UScholar Works
 
Filters: Department: "Physics" Collection: "ir_uspace"
626 - 650 of 924
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CreatorTitleDescriptionSubjectDate
626 Gondolo, PaoloPrompt atmospheric neutrinos and muons: NLO vs LO QCD predictionsWe compare the leading and next-to-leading order QCD predictions for the flux of atmospheric muons and neutrinos from decays of charmed particles. We find that the full NLO lepton fluxes can be approximated to within ~10% by the Born-level fluxes multiplied by an overall factor of 2.2-2.4, which d...Atmospheric flux; Prompt flux; Charm2000-01
627 Saam, BrianProtection circuitry for high-power diode laser arraysA comprehensive protection scheme is presented for use with high-power (;500 W dc input! diode laser arrays. The circuitry requires no separate power, using instead the voltage from the laser's power supply. Overcurrent and overvoltage silicon controlled rectifier crowbars are the primary protection...Protection circuitry; High-power diode laser arrays1998
628 Ailion, David CharlesProtein hydration changes in the formation of the nicotinamide adenine dinucleotide complexes of glyceraldehyde 3-phosphate dehydrogenase of yeast. II. The spin lattice relaxation of solvent water protonsThe glyceraldehyde 3-phosphate dehydrogenase of yeast is known to undergo a particle volume contraction and the commensurate loss of a hydration component when it forms a complex with NAD. We have inquired whether the water movement in the conformational transition can be monitored by measurements ...Protein hydration; Nicotinamide adenine dinucleotide complexes; Glyceraldehyde 3 phosphate dehydrogenase; Solvent water protons1973
629 DeTar, CarletonPseudodeconfinement and dynamical confinement in the quark plasmaWe elaborate upon phenomenological models of high-temperature hadronic matter at zero baryon density. We discuss the choice of a practical set of "fundamental" degrees of freedom, indicate their relationship to dynamically confined plasma modes, and suggest in what way they may account for the phase...Quark plasma; Gluon plasma; Hadronic matter; Deconfinement; Glueballs; Mesons; Phase transitions1988-04
630 Mishchenko, EugenePseudospin ferromagnetism in double-quantum-wire systemsWe propose that a pseudospin ferromagnetic (i.e., interwire coherent) state can exist in a system of two parallel wires of finite width in the presence of a perpendicular magnetic field. This novel quantum many-body state appears when the interwire distance decreases below a certain critical value ...Coulomb drag; Quantum wires2005-08
631 Boehme, Christoph; Friedrich, FrancesPulsed EDMR study of charge trapping at Pb centersLow temperature pulsed electrically detected magnetic resonance (pEDMR) measurements of charge trapping and recombination transitions involving Pb centers at the c-Si (111) /Si02 interface are presented. The results of these experiments show that when a conduction electron is trapped, it forms a str...Charge trapping; Lande factor2005
632 DeTar, CarletonQCD equation of state with 2+1 flavors of improved staggered quarksWe report results for the interaction measure, pressure, and energy density for nonzero-temperature QCD with 2 + 1 flavors of improved staggered quarks. In our simulations, we use a Symanzik improved gauge action and the Asqtad O(a2) improved staggered quark action for lattices with temporal extent ...Staggered quarks; Quark-gluon plasma2007-05
633 DeTar, CarletonQCD spectrum with three quark flavorsWe present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks - two light and one strange-and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge action and an improved Kogut-Susskind quark action. The lat...Dynamical quarks2001-08
634 DeTar, CarletonQCD thermodynamics with 2+1 flavors at nonzero chemical potentialWe present results for the QCD equation of state, quark densities, and susceptibilities at nonzero chemical potential, using 2 + 1 flavor asqtad ensembles with Nt = 4. The ensembles lie on a trajectory of constant physics for which mud ≈ 0:1ms. The calculation is performed using the Taylor expansi...Taylor expansion2008-01
635 DeTar, CarletonQCD thermodynamics with an improved lattice actionWe have investigated QCD with two flavors of degenerate fermions using the Symanzik-improvement program for both the gauge and fermion actions. Our study focuses on the deconfinement transition on an Nt=4 lattice. Having located the thermal transition, we performed zero temperature simulations nea...Wilson fermions; Polyakov loop; Chiral symmetry; Phase transitions1997-11
636 DeTar, CarletonQCD thermodynamics with three flavors of improved staggered quarksWe report on a study of QCD thermodynamics with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad O(a2) improved staggered quark action. Simulations were carried out with lattice spacings 1/4T, 1/6T, and 1/8T both for three degenerate quarks with masses less than or equa...Quark-gluon plasma; Staggered quarks; Phase transitions; Polyakov loop2005-02
637 DeTar, CarletonQCD thermodynamics with two flavors at Nt=6The first results of numerical simulations of quantum chromodynamics on the Intel iPSC/860 parallel processor are presented. We performed calculations with two flavors of Kogut-Susskind quarks at Nt = 6 with masses of 0.15T and 0.075T (0.025 and 0.0125 in lattice units) in order to locate the crosso...Kogut-Susskind quarks; Crossover temperature; Chiral symmetry; Polyakov loop; Phase transitions1992-05
638 DeTar, CarletonQCD thermodynamics with two flavors of Wilson quarks at Nt=6We report on a study of hadron thermodynamics with two flavors of Wilson quarks on 123 X6 lattices. We have studied the crossover between the high- and low-temperature regimes for three values of the hopping parameter, K=0. 16, 0.17, and 0.18. At each of these values of K we have carried out spect...Wilson quarks; Staggered quarks; Chiral symmetry; Phase transitions1992-11
639 DeTar, CarletonQCD thermodynamics with Wilson quarks at large KWe extend our study of the high temperature transition with two flavors of Wilson quarks on 123 x 6 lattices to K = 0.19. We also perform spectrum calculations on 123 x 24 lattices at K = 0.19 to find the physical lattice spacing and quark mass. At this value of K the transition is remarkable in tha...Wilson quarks; Polyakov loop; Phase transitions1994-09
640 Ailion, David Charles; Morris, Alan H.Quantitative assessment of pulmonary edema by nuclear magnetic resonance methodsConsiderable progress has been made in the application of nuclear magnetic resonance (NMR) imaging and nonimaging techniques to the quantitative assessment of pulmonary edema. NMR measurements offer the advantages of being noninvasive, relatively rapid, and easily repeatable. In addition, NMR imagin...Quantitative assessment1988
641 Williams, Clayton C.; Huang, YufengQuantitative two-dimensional dopant profile measurement and inverse modeling by scanning capacitance microscopyQuantitative dopant profile measurements are performed on a nanometer scale by scanning capacitance microscopy (SCM). An atomic force microscope is used to position a nanometer scale tip at a semiconductor surface, and local capacitance change is measured as a function of sample bias. A new feedback...Dopant profile; Capacitance change; Scanning capacitance microscopy; Feedback control1995
642 Wu, Yong-ShiQuantized Hall conductance as a topological invariantWhenever the Fermi level lies in a gap (or mobility gap) the bulk Hall conductance can be expressed in a topologically invariant form showing the quantization explicitly. The new formulation generalizes the earlier result by Thouless, Kohmoto, Nightingale, and den Nijs to the situation where many-bo...Hall conductance; Fermi gap; Degeneracy1985-03
643 Wu, Yong-ShiQuantized spin Hall effect in 3He-A and other p-wave paired Fermi systemsIn this paper, we propose the quantized spin Hall effect (SHE) in the vortex state of a rotating p-wave paired Fermi system in an inhomogeneous magnetic field and in a weak periodic potential. It is the three-dimensional extension of the spin Hall effect for a 3He-A superfluid film previously stud...Fermi systems; Spin Hall conductance2008-04
644 Wu, Yong-ShiQuantum dynamics and statistics of vortices in two-dimensional superfluidsThe phase change of the wave function of a superfluid film as a vortex moves around a closed path counts the number of superfluid particles enclosed by that path. This result is used to investigate whether such vortices obey "fractional statistics." We conclude that this is not the case in compress...Superfluid films; Vortices; Fractional statistics1985-12
645 Wu, Yong-ShiQuantum group, Bethe ansatz equations, and Bloch wave functions in magnetic fieldsThe wave functions for a two-dimensional Bloch electron in uniform magnetic fields at the mid-band points are studied by exploiting a connection to the quantum group Uq(sl2): A linear combination of its generators gives the Hamiltonian. We apply both analytic and numerical methods to obtain and an...Bloch electron1996-04
646 Wu, Yong-ShiQuantum phase transition and engineering in two-component BEC in optical latticesIn this paper we review recent progress in studying quantum phase transitions in one- and two-component Bose-Einstein condensates (BEC) in optical lattices. These phase transitions involve the emergence and disappearance of quantum coherence over whole optical lattice and of linear superposition of...2003
647 Wu, Yong-ShiQuantum phase transition in a multicomponent Bose-Einstein condensate in optical latticesWe present a general lattice model for a multicomponent atomic Bose-Einstein system in an optical lattice. Using the model, we analytically study the quantum phase transition between the Mott insulator and a superfluid. A mean-field theory is developed from the Mott-insulator ground state. When the...Quantum phase transitions; Optical lattices; Bose-Einstein condensation; Boson-Hubbard model; Superfluids2003-01
648 DeTar, CarletonQuark loop effects in semileptonic form factors for heavy-light mesonsWe present preliminary results of a determination of the semileptonic form factor for the decay of pseudoscalar heavy-light mesons to pseudoscalar light-light mesons in full QCD. In this preliminary study we focus on the effects of dynamical quark loops. Accordingly, we compare results of simulati...Semileptonic decay; Form factors; Quark loops; Wilson quarks2004-03
649 DeTar, CarletonQuark-bag model with low-energy pion interactions. I. TheoryA standard method for restoring chiral symmetry in the bag model is to introduce an explicit external pion field. Questions of the consistency and compatibility of this method with the assumptions of the static-cavity approximation of the bag model are discussed. An approximate version of the mode...Bag models; Quark bag; Chiral symmetry; Pion bag; Pion field1981-08
650 DeTar, CarletonQuark-bag model with low-energy pion interactions. II. ApplicationThe hybrid pion-quark-bag model discussed in I is applied to a calculation of masses, pion couplings, and other parameters of various light hadrons in an effort to determine the extent to which the bag parameters must be modified in the presence of pion interactions. Corrections for the finite spr...Bag models; Quark bag; Chiral symmetry; Pion field; Nucleons1981-08
626 - 650 of 924