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Pairing And Quadrupole Interactions In The Pseudo-Su(3) Shell Model., Chairul Bahri

LSU Historical Dissertations and Theses

Pseudo-SU(3) symmetry along with its simple symmetry-preserving and symmetry-breaking interactions is presented. This symmetry is a direct consequence of pseudo-spin symmetry which can be clearly seen in a single-particle shell model picture of heavy (A $\sbsp{\sim}{>}$ 100) atomic nuclei. Good pseudo-spin symmetry is shown to have its origin at a more fundamental level by considering relativistic mean field results for the strength parameters of the spin-orbit and the orbit-orbit interactions. As long as the residual interaction is a pseudo-spin scalar interaction, the many-particle extension of the single-particle picture is also expected to have,good total pseudo-spin symmetry. The quadrupole-quadrupole interaction …

Advanced Gravitational Radiation Transducers With Small Mass And Ultra-Low Temperature Squids., Ziniu Geng

LSU Historical Dissertations and Theses

The transducer and SQUID are two major components for a resonant-mass gravitational wave antenna. They must always have high sensitivity and low noise. In this work, a two-mode superconducting inductive transducer for a three-mode gravitational wave bar antenna is designed. The construction and tests of small mass resonators that form the transducer are described. The experiments and test results of commercial dc SQUIDs at ultra-low temperature are discussed in detail. Special problems arise when SQUIDs are tested at ultra-low temperature in vacuum. We address the problems and provide proper solutions. Our experiments show that the dc SQUID made by Quantum …

Energy Dependence Of Photoion Rotational Distributions., Heung-Cheun Choi

LSU Historical Dissertations and Theses

Highly resolved molecular photoionization is a topic of intense current interest due to insights it provides into fundamental scattering processes. Rotationally resolved data provide a window on the angular momentum composition of the photoelectron and the partitioning of angular momentum between the ion and photoelectron. Since the earliest rotational measurements via photoelectron spectroscopy (PES) of H$\sb2$ using resonance lamp excitation, studies have accelerated as a result of experimental innovations. However, all of these recent developments have been limited to threshold or near-threshold ionization phenomena. In order to bypass this constraint, we have employed dispersed fluorescence measurements. This strategy allows us …

Neutron Reflection Interferometry: Physical Principles Of Surface Analysis With Phase Information, Vladimir Gudkov, G. I. Opat, A. G. Klein

Faculty Publications

It is shown that the analysis of surface layers by neutron reflection interferometry is considerably enhanced by performing the reflectometry with phase information. We discuss two methods of providing such information. One method involves physically adding an extra reference layer, whose amplitude and phase are known theoretically. The other uses the Lloyd's mirror configuration, in which a directly propagating ray that interferes with the reflected ray supplies the phase information. The methods have much in common with holography.

Nous As The Ground Of Aristotle's Metaphysics?, John J. Cleary

The Society for Ancient Greek Philosophy Newsletter

This paper explores the implications of Aristotle's puzzling suggestions that the possibility of first philosophy somehow depends on whether part of the soul is separable from material body. My Conjecture1 is that for Aristotle the science of metaphysics depends on a special activity of nous that grasps die self-identical essences which are objects of first philosophy, as distinct from physics and mathematics. From Aristotle's perspective, of course, it is the existence of such essences that makes metaphysics possible, but it is arguable that without a corresponding mode of cognition this would not be a human science. It is a moot …

Numerical Study Of A High-Order Quasiconserved Quantity In The Henon-Heiles Problem, Paul Finkler, C. Edward Jones, Glenn A. Sowell

Physics Faculty Publications

Recent efforts to derive and study a quasiconserved quantity K in the Henon-Heiles problem in terms of a single set of variables are discussed. Numerical results are given, showing how the value of such a quantity varies with time and order in a power-series expansion for K in terms of monomials of the coordinates and velocities. The lowest order in the power series for K corresponds to n =4 and the highest order to n =27, so that 24 orders are included in the series. The results are compared with an earlier study by the authors [Phys. Rev. A 42, …

Cp-Odd Nucleon Potential, Vladimir Gudkov, Xiao-Gang He, Bruce H.J. Mckellar

Faculty Publications

The P-odd and CP-odd nucleon potential for different models of CP violation in the one-meson exchange approximation is studied. It is shown that the main contribution is due to the π-meson exhcange which leads to a simple one-parameter CP-odd nucleon potential.

Supersymmetry And The Tunneling Problem In An Asymmetric Double Well, Asim Gangopadhyaya, Prasanta K. Panigrahi, Uday P. Sukhatne

Physics: Faculty Publications and Other Works

The techniques of supersymmetric quantum mechanics are applied to the calculation of the energy difference between the ground state and the first excited state of an asymmetric double well. This splitting, originating from the tunneling effect, is computed via a systematic, rapidly converging perturbation expansion. Perturbative calculations to any order can be easily carried out using a logarithmic perturbation theory. Our approach yield substantially better results than alternative widely used semiclassical analyses.

In-Medium Behavior Of The Qcd ϴ Term And The Value Of Cp Violation In Nuclei, Vladimir Gudkov

Faculty Publications

The expectation value of the θ term in QCD for nuclear matter is estimated in the nucleon gas approximation. There is no significant renormalization (to an accuracy ∼10%) of the CP violation in nuclei due to the similar behaviors for the in-medium values of the θ term and quark condensates.

Studies Of Rotationally Inelastic Collisions In Argon + Hydrogen Fluoride, James J C Barrett

Doctoral Dissertations

In this dissertation we examine rotationally inelastic collisions involving an atom plus a diatom. We concentrate specifically on the Ar + HF system. In these investigations we employ a number of theoretical methods, including classical trajectories, quantum close-coupled calculations and semiclassical methods, to examine the differential cross sections in Ar + HF. We also investigate the effects of various "sudden" approximations on the scattering dynamics and the limitations of these approximations.

Through this work we were able to identify a new quantum feature in rotationally inelastic scattering. By studying the time evolution of transition amplitudes (rather than probabilities) we are …

Sign Correlations And The Mechanism For Parity Violation, Vladimir Gudkov

Faculty Publications

The problem of possible sign correlations of P-odd effects due to parity mixing on the compound nuclear stage is discussed. For an unambiguous test of the conventional model of parity violation on the compound nuclear stage, it is not enough only to measure the sign correlation of P-odd effects on some resonances, but it is necessary also to know the neutron decay amplitudes for each resonance.

Determination Of The Neutron Spin Structure Function, P. L. Anthony, R. G. Arnold, H. R. Band, H. Borel, P.E. Bosted, V. Breton, G. D. Cates, T. E. Chupp, F. S. Dietrich, J. Dunne, R. Erbacher, J. Fellbaum, H. Fonvielle, R. Gearhart, R. Holmes, E. W. Hughes, J. R. Johnson, D. Kawall, C. Keppel, S. E. Kuhn, R. M. Lombard-Nelsen, J. Marroncle, T. Maruyama, W. Meyer, Z. E. Meziani, H. Middleton, J. Morgenstern, N. R. Newbury, G. G. Petratos, R. Pitthan, R. Prepost, Y. Roblin, S. E. Rock, S. H. Rokni, G. Shapiro, T. Smith, P. A. Souder, M. Spengos, F. Staley, L. M. Stuart, Z. M. Szalata, Y. Terrien, A. K. Thompson, J. L. White, M. Woods, J. Xu, C. C. Young, G. Zapalac, E142 Collaboration

Physics Faculty Publications

The spin structure function of the neutron g₁ⁿ has been determined over the range 0.03 < x < 0.6 at an average Q² of 2 (GeV/c)² by measuring the asymmetry in deep inelastic scattering of polarized electrons from a polarized ³He target at energies between 19 and 26 GeV. The integral of the neutron spin structure function is found to be f-¹₀ gⁿ₁(x)dx = -0.022 ± 0.011. Earlier reported proton results together with the Bjorken sum rule predict f-¹₀ gⁿ₁(x)dx = -0.059 ± 0.019.

Geometrical Phases And Symmetries In Dissipative Systems, Adam S. Landsberg

WM Keck Science Faculty Papers

A geometrical phase is constructed for dissipative dynamical systems possessing continuous symmetries. It emerges as the natural analog of the holonomy associated with the adiabatic variation of parameters in quantum-mechanical and classical Hamiltonian systems. In continuous media, the physical manifestation of this phase is a spatial shift of a wave pattern, typically a translation or rotation. An illustration associated with pattern formation in fluids is provided.

Recoil Effects And Cp Violation In Neutron Scattering, Vladimir Gudkov

Faculty Publications

The problem of the imitation of CP violation in neutron scattering is discussed. The thermal motion of nuclei cannot contribute to symmetry-violating effects. The influence of the nuclear depolarization due to neutron scattering is estimated.

Resonance Absorption Of Mhd Surface Waves With Applications To The Solar Atmosphere, Guang Yang

Doctoral Dissertations

This thesis studies the physics of resonance absorption of MHD surface waves and examines the effects of velocity shear on the rate of resonance absorption. Theoretical analyses and numerical calculations demonstrate that resonance absorption of MHD surface waves is a viable mechanism for heating of the solar corona.

It is shown that resonance absorption has a very simple physical interpretation in terms of driven harmonic oscillators. This insight greatly simplifies the mathematics and allows a thorough discussion of the solar coronal heating. It is found that resonance absorption of MHD surface waves can occur rapidly enough to heat the solar …

Energetic Protons And Deuterons Emitted Following Μ⁻ Capture By ³He Nuclei, W. J. Cummings, G. E. Dodge, S. S. Hanna, B. H. King, S. E. Kuhn, Y. M. Shin, R. Helmer, R. B. Schubank, N. R. Stevenson, U. Wienands, Y. K. Lee, G. R. Mason, B. E. King, K. S. Chung, J. M. Lee, D. P. Rosenzweig

Physics Faculty Publications

Spectra of energetic protons and deuterons emitted following negative muon capture from rest in ³He have been measured for the first time. Significant capture strength is observed at high energy transfers (mμ- E_v >60 MeV) for the two-body and three-body breakup channels, indicative of the importance of nucleon-nucleon correlations and meson exchange currents in the capture process. A simple plane wave impulse approximation calculation reproduces the proton spectrum reasonably well, but underpredicts the deuteron rate at the highest energies by a large factor.

Effects Of Wind, Density, And Bathymetry On A One-Layer Southern Ocean Model, John M. Klinck

CCPO Publications

Steady solutions from a one-layer, wind-driven, primitive equation model are analyzed to determine the importance of wind forcing, pressure gradient force due to the climatological density distribution and bottom form drag on circulation in the Southern Ocean. Five simulations are discussed: three wind-forced simulations, with differing bathymetry (flat bottom, 15% bathymetry, and full bathymetry), one case with full bathymetry forced with the density-induced pressure force, and one case with full bathymetry forced by both wind and density-induced pressure gradients. The simulations presented here confirm the previous speculation (Munk and Palmen, 1951) that form drag is effective in balancing the driving …

Density Effect In Cu K-Shell Ionization By 5.1-Gev Electrons, W. E. Meyerhof, D. G. Jensen, D. M. Kawall, S. E. Kuhn, D. W. Spooner, Z. E. Meziani, D.. N. Faust

Physics Faculty Publications

We have made an absolute measurement of the Cu K-shell impact ionization cross section by 5.1-GeV electrons, which demonstrates directly a density effect predicted by Fermi in 1940. By determining the ratio of the K x-ray yield from a thin front and back layer of the target by a novel grazing emission method, we have verified the effect of transition radiation on the x-ray production, suggested by Sorensen and reported by Bak et al.

Monte Carlo Studies Of The Critical Phenomena In Carbon Monoxide Oxidation., Bing Yu

LSU Historical Dissertations and Theses

It is well established that anisotropy does not affect the critical behavior of a system in thermodynamic equilibrium undergoing a second order phase transition. We study here an anisotropic kinetic model for heterogeneous catalysis which mimics the oxidation of CO on the (110) surface of a transition metal like Pd. In this model, the oxidation process occurs at an infinite reaction rate. We mapped out the phase diagram of possible steady states for various anisotropic reaction and absorption processes as a function of the O$\sb2$/CO adsorption rate and the CO diffusion rate. The phase diagram depends upon the amount of …

Magnetic Response Of A Single, Isolated Gold Loop, V. Chandrasekhar, Richard A. Webb, M. J. Brady, M. B. Ketchen, W. J. Gallagher, A. Kleinsasser

Faculty Publications

Measurements have been made of the low-temperature magnetic response of single, isolated, micron-size Au loops. The magnetic response is found to contain a component which oscillates with the applied magnetic flux with a fundamental period of Φ₀=h/e. The amplitude of the oscillatory component corresponds to a persistent current of ≃(0.3–2.0)ev_F/L, 1 to 2 orders of magnitude larger than predicted by current theories.

Single-Electron Charging Effects In Insulating Wires, Venkat Chandrasekhar, Zvi Ovadyahu, Richard A. Webb

Faculty Publications

We present measurements of the transport properties of 0.75-μm-long, narrow, insulating indium oxide wires and rings. These devices have no apparent tunnel barriers, yet they exhibit effects similar to those found in series arrays of very small-capacitance tunnel junctions: highly nonlinear I-V characteristics and a zero-bias conductance which is periodic in a voltage applied by means of a lateral gate. These effects are due to the influence of single-electron charging on transport through localized states in the insulating regime.

Occasional Papers: On Teaching The Sciences, Janice Rowan Poley

Hollybush Series

Volume 2 of The Hollybush Series contains six essays by Glassboro State College faculty on teaching mathematics, computer science, and physics.

The editor is Janice Rowan Poley and the authors of the six essays are Janet Caldwell, Seth Bergmann, Ronald Czochor, A. Michael Berman, Karen Magee-Sauer, and Gary Itzkowitz.

Studies Of Inertio-Gravity Waves Induced By Geostrophic Adjustment Of The Atmospheric Jet Stream, Zhangai Luo

Theses (Unassigned)

Motivated by observations revealing very low frequency gravity waves throughout the lower and middle atmosphere, this thesis investigates inertio-gravity waves (IGWs) radiating from an ageostrophic jet stream assuming geostrophic adjustment to be the source mechanism. Fourier integral and Green's function techniques are employed to solve this problem. The ageostrophic components of the motion field are described by an initially unbalanced Gaussian velocity field which has been chosen to have infinite and localized zonal extents corresponding to two-dimensional (2-D) and three-dimensional (3-D) cases. The adjustment process permits the radiation of IGWs and the attainment of an induced geostrophically balanced mean circulation. …

Electro-Optical System Design For Information Processing, Clair L. Wyatt

Utah State University Faculty Monographs

This practical text/reference provides a clear,systems-oriented approach to electro-optical system design. Covering electro-optical systems that are used for information processing,the book focuses on those systems that convey information via an electro-optical beam as in remote sensing,guidance and tracking,and fiber optic and laser communication systems. With 30% more pages,this book is a greatly expanded and revised version of the author's Radiometric System Design. Part I prepares the reader to direct and monitor the design of an electro-optical system. Part II gives detailed design considerations of the major subsystems introduced in Part I. A volume in the Optical and Electro-Optical Engineering Series.

Electroweak Calculations In The Presence Of Nonperturbative Qcd Effects, Mohammad R. Ahmady

Digitized Theses

A momentum space Feynman rule is derived for the quark condensate insertion into Feynman amplitudes using the quark condensate component of the nonperturbative vacuum expectation value of the two nonlocal normal ordered quark fields. The lowest-order quark condensate component of the QCD nonperturbative quark self-energy is calculated, leading to a gauge independent dynamical component for the quark mass.;Insertion of this nonperturbative order parameter into lowest-order electroweak quark self-energies is shown to satisfy on-mass-shell gauge parameter independence only if there is no contribution from the dynamical symmetry breaking parameter {dollar}\langle\bar\Psi\Psi\rangle.{dollar} Dynamical contributions to the quark propagator, such as those from nonperturbative …

Gold & Blue, Spring/Summer 1990, St. Mary's University- San Antonio, Texas

Gold & Blue

This is the Spring/Summer 1990 edition of Gold & Blue which is St. Mary's University's official school publication.

Universal Scaling Of Nonlocal And Local Resistance Fluctuations In Small Wires, H. Haucke, S. Washburn, A. D. Benoit, C. P. Umbach, Richard A. Webb

Faculty Publications

Resistance fluctuations in small metal samples result from coherent transport of the carriers. The wave functions of the carriers extend into regions which are not accessible classically. We have directly measured the length dependence of the nonlocal magnetoresistance fluctuations in Sb and Au wires by studying regions of our samples separated from the classical current path by a distance L which varied from 3L_cphi down to 0.2L_cphi (where L_cphi is the phase coherence length for the carriers in the metal). These fluctuations decay exponentially with L/L_cphi. Measurements along the classical current paths scale more slowly …

Parametric Motion Transducer For Gravitational Wave Detectors., Odylio Denys De Aguiar

LSU Historical Dissertations and Theses

We designed, constructed, and tested (using two different low phase noise electrical pump generators) a cryogenic double-resonant parabridge motion transducer made out of niobium, whose electrical output was amplified by a two stage MESFET cryogenic amplifier. Most of the experimental results agreed well with the theoretical models, and we successfully measured the mechanical Brownian motion of this transducer. We were able to adjust the two electrical bridge resonant frequencies on top of each other at the pump frequency, allowing us to obtain an electromechanical coupling as high as 0.054. This high coupling, corresponding to an rms electric field strength of …

Time And The Physical Universe, Norman E. Ramsey

DSLS 1989-1990

(This information was taken from the Distinguished Scientist Lecture Series Program 1989-1990).

Norman F. Ramsey is the Higgins Professor ofPhysics at Harvard University. He has been a Harvard faculty member since 1947. Norman Ramsey received his A.B. and M.A. from Columbia University and degrees from Cambridge University. In1940 he received aPh.D. from Columbia University for molecular beam studies of rotational magnetic moments of molecules. He was awarded an Sc.D. by Cambridge University in1954 and by Oxford University in1973, as well as honorary D.Sc.'s from Case-Western Reserve University, Middlebury College, and Rockefeller University. After periods at the Carnegie Institution of Washington, …

Frontiers Of Material Research, Mildred S. Dresselhaus

DSLS 1989-1990

(This information was taken from the Distinguished Scientist Lecture Series Program 1989-1990).

Dr. Dresselhaus is currently Institute Professor at the Massachusetts Institute of Technology. She was formerly the holder of the Abby Rockefeller Mauze Chair in Electrical Engineering and in Physics at MIT. She is also affiliated with the Center for materials and Engineering, and with the Francis Bitter National Magnet Laboratory at MIT where some of the experimental work of her group is carried out. Dr. Dresselhaus holds professorships in MIT's Department of Electrical Engineering and Computer Science and the Department of Physics.

Dr. Dresselhaus was born in Brooklyn …