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Full-Text Articles in Physics

The Neutralino Sector In Strongly Interacting Supersymmetric Models, Tonnis Ter Veldhuis Dec 1994

The Neutralino Sector In Strongly Interacting Supersymmetric Models, Tonnis Ter Veldhuis

Tonnis ter Veldhuis

No abstract provided.


A Comparison Of Higgs Mass Bounds In The Sm And The Mssm, Tonnis Ter Veldhuis, T Weiler, M Diaz Nov 1994

A Comparison Of Higgs Mass Bounds In The Sm And The Mssm, Tonnis Ter Veldhuis, T Weiler, M Diaz

Tonnis ter Veldhuis

No abstract provided.


The Spectral Center Of Gravity Effect And Auditory Filter Bandwidth, Marc Fagelson, Linda M. Thibodeau Nov 1994

The Spectral Center Of Gravity Effect And Auditory Filter Bandwidth, Marc Fagelson, Linda M. Thibodeau

Marc A. Fagelson

The spectral center of gravity refers to a listener’s averaging of frequency and intensity components when formant peaks in a speechlike signal are separated by 3.5 Bark units or less. In this paper a total of 18 synthetic vowels whose spectra approximated /ae/ or /inverted vee/ were generated digitally; each stimulus contained the first 40 harmonics of a 100‐Hz fundamental. Nine spectra contained three formants, while the balance contained only two. Subjects with normal hearing and mild high‐frequency hearing loss above 3000 Hz were instructed to identify synthetic vowels as either /ae/ or /inverted vee/ as ...


Measurements Of The Electric And Magnetic Form Factors Of The Proton From Q2=1.75 To 8.83 (Gev/C)2, L Andivahis, R S. Hicks, R A. Miskimen, Gerald Alvin Peterson, S Rokni Oct 1994

Measurements Of The Electric And Magnetic Form Factors Of The Proton From Q2=1.75 To 8.83 (Gev/C)2, L Andivahis, R S. Hicks, R A. Miskimen, Gerald Alvin Peterson, S Rokni

Gerald Alvin Peterson

The proton elastic form factors GEp(Q2) and GMp(Q2) have been extracted for Q2=1.75 to 8.83 (GeV/c)2 via a Rosenbluth separation to ep elastic cross section measurements in the angular range 13°≤θ≤90°. The Q2 range covered more than doubles that of the existing data. For Q2<4 >(GeV/c)2, where the data overlap with previous measurements, the total uncertainties have been reduced to < 14% in GEp and < 1.5% in GMp. Results for GEp(Q2) are consistent with the dipole fit GD(Q2)=(1+Q2/0.71)-2, while those for GMp(Q2)/μpGD(Q2) decrease smoothly from 1.05 to 0.92. Deviations from form factor scaling are observed up to 20%. The ratio Q2F2/F1 is observed to approach a constant value for Q2>3 (GeV/c)2. Comparisons are made to vector meson dominance, dimensional scaling, QCD sum rule, diquark, and constituent quark models, none of which fully characterize all the new ...


Measurements Of The (E,E’Pπ-) Reaction On Nuclei In The Nucleon Resonance Region, L Elouadrhiri, R A. Miskimen, J Button-Shafer, P Degtyarenko,, Gerald Alvin Peterson, S Shuvalov, K Wang Oct 1994

Measurements Of The (E,E’Pπ-) Reaction On Nuclei In The Nucleon Resonance Region, L Elouadrhiri, R A. Miskimen, J Button-Shafer, P Degtyarenko,, Gerald Alvin Peterson, S Shuvalov, K Wang

Gerald Alvin Peterson

Nucleon resonances beyond the Δ(1232) have been observed in complex nuclei. Measurements of the (e,e’pπ-) reaction, at an incident energy of 14.5 GeV with 1.1 GeV


Strongly Interacting Longitudinal Gauge Bosons In Supersymmetric Models, T Clark, Tonnis Ter Veldhuis Sep 1994

Strongly Interacting Longitudinal Gauge Bosons In Supersymmetric Models, T Clark, Tonnis Ter Veldhuis

Tonnis ter Veldhuis

No abstract provided.


X-Ray Studies Of Bond-Orientational Order In Liquid-Crystalline Orthogonal Hexatic-B Phase, E. Gorecka, Li Chen, Oleg Lavrentovich, W. Pyzuk Aug 1994

X-Ray Studies Of Bond-Orientational Order In Liquid-Crystalline Orthogonal Hexatic-B Phase, E. Gorecka, Li Chen, Oleg Lavrentovich, W. Pyzuk

Oleg Lavrentovich

X-ray scattering measurements have been carried out for free-standing, thick . monodomain films of the orthogonal hexatic-B phase. From Fourier analysis of X-scans, 6n-fold-symmetry order parameters were determined and proved to fulfill the scaling relation C6n = C6n+lambdan(n-1). The temperature behavior of C6 and lambda was found nonuniversal when comparing homologues, PIR5 and PIR7, differing in their range of the hexatic phase. The hexatic order parameter varies with the critical exponents 0.25, 0.20 (+/- 0.03), respectively. For comparison results for compound RFL6, of other homologue series, are presented.


Radiative Corrections To Charged Higgs Production In E+ E- Colliders, M Diaz, Tonnis Ter Veldhuis Jul 1994

Radiative Corrections To Charged Higgs Production In E+ E- Colliders, M Diaz, Tonnis Ter Veldhuis

Tonnis ter Veldhuis

No abstract provided.


Multiple Hadron Production By 14.5 Gev Electron And Positron Scattering From Nuclear Targets, P V. Degtyarenko, J Button-Shafer, L Elouadrhiri, R A. Miskimen, Gerald Alvin Peterson, K Wang Jul 1994

Multiple Hadron Production By 14.5 Gev Electron And Positron Scattering From Nuclear Targets, P V. Degtyarenko, J Button-Shafer, L Elouadrhiri, R A. Miskimen, Gerald Alvin Peterson, K Wang

Gerald Alvin Peterson

Multiple proton and pion electroproduction from nuclei are studied. Final states including at least two protons produced by the interaction of 14.5 GeV electrons and positrons with light nuclei (mainly 12C and 16O) have been measured, and compared with analogous data from 40Ar. Scattered electrons and positrons were detected in the energy transfer range from 0.2 to 12.5 GeV, and four-momentum transfer squared range from 0.1 to 5.0 GeV2/c2. Phenomenological characteristics of the secondary hadron production cross sections such as temperature and velocity of the effective source of hadrons were found to be dependent ...


First-Principles All-Electron Theory Of Atomic Short-Range Ordering In Metallic Alloys: D022- Versus L12-Like Correlations, Duane D. Johnson, J. B. Staunton, F. J. Pinski Jul 1994

First-Principles All-Electron Theory Of Atomic Short-Range Ordering In Metallic Alloys: D022- Versus L12-Like Correlations, Duane D. Johnson, J. B. Staunton, F. J. Pinski

Duane D. Johnson

We use a ‘‘first-principles’’ concentration-wave approach based on a finite-temperature, electronic density-functional, mean-field, grand potential of the random alloy to investigate the high-temperature atomic short-range order (ASRO) in Ni75V25 and Pd75V25 solid solutions. Experimentally, these similar alloys both develop D022-type long-range order at low temperatures but different ASRO at high temperatures. Our calculations describe the measured ASRO well. We compare these results with those found for a hypothetical Co75Ti25 solid solution. Since this alloy orders directly from the melt into the L12 phase, it should exhibit strong L12-like ASRO, as we find in our calculations. We analyze the features in ...


Mass Bounds In The Standard Model, T Clark, B Haeri, S Love, M Walker, Tonnis Ter Veldhuis Jun 1994

Mass Bounds In The Standard Model, T Clark, B Haeri, S Love, M Walker, Tonnis Ter Veldhuis

Tonnis ter Veldhuis

No abstract provided.


Surface-Induced Ordering In Asymmetric Block Copolymers, Y. Liu, W. Zhao, X. Zheng, Alexander H. King, A. Sing, M. H. Rafailovich, J. Sokolov, K. H. Dai, E. J. Kramer, S. A. Schwarz, O. Gebizlioglu, S. K. Sinha Jun 1994

Surface-Induced Ordering In Asymmetric Block Copolymers, Y. Liu, W. Zhao, X. Zheng, Alexander H. King, A. Sing, M. H. Rafailovich, J. Sokolov, K. H. Dai, E. J. Kramer, S. A. Schwarz, O. Gebizlioglu, S. K. Sinha

Alexander H. King

The surface-induced ordering in thin films of asymmetric deuterated polystyrene (dPS)- poly(viny1pyridine) (PVP) diblock and triblock copolymers of comparable polymerization index and PVP volume fraction - 0.25) was studied using transmission electron microscopy, atomic force microscopy, secondary ion massspectrometry, and neutron reflectivity. The morphology of both di- and triblock copolymer films was found to be cylindrical except for the layer adjacent to the silicon oxide surface, which due to the strong interaction of silica with PVP, was lamellar. The spacing between adjacent cylindrical layers was found to be consistent with mean field theory predictions. In the triblock copolymer films ...


Why Magnification Works, Terry L. Smith, Jay S. Huebner Jan 1994

Why Magnification Works, Terry L. Smith, Jay S. Huebner

Jay S Huebner

The simplest way to magnify the view of a small object is to bring the object closer to the eye, and of course science teachers know about magnifying glasses, telescopes, and microscopes.But why magnification works seems intuitive and is not usually explained to our students. We present here a few ideas on magnification that we use in our classroom and some general information on vision that we hope will be helpful to other teachers.


Biaxiality In A Cyclic Thermotropic Nematic Liquid-Crystal, Jian-Feng Li, V. Percec, Ch. Rosenblatt, Oleg Lavrentovich Jan 1994

Biaxiality In A Cyclic Thermotropic Nematic Liquid-Crystal, Jian-Feng Li, V. Percec, Ch. Rosenblatt, Oleg Lavrentovich

Oleg Lavrentovich

Birefringence and textural data are presented for a ring-shaped trimeric liquid crystal. The material apparently undergoes a uniaxial-to-biaxial nematic phase transition as a function of temperature.


Click‐Evoked Otoacoustic Emissions In Normal‐Hearing Children, Jacek Smurzynski Jan 1994

Click‐Evoked Otoacoustic Emissions In Normal‐Hearing Children, Jacek Smurzynski

Jacek Smurzynski

Click‐evoked otoacoustic emissions (CEOEs) were collected from 167 ears of 106 normal‐hearing children using the ILO88 system with the stimuli presented at 80±2 dB pe SPL. Subjects were divided into five age groups: 13–24 months (24 ears), 25–36 months (49 ears), 37–48 months (31 ears), 49–60 months (34 ears), and 61–72 months (29 ears). All subjects had normal middle ear function and their audiological data were within normal limits. Mean overall CEOE level was calculated for each age group. None was statistically different from any other. However, the data of the 167 ...


Thermodynamics Of A Free Q Fermion Gas, Asim Gangopadhyaya Dec 1993

Thermodynamics Of A Free Q Fermion Gas, Asim Gangopadhyaya

Asim Gangopadhyaya

We study the thermodynamics of a q-fermion gas for complex values of q on the unit circle. Special emphasis is given to the study of the virial coefficients and the specific heat of this gas. In particular, it is shown that if any state can accommodate up to p q-fermions, then the first p virial coefficients of such a gas are the same as that of a gas of free bosons. Explicit expressions for the deviation of higher virial coefficients from the corresponding values for a Bose gas are obtained. Further, as for ordinary fermions, it is shown that the ...


Hydrogen Release Kinetics During Reactive Magnetron Sputter Deposition Of A‐Si:H: An Isotope Labeling Study, J. Abelson, L. Mandrell, James Doyle Dec 1993

Hydrogen Release Kinetics During Reactive Magnetron Sputter Deposition Of A‐Si:H: An Isotope Labeling Study, J. Abelson, L. Mandrell, James Doyle

James R. Doyle

No abstract provided.


Effect Of Anode Bias On Plasma Confinement In Dc Magnetron Discharges, James Doyle, A. Nurrudin, J. Abelson Dec 1993

Effect Of Anode Bias On Plasma Confinement In Dc Magnetron Discharges, James Doyle, A. Nurrudin, J. Abelson

James R. Doyle

No abstract provided.


Hexagons And Squares In A Passive Nonlinear Optical System, John Geddes, R.A. Indik, J.V. Moloney, Willie Firth Dec 1993

Hexagons And Squares In A Passive Nonlinear Optical System, John Geddes, R.A. Indik, J.V. Moloney, Willie Firth

John B. Geddes

Pattern formation is analyzed and simulated in a nonlinear optical system involving all three space dimensions as well as time in an essential way. This system, counterpropagation in a Kerr medium, is shown to lose stability, for sufficient pump intensity, to a nonuniform spatial pattern. We observe hexagonal patterns in a self-focusing medium, and squares in a self-defocusing one, in good agreement with analysis based on symmetry and asymptotic expansions.


Macro-Trench Studies Of The Surface Reaction Probability In A-Si:H Deposition, A. Nurrudin, James Doyle, J.R. Abelson Dec 1993

Macro-Trench Studies Of The Surface Reaction Probability In A-Si:H Deposition, A. Nurrudin, James Doyle, J.R. Abelson

James R. Doyle

No abstract provided.


Direct Simulation Monte Carlo For Thin Film Bearings, Alejandro Garcia, B. Alder, F. J. Alexander Dec 1993

Direct Simulation Monte Carlo For Thin Film Bearings, Alejandro Garcia, B. Alder, F. J. Alexander

Alejandro Garcia

The direct simulation Monte Carlo (DSMC) scheme is used to study the gas flow under a read/write head positioned nanometers above a moving disk drive platter (the slider bearing problem). In most cases, impressive agreement is found between the particle-based simulation and numerical solutions of the continuum hydrodynamic Reynolds equation which has been corrected for slip. However, at very high platter speeds the gas is far from equilibrium, and the load capacity for the slider bearing cannot be accurately computed from the hydrodynamic pressure.


Chiral Sum Rules And Their Phenomenology, John Donoghue, Eugene Golwich Dec 1993

Chiral Sum Rules And Their Phenomenology, John Donoghue, Eugene Golwich

John Donoghue

We present an analysis of four sum rules, each based on chiral symmetry and containing the difference p&(s)—p&(s) of isovector vector and axial-vector spectral functions. Experimental data from ~ lepton decay and electron-positron scattering identify the spectral functions over a limited kinematic domain. We summarize the status of the existing database. However, a successful determination of the sum rules requires additional content, in the form of theoretical input. We show how chiral symmetry and the operator product expansion can be used to constrain the spectral functions, respectively, in the low energy and the high energy limits and proceed ...


General Relativity As An Effective Field Theory: The Leading Quantum Corrections, John Donoghue Dec 1993

General Relativity As An Effective Field Theory: The Leading Quantum Corrections, John Donoghue

John Donoghue

I describe the treatment of gravity as a quantum effective field theory. This allows a natural separation of the (known) low energy quantum effects from the (unknown) high energy contributions. Within this framework, gravity is a well behaved quantum field theory at ordinary energies. In studying the class of quantum corrections at low energy, the dominant effects at large distance can be isolated, as these are due to the propagaion of the massless particles (including gravitons) of the theory and are manifested in the nonlocal/nonanalytic contributions to vertex functions and propagators. These leading quantum corrections are parameter-free and represent ...


Determination Of Plasma Parameters In A Dc Arcjet Diamond Reactor: Part 1, Scott Reeve, Wayne Weimer Dec 1993

Determination Of Plasma Parameters In A Dc Arcjet Diamond Reactor: Part 1, Scott Reeve, Wayne Weimer

Scott Reeve

No abstract provided.


Microscopic Simulation Of Dilute Gases With Adjustable Transport Coefficients, Alejandro Garcia, F. Baras, M. Malek Mansour Dec 1993

Microscopic Simulation Of Dilute Gases With Adjustable Transport Coefficients, Alejandro Garcia, F. Baras, M. Malek Mansour

Alejandro Garcia

The Bird algorithm is a computationally efficient method for simulating dilute gas flows. However, due to the relatively large transport coefficients at low densities, high Rayleigh or Reynolds numbers are difficult to achieve by this technique. We present a modified version of the Bird algorithm in which the relaxation processes are enhanced and the transport coefficients reduced, while preserving the correct equilibrium and nonequilibrium fluid properties. The present algorithm is found to be two to three orders of magnitude faster than molecular dynamics for simulating complex hydrodynamical flows.