha.. particle decay spectrum corresponds to the ordinary three body phase space shape for energies above about 100 keV in the /sup 6/Be center-of-mass system. At lower energies the relative yield exceeds the available phase space. It is shown that neither the phase space spectrum modified by the proton-proton final state interaction nor the spectrum corresponding to sequential decay through the /sup 5/Li ground state have shapes consistent with the data. The enhanced yield of low energy ..cap alpha.. particles is not accounted for by either process.
TL;DR: In this paper, the results of the nonrelativistic application of the quark-confining string model to the study of $\ensuremath{\psi}$ spectroscopy were reported.
Abstract: We report the results of the nonrelativistic application of the quark-confining string model to the study of $\ensuremath{\psi}$ spectroscopy. This string model is defined by a relativistic-invariant, gauge-invariant, and reparametrization-invariant action describing quarks interacting with color SU(3) gauge fields. The model has no gluonic degrees of freedom, but has instead string degrees of freedom. Quark masses and the quark-gluon coupling constant are the only parameters of the model. In the Schr\"odinger limit and in the absence of light quarks, the longitudinal modes of the quark-antiquark pair and the rotational modes of the string for a meson reduce to the charmonium model with a linear potential. String vibrations, which are absent in the charmonium model, provide additional levels. They start coming in at around 4.0 GeV; the density of states increases as an exponential function of the mass. The two lowest vibrational levels in the ${e}^{+}{e}^{\ensuremath{-}}$ channel have energies at 4.0 GeV and 4.4 GeV. Relativistic corrections are estimated to be small for the low-lying states so that the Schr\"odinger approximation is justified. We consider this application to $\ensuremath{\psi}$ spectroscopy as a test of the model.
TL;DR: In this article, the authors describe stable field configurations of two scalar fields ϑ and φ (x,y,z,t) and show that the structures P=1 and P=−1 are related by mirror symmetry.
Abstract: This paper describes stable field configurations of two scalar fields ϑ (x,y,z,t) and φ (x,y,z,t). The field configurations follow from a simple least action principle based on an energy density which is a function of ϑ, φ, and their first derivatives. The description is Lorentz‐invariant. The structures are of a stringlike type and are characterized by several integers. It is shown, that the simplest closed strings, described by the integers N=1, M=1, P±1, are stable. The structures P=1 and P=−1 are related by mirror symmetry. Three constants enter in the basic action principle: a length l, a constant E with the dimension of energy time length, and a dimensionless parameter γ. All properties of these field configurations have discrete values, which is a direct consequence of the nonlinearity of the basic expression for the energy density. An attempt is made to identify these structures with elementary particles, the electron and the positron in the simplest case P=1 and P=−1. To this aim, the total energy of the field structures is equated to the rest energy of the particles. The constants E, l, and γ are related to the fundamental physical constants h, m, e. The model proposed represents a classical field structure with quantized properties.
TL;DR: Significant dynamical correlations increasing with incident beam momentum and short-ranged in nature are observed in proton-nucleus interactions as mentioned in this paper, showing that the correlation increases with the incident beam velocity.
Abstract: Significant dynamical correlations increasing with incident beam momentum and short-ranged in nature are observed in proton-nucleus interactions.
TL;DR: In this article, the 1s level is shifted by 44 ± 5 eV by the (attractive) strong interaction, and the natural 1 s level width is 42 ± 14 eV.
TL;DR: The treatment of the complex structure of electrons includes a mathematically complete solution of the Nrepresentability problem, enumeration of some of the known necessary conditions for N-representability, some numerical calculations, and some possible lines for further research.
Abstract: The treatment of the complex structure of electrons includes a mathematically complete solution of the N-representability problem, enumeration of some of the known necessary conditions for N-representability, some numerical calculations, and some possible lines for further research. (JFP)
TL;DR: In this paper, a sample of 1200 phi mesons produced in the Zweig-rule-forbidden reactions showed a flat t distribution (slope=1.7 +- 0.2 GeV/sup -2/) and a cross section suppressed by 0.0032 + - 0.0004 relative to π n.
Abstract: A sample of 1200 phi mesons produced in the Zweig-rule-forbidden reactions ..pi../sup plus-or-minus/N..-->..phiN shows a flat t distribution (slope=1.7 +- 0.2 GeV/sup -2/) and a cross section suppressed by 0.0032 +- 0.0004 relative to ..pi../sup -/p..--> omega..n. Natural-parity-exchange ..omega.. and phi production have similar t dependences, while ..omega.. and phi production by unnatural-parity exchange differ markedly. Interference between the phi and the underlying K-barK S wave indicates substantial nucleon-spin incoherence between the amplitudes for phi and S-wave production.