Digital Commons Network^™

Light Curve Changes In The Eclipsing Binary V719 Her, Edward G. Schmidt

Department of Physics and Astronomy: Faculty Publications

The General Catalogue of Variable Stars (Kholopov 1985) lists V719 Her as a probable type c RR Lyrae star with a period of 0.336 days. In the remarks, it is noted that another possibility is that V719 Her is a W UMa eclipsing binary with a period of .67 days. Schmidt (1991; 1993) obtained 15 light curve points in 1989-91 and concluded that V719 Her is indeed a W UMa star but with a period of .400995 days. Goderya, Leung and Schmidt (1996; 1997) subsequently obtained extensive photometry in 1993 which pro¬vided timings for five minima over an interval of …

Erratum: Equilibrium Polymerization Of Chains And Rings: A Bicritical Phenomenon, Rolfe G. Petschek

Faculty Scholarship

[No abstract available]

Measurement Of The Total Cross Section For E+E-→Hadrons At √S=10.52 Gev, R. Ammar, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

Using the CLEO detector at the Cornell Electron Storage Ring, we have made a measurement of R≡ σ(e⁺e^- → hadrons)/σ(e⁺e^-→μ⁺μ^-)=3.56± 0.01± 0.07 at √s= 10.52 GeV. This implies a value for the strong coupling constant of α_s(10.52 GeV) =0.20±0.01±0.06, or α_s (M_Z)=0.13±0.005±0.03.

Thermal Equilibrium Of Warm Clouds Of Charge With Small Aspect Ratio, Deborah L. Paulson, Ross L. Spencer

Faculty Publications

Global thermal equilibrium computations are presented for non-neutral plasmas whose radial size is much larger than their axial thickness. Axial and radial density profiles are computed for both ideal and nonideal Penning trap fields. Simple results are obtained in the limits of both low and high central density. Comparison is made to the grid calculations of Mason et al. [Phys. Plasmas 3 (5), 1502 (1996)].

Electron-Irradiation-Induced Deep Level In N-Type Gan, Z-Q. Fang, Joseph W. Hemsky, David C. Look, M. P. Mack

Physics Faculty Publications

Deep-level transient spectroscopy measurements of n-type GaN epitaxial layers irradiated with 1-MeV electrons reveal an irradiation-induced electron trap at E_C−0.18 eV. The production rate is approximately 0.2 cm⁻¹, lower than the rate of 1 cm⁻¹ found for the N vacancy by Hall-effect studies. The defect trap cannot be firmly identified at this time. ©1998 American Institute of Physics.

The Nature Of The Continuum Limit In The 2d Rp^2 Gauge Model, Simon Catterall, M. Hasenbusch, R. R. Horgan, R. Renken

Physics - All Scholarship

The RP(2) gauge model is studied in 2D. We use Monte-Carlo renormalization techniques for blocking the mean spin-spin interaction, , and the mean gauge field plaquette. The presence of the O(3) renormalized trajectory is verified and is consistent with the known three-loop beta-function. The first-order `vorticity' transition observed by Solomon et al. is confirmed, and the location of the terminating critical point is established. New scaling flows in (,) are observed associated with a large exponent kappa in the range 4~5. The scaling flows give rise to a strong cross-over effect between regions of high and low vorticity …

Fluctuation Properties Of Precipitation. Part Ii: Reconsideration Of The Meaning And Measurement Of Raindrop Size Distributions, A. R. Jameson, Alexander Kostinski

Department of Physics Publications

For M drop size categories, rain is frequently viewed simply as the superposition of M,statistically independent Poisson-distributed drop fluxes each described by its own mean concentration. Implicit in such a Poissonian model is the assumption of uncorrelated counts among the drops. However, it is well known that drop size distributions are the result of the processes of collision, coalescence, and breakup, which should lead to correlations.

This inconsistency is resolved in this work. Using 1-min disdrometer measurements, two-point cross-correlation functions are used to show that drop counts at different sizes are correlated rather than independent. Moreover, it is argued …

Optimal Renormalization Scale And Scheme For Exclusive Processes, Stanley J. Brodsky, Chueng-Ryong Ji, Alex Pang, David G. Robertson

Physics Faculty Scholarship

We use the Brodsky-Lepage-Mackenzie (BLM) method to fix the renormalization scale of the QCD coupling in exclusive hadronic amplitudes such as the pion form factor and the photon-to-pion transition form factor at large momentum transfer. Renormalization-scheme-independent commensurate scale relations are established which connect the hard scattering subprocess amplitudes that control exclusive processes to other QCD observables such as the heavy quark potential and the electron-positron annihilation cross section. The commensurate scale relation connecting the heavy quark potential, as determined from lattice gauge theory, to the photon-to-pion transition form factor is in excellent agreement with γe⃗ π0e data assuming that the …

Atomic And Electronic Structure Of Neutral And Charged Sinom Clusters, Saroj K. Nayak, B. K. Rao, S. N. Khanna, P. Jena

Physics Publications

Using molecular orbital approach and the generalized gradient approximation in the density functional theory, we have calculated the equilibrium geometries, binding energies, ionization potentials, and vertical and adiabatic electron affinities of SinOm clusters (n⩽6,m⩽12). The calculations were carried out using both Gaussian and numerical form for the atomic basis functions. Both procedures yield very similar results. The bonding in SinOm clusters is characterized by a significant charge transfer between the Si and O atoms and is stronger than in conventional semiconductor clusters. The bond distances are much less sensitive to cluster size than seen for metallic clusters. Similarly, calculated energy …

Resummation Of Ir Renormalons In A Single Meson Photoproduction, Shahin S. Agaev

Turkish Journal of Physics

Single pseudoscalar and vector mesons hard semi-inclusive photoproduction $\gamma h\rightarrow MX $ via higher twist mechanism is calculated using the QCD running coupling constant method. It is proved that in the context of this method a higher twist contribution to the photoproduction cross section cannot be normalized in terms of the meson electromagnetic form factor. The structure of infrared renormalon singularities of the higher twist subprocess cross section and the resummed expression (the Borel sum) for it are found. Comparisons are made with earlier results, as well as with leading twist cross section. Phenomenological effects of studied contributions for $\pi, …

Nature Of The Blue-Phase-Iii-Isotropic Critical Point: An Analogy With The Liquid-Gas Transition, M. A. Anisimov, V. A. Agayan, Peter J. Collings

Physics & Astronomy Faculty Works

The analogy with the liquid-gas critical point is analyzed to clarify the nature of the pretransitional behavior of physical properties in the vicinity of the Blue-Phase-m-isotropic transition in chiral liquid crystalline systems. The analogy is unusual: temperature serves as the ordering field and entropy plays the role of the order parameter. Both mean field and parametric equations of state are formulated in terms of scaling fields. The scaling fields are linear combinations of the physical fields, which are temperature and chirality. It is shown that mixing of the physical field variables naturally leads to a strong asymmetry with respect to …

Co Physisorbed On Ionic Crystals: An Extended Beg Spin-Lattice Model Of Absorbed Dipolar Molecules, T. E. Burns, John R. Dennison

All Physics Faculty Publications

The 2D dielectric phases and phase transitions of adsorbed dipolar molecules are studied using a dilute spin-one Ising model. The spin-one formulation assigns a spin S_i=±1 to a (up/down) dipole occupying a lattice site I adsorbed perpendicular to the substrate surface and S_i=0 to unoccupied sites. We relate the mean field expression for the spin-model interaction energy to a more detailed microscopic model involving dipolar, quadrupolar and repulsive interactions beyond nearest neighbor. Analytic solutions in the mean field approximation are discussed for dipole-orientation order–disorder transitions and ferroelectric-to-antiferroelectric transitions as a function of temperature and coverage. The …

Quantum Fields At Any Time, Charles G. Torre, Madhavan Varadarajan

All Physics Faculty Publications

The canonical quantum theory of a free field using arbitrary foliations of a flat two-dimensional spacetime is investigated. It is shown that dynamical evolution along arbitrary spacelike foliations is unitarily implemented on the same Fock space as that associated with inertial foliations. It follows that the Schrodinger picture exists for arbitrary foliations as a unitary image of the Heisenberg picture for the theory. An explicit construction of the Schrodinger picture image of the Heisenberg Fock space states is provided. The results presented here can be interpreted in terms of a Dirac constraint quantization of parametrized field theory. In particular, it …

Singlet Axial Current Form Factor In The Chiral Solitonic Bag Model With Massive Quarks, N. Karagöz

Turkish Journal of Physics

Singlet axial current form factor $g_A^0$ is calculated as a function of bag radius in the two flavor chiral solitonic bag model with unequal quark masses. The value of $g_A^0$ near 1 fm is sufficiently small.

The Determination Of Thermal Annealing Effect On The Dos Profile Of A-Si:H Film, Tülay Seri̇n

Turkish Journal of Physics

In this study the aim was to investigate the effect of thermal annealing on the density of states (DOS) of hydrogenated amorphous silicon (a-Si:H) by means of a Schottky structure. In order to realize that goal the sandwich structured Au/a-Si:H/a-Si:H(n$^+$-type)/Cr Schottky diode was fabricated. The junction capacitance of the samples were measured as a function of the amplitude of alternating voltage in the frequency range of 500 Hz - 100 KHz and in the annealing temperature range of 23 - 175^oC. The density of states profile as a function of both annealing temperature and energy were plotted. The effect of …

Fibonaccization And Multiparameter Q-Oscillator, M. Arik, T. Rador, G. Ünel

Turkish Journal of Physics

Starting from Coon-Baker-Yu (CBY) q-oscillator, a two parameter, multidimensional q-oscillator is formulated. It is shown that this procedure, called Fibonaccization, can be extended to any number of parameters. The relation between CBY states and Fibonacci CBY states are also investigated.

Study Of The Total Reaction Cross Section Of 17.0 Mev=N 132 Xe + 238 U Heavy Ion Interactions, J.J. Baluch, E.U. Khan, M.S. Zafar, I.E. Qureshi

Turkish Journal of Physics

We have studied heavy ion nuclear interactions of 17.0 $MeV/N$ $^{132}Xe+^{238}U$ using muscovite mica as Solid State Nuclear Track Detector (SSNTD). Experimental reaction cross section has been determined by two independent methods. Theoretical reaction cross section has been calculated by a classical formula taking into account the energy dependence of the nuclear radius parameter. The cross section determined in the present work has been compared with those at two other energies for the same reaction.

Influence Of Thermal Conductive Material On The Activation Energy Of Amorphous Silicon Thin Films, Sevilay Uğur, Merih Seri̇n

Turkish Journal of Physics

The activation energy of amorphous silicon thin films are usually measured by placing the thin film sample on a heating surface and monitoring the change in the dark conductivity as a function of temperature. The most widely used devices for temperature measurements are surface thermometers and thermocouples. Sensors such as surface thermometers or thermocouples simply measure temperature by reaching an equilibrium state with the measured environment. If the heat conduction to the sensor somehow is obscured by several reasons (sensors having a much larger dimensions than the thin film or not having proper vacuum) different thermal conduction to the sensor …

Four Ways To Tev Scale, S. Sultansoy

Turkish Journal of Physics

Four known types of colliders, which may give an opportunity to achieve TeV center of mass energies in the near future (10-15 years), are discussed. Parameters of the linac-ring type $ep$ and $\gamma p$ machines are roughly estimated. Some speculations on TeV scale physics are given. The physics goals of the TeV energy $ep$ and $\gamma p$ colliders are considered.

The Solutions Of The Classical Relativistic Two-Body Equation, Coşkun Önem

Turkish Journal of Physics

With the relativistic Kepler problem, a two-body system is studied for positronium, the hydrogen atom and $m_2 >> m_1$ cases.

Dimensionality And Energy Levels Of Quantum Mechanical Systems, Harry A. Mavromatis

Turkish Journal of Physics

The $N$-dimensional Schrödinger equation involving a general, central potential $V_N(r)$, is decomposed into a 3-dimensional component plus a term that may be treated as a dimension-dependent perturbation. This allows discussion of the general $N$-dimensional system from a 3-dimensional perspective.

Physics At Future Ep, \Gammap (Linac-Ring) And \Mup Colliders, Ilya F. Ginzburg

Turkish Journal of Physics

The physical problems for the enumerated colliders are discussed. It is taken into account that all these machines can work only after corresponding parental colliders.

Testing Deca-Tev Unified Compositeness At The 4 Tev \Mu_+\Mu_-Colliders, Vasily V. Kabachenko, Yury F. Pirogov

Turkish Journal of Physics

In the framework of the unified compositeness of leptons, quarks and Higgs bosons, the hidden local symmetry $\hat H_{loc}=SU(2)_L\times U(1)_Y$ with the heavy composite vector bosons, in addition to the SM gauge bosons, is briefly described. Supplementary hypothesis of the vector boson dominance (VBD) of the SM gauge interactions is considered. It is argued that this should produce the universal dominant residual interactions of the SM composite particles, i.e., all of the fermions and Higgs bosons. Restrictions on the universal residual fermion-fermion, fermion-boson and boson-boson interactions due to the VBD are investigated. Manifestations of the residual interactions at the 4~TeV …

Gradient Drift Instability Growth Rates From Global-Scale Modeling Of The Polar Ionosphere, Jan Josef Sojka, M. V. Subramanium, L. Zhu, Robert W. Schunk

All Physics Faculty Publications

The winter polar ionosphere, under southward interplanetary magnetic field (IMF) conditions, experiences irregularity development leading to consequences such as scintillation on transionospheric communication links. These irregularities are associated with antisunward convecting polar ionospheric patches. The gradient drift instability (GDI) has been considered a primary candidate for the generation of these irregularities, or at least the long-wavelength energy source of the irregularity-wave cascade process. The Utah State University time-dependent ionospheric model (TDIM) enables the polar cap ionosphere and its patches to be modeled on a large scale in a time-evolving manner. Hence, at each point in space and time, the TDIM …

A Compact Rotating-Mirror Autocorrelator Design For Femtosecond And Picosecond Laserpulses, D. Mark Riffe, A. J. Sabbah

All Physics Faculty Publications

An interferometric rapid-scanning autocorrelator employing two antiparallel rotating mirrors in a variable arm is optimized for maximum optical path difference as a function of the separation of the two rotating mirrors. A very compact design (mirror separation≈mirror diameter) is possible without a reduction in the maximum pulse width that can be measured.

A Lattice Model For Computing The Transmissivity Of The Cornea And Sclera, David B. Ameen, Marilyn F. Bishop, Tom Mcmullen

Physics Publications

Abstract

The method of photonic band structure is used to calculate the frequencies of light that propagate in lattice models of the cornea and sclera of the mammalian eye, providing an explanation for transparency in the cornea that first properly accounts for multiple scattering of light. Each eye tissue is modeled as an ordered array of collagen rods, and photonic band structure methods are used to solve Maxwell's equations exactly for these models, a procedure that automatically effectively includes all orders of multiple scattering. These calculations show that the dispersion relation for the cornea is linear in the visible range, …

Relativistic Electron In The Field Of Two Coulomb Centers, V.I. Matveev, D.U. Matrasulov, Kh. Yu. Rakhimov

Turkish Journal of Physics

Ground state wave function and the energy term of the relativistic electron moving in the field of two Coulomb centers are calculated analytically by the method of linear combination of atomic orbitals. Obtained analytical formula is applied to the calculation of the critical distance between two heavy nuclei at which energy term reaches the boundary of the lower continuum.

Comparison Of Metallicities Adopted For The Synthetic Ubv Photometry With Those Evaluated By Means Of Rgu Photometry, S. Karaali̇, S. Güngör, Y. Karataş

Turkish Journal of Physics

Comparison of metallicities adopted for synthetic UBV photometry with those evaluated by means of RGU photometry for 92 stars is presented. The agreement is only for zero metallicity. The discrepancy increases to low metallicities which cover Intermediate Population II and Population II main-sequence stars. U-G and G-R colour indices are transformed from UBV synthetic data and do not include any observational error. Therefore, the disagreement may originate from a systematic error in the metallicity calibration of relatively metal-poor stars in RGU photometry. Keywords: photometry - stars : abundances - metal-poor.

The Structure Of Liquid Alloys With Chemical Short Range Order, Serap Dalgiç, Seyfettin Dalgiç, Mehmet Tomak

Turkish Journal of Physics

We present a study of the structural properties of liquid binary alloys with chemical short range order starting from the effective interatomic pair potentials. The interatomic pair potentials are derived using the second order pseudopotential theory and the static structure is obtained using the modified hypernetted chain approximation. The partial structure factors $S_{ij}(q)$ and the concentration - fluctuation structure factor $S_{cc}(q)$ are calculated to analize the ordering tendencies in a binary alloy. In this work, liquid Li-Mg alloy is studied as a test case. The agreement between theory and experiment is quite good. We conclude that the structural properties of …

Crystal Data For A_3b_5c_9-Type Ternary Compounds, Hüsnü Özkan, Nizami Gasanly, İbrahim Yilmaz, Ali Çulfaz, Vyaceslav Nagiev

Turkish Journal of Physics

X-ray powder diffraction data were obtained for Cu$_3$Ga$_5$Se$_9$, Cu$_3$In$_5$Se$_9$, Cu$_3$In$_5$Te$_9$, Ag$_3$In$_5$S$_9$, Ag$_3$Ga$_5$S$_9$, Ag$_3$In$_5$Se$_9$, and Ag$_3$Ga$_5$Te$_9$ ternary compounds. The data indicate that these compounds crystallize in orthorhombic, monoclinic, orthorhombic, monoclinic, tetragonal, tetragonal, and orthorhombic systems, respectively.