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in subjects: "Symmetry"

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Two exercises in supersymmetry: a low-energy supergravity model and free string field theory

The new features of a supersymmetric standard model in the presence of heavy families are studied. The minimal set of Higgs fields, the desert between the electroweak and the grand unification scale and perturbative values of the dimensionless parameters throughout this region are assumed. Using the numerical as well as the approximate analytic solution of the renormalization group equations, the evolution of all the parameters of the theory are studied in the case of large Yukawa couplings for… more

Date: September 1, 1986

Creator: Preitschopf, C.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Radiative corrections in SU/sub 2/ x U/sub 1/ LEP/SLC

We show the sensitivity of various experimental measurements to one-loop radiative corrections in SU/sub 2/ x U/sub 1/. Models considered are the standard GSW model as well as extensions of it which include extra quarks and leptons, SUSY and certain technicolor models. The observation of longitudinal polarization is a great help in seeing these effects in asymmetries in e/sup +/e/sup -/ ..-->.. ..mu../sup +/..mu../sup -/, tau/sup +/tau/sup -/ on Z/sup 0/ resonance. 25 refs., 22 figs., 10 tabs.

Date: June 1, 1985

Creator: Lynn, B. W.; Peskin, M. E. & Stuart, R. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Physics Division Summary Report

The use and operation of the 4.5-Mev Van de Graaff generator ts descrtbed. Sputtering experiments were conducted by bombarding single crystals of electrolytic copper wtth deuterons with energies of 0.8 to 2.5 Mev. The experimental results are discussed on the basis of existing sputtering theories. The kinetic-energy distribution and Boltzmann "temperatures" of most of the fragments of cyanogen under electron impact were determined. A lower limit of 0.05 ev for this temperature'' was also determ… more

Date: January 1, 1962

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Quarks and gluons in hadrons and nuclei

These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of th… more

Date: December 1, 1989

Creator: Close, F. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Beta-decay beyond the standard model

We discuss possible sources of new interactions in beta-decay and the role of beta-decay experiments in obtaining information on them. 46 refs.

Date: January 1, 1989

Creator: Herczeg, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electronic and structural properties of metallic microclusters

The first part of this thesis presents a first-order pseudopotential calculation at T=O of the total energy of small sodium clusters of size N<800. The calculation is based on a local-pseudopotential scheme and local-density correlation and exchange. A temperature-size (T-N) phase-diagram is then derived using the T=O results and Lindemann's criterion for melting. The phase-diagram contains three regions of stability: (1) a liquid (jellium) phase at temperatures above the melting line T{sub M}(… more

Date: April 1, 1992

Creator: Maiti, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Ultrafast gated intensifier design for laser fusion x-ray framing applications

A major challenge for laser fusion is the study of the symmetry and the hydrodynamic stability of imploding fuel capsules. Streaked x-radiography, in one space and one time dimension, does not provide sufficient information. Two (spatial) dimensional frames of 10 to 100 ps duration are required with good image quality, minimum geometrical distortion (approximately 1%), dynamic range greater than 1000 and greater than 200 x 200 pixels. A gated transmission line imager (TLI) can meet these requir… more

Date: November 1, 1983

Creator: Price, R.H.; Wiedwald, J.D.; Kalibjian, R.; Thomas, S.W. & Cook, W.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Axisymmetric instability in a noncircular tokamak

The stability of dee, inverse-dee and square cross section plasmas to axisymmetric modes has been investigated experimentally in Tokapole II, a tokamak with a four-null poloidal divertor. Experimental results are closely compared with predictions of two numerical stability codes - the PEST code (ideal MHD, linear stability) adapted to tokapole geometry and a code which follows the nonlinear evolution of shapes similar to tokapole equilibria.

Date: October 1, 1979

Creator: Lipschultz, B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Spontaneous breaking of supersymmetry

There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. appr… more

Date: December 1, 1981

Creator: Zumino, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Nuclear Physics Laboratory annual report, University of Washington April 1992

This report contains short discusses on topics in the following areas: astrophysics; giant resonances and photonuclear reactions; nucleus-nucleus reactions; fundamental symmetries; accelerator mass spectrometry; medium energy nuclear physics; ultra-relativistic heavy ion collisions; cluster fusion; instrumentation; van de graaff accelerators and ion sources; and computer data acquisition systems. (LSP)

Date: January 1, 1992

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Symmetry, stability, and diffraction properties of icosahedral crystals

In a remarkable experiment on an Mn-Al alloy, Shechtman et al. observed a diffraction spectrum with icosahedral symmetry. This is inconsistent with discrete translational invariance since the symmetry includes a five-fold axis. In this paper, it is shown that the crystallography and diffraction pattern can be described by a six-dimensional space group. The crystal structure in 3d is obtained as a cut along a 3d hyperplane in a regular 6d crystal. Displacements of the 6d crystal along 6 orthogon… more

Date: January 1, 1985

Creator: Bak, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Physics issues for the next linear collider

This article surveys the physics issues to be studied at future e{sup +}e{sup {minus}} colliders, especially in the energy region below 500 GeV. Particular emphasis is given to standard model studies -- precision measurements of the dynamical properties of W bosons and top quarks -- as well as the search for evidence of the Higgs sector.

Date: April 1, 1992

Creator: Peskin, M.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Introduction to conformal field theory and string theory

These lectures are meant to provide a brief introduction to conformal field theory (CFT) and string theory for those with no prior exposure to the subjects. There are many excellent reviews already available, and most of these go in to much more detail than I will be able to here. 52 refs., 11 figs.

Date: December 1, 1989

Creator: Dixon, L.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Quarks and gluons in hadrons and nuclei

Date: January 1, 1989

Creator: Close, F. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Proton decay: 1982

Employing the current world average ..lambda../sub MS/ = 0.160 GeV as input, the minimal Georgi-Glashow SU(5) model predicts sin/sup 2/theta/sub W/(m/sub W/) = 0.214, m/sub b//m/sub tau/ approx. = 2.8 and tau/sub p/ approx. = (0.4 approx. 12) x 10/sup 29/ yr. The first two predictions are in excellent agreement with experiment; but the implied proton lifetime is already somewhat below the present experimental bound. In this status report, uncertainties in tau/sub p/ are described and effects of… more

Date: March 4, 1982

Creator: Marciano, William J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Inductive currents in an rf driven plasma

Inductive effects are included in a self-consistent current drive model for axisymmetric tokamak plasmas used in the two-dimensional current drive/MHD equilibrium code, RIP. Previous simulations of current driven equilibria allowed for the steady-state calculation of bootstrap and RF currents. The addition of an inductive current is applied to enhance accurate design and interpretation of tokamak experiments. A convenient expression for the ohmic resistance in a tokamak plasma is derived to aid… more

Date: August 1, 1991

Creator: Kinsey, J. & Ehst, D.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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OMEGA: a short-wavelength laser for fusion experiments

The OMEGA, Nd:glass laser facility was constructed for the purpose of investigating the feasibility of direct-drive laser fusion. With 24 beams producing a total energy of 4 kJ or a peak power of 12 TW, OMEGA is capable of nearly uniform illumination of spherical targets. Six of the OMEGA beams have recently been converted to short-wavelength operation (351 nm). In this paper, we discuss details of the system design and performance, with particular emphasis on the frequency-conversion system an… more

Date: January 1, 1983

Creator: Soures, J. M.; Hutchison, R. J.; Jacobs, S. D.; Lund, L. D.; McCrory, R. L. & Richardson, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Research at LAMPF

During the past decade, both the science program and the experimental facilities at LAMPF have undergone some significant changes. This report is a concise description of the current research initiatives and of new directions being proposed for the future research program at LAMPF. Traditionally the LAMPF physics program has explored nuclear systems with hadronic probes: pions, protons, and neutrons. In recent years the exploitation of the intense lepton beams -- neutrinos and muons -- at LAMPF… more

Date: February 1, 1992

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Z yields jets+. gamma. as a signal for R-parity violation

Supersymmetric models with explicit R-parity violation can induce new rare decay modes of the Z boson into single supersymmetric particles. Here, the rate and signature for one such decay, Z {yields} {tilde {upsilon}} {gamma}, is examined, where it is found that the rate is at least an order of magnitude smaller than that for the process Z{yields} H{gamma}, even with larger values of the R-parity violating couplings.

Date: February 1, 1992

Creator: Hewett, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Non-rigid molecular group theory and its applications

The use of generalized wreath product groups as representations of symmetry groups of nonrigid molecules is considered. Generating function techniques are outlined for nuclear spin statistics and character tables of the symmetry groups of nonrigid molecules. Several applications of nonrigid molecular group theory to NMR spectroscopy, rovibronic splitting and nuclear spin statistics of nonrigid molecules, molecular beam deflection and electric resonance experiments of weakly bound Van der Waal c… more

Date: June 1, 1982

Creator: Balasubramanian, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Symmetry Tests in Hadronic Systems

A parallel session of the conference was devoted to papers and discussions of symmetries in hadronic systems.

Date: January 1, 1992

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutrino masses and mixings - an SPVAT analysis

The connection between the form of the neutrino mass matrix and the problem of family symmetry is discussed. 16 references.

Date: January 1, 1984

Creator: Goldman, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Exotic signatures from supersymmetry

Minor changes to the standard supersymmetric model, such as soft flavor violation and R parity violation, cause large changes in the signatures. The origin of these changes and the resulting signatures are discussed. 15 refs., 7 figs., 2 tabs.

Date: August 1, 1989

Creator: Hall, L. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Determination of nonaxisymmetric equilibrium

The Princeton Equilibrium Code is modified to determine the equilibrium surfaces for a large aspect ratio toroidal system with helical magnetic fields. The code may easily be made to include any variety of modes. Verification of the code is made by comparison with an analytic solution for l = 3. Previously observed shifting of the magnetic axis with increasing pressure or with a changed externally applied vertical field is obtained. The case l = 0, a bumpy torus, gives convergence only for the … more

Date: January 1, 1980

Creator: Elkin, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department