Search results for "Length"

showing 10 items of 2188 documents

On the radio emitting high mass X-ray binary LS 5039

2001

We present new optical - near-IR spectroscopic and photometric observations of the newly discovered galactic microquasar LS 5039, which indicate a classification for the mass donor in the system of O6.5V((f)). Optical spectroscopy and photometry shows no variability over a timescale of years, and we find no evidence of modulation by, or emission from the compact companion in these data. However significant photometric variability (~0.4 mag) is present in the H and K bands between 1995-2000. Such variability has been observed in other radio bright X-ray binaries where it has been attributed to synchrotron emission from the jet. However, given the non-thermal spectral index of the radio emiss…

PhysicsSpectral indexAstrophysics::High Energy Astrophysical PhenomenaX-ray binaryAstronomyAstronomy and AstrophysicsAstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsPhotometry (optics)WavelengthOrders of magnitude (time)Space and Planetary ScienceModulationMagnitude (astronomy)Astrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary AstrophysicsSpectroscopyAstrophysics::Galaxy Astrophysics
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Precise measurement of the dynamical masses in AB Doradus

2007

AbstractThe radio stars ABDor A and ABDor B (=Rst137B) are the main components of the ABDoradus system. Both stars are double (ABDor A/ABDor C and ABDor Ba/ABDor Bb) and usual targets of astrometric instruments at optical (Hipparcos), infrared (VLT), and radio (VLBI) wavelengths. From a combination of all astrometric data available, we have obtained precise limits to the dynamical mass of both binaries in AB Doradus. The determination of the mass of ABDor C (0.090±0.003 M⊙) is important, since this object constitutes one of the few calibration points used to test theoretical evolutionary models of low-mass young stars. Follow-up observations both in radio (VLBI) and optical wavelengths (VLT…

PhysicsStarsWavelengthSpace and Planetary ScienceInfraredVery-long-baseline interferometryCalibrationAstronomyAstronomy and AstrophysicsAstrophysicsAstrometryProceedings of the International Astronomical Union
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Nonlocality in superconducting microstructures

2001

We discuss experimental evidence of nonlocality in electron transport of small structures. It is shown that for superconductors reasonable agreement with experiment can be achieved by assuming exponential decay of the nonlocal interaction ∝ exp(—Lξ), where L is the distance between the interacting points and ξ is the correlation length. ξ is associated with the Ginzburg - Landau coherence length ξGL.

PhysicsSuperconductivityQuantum nonlocalityCondensed matter physicsQuantum mechanicsExponential decayMicrostructureCoherence lengthPhysical Review B
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Surface effects on spinodal decomposition in binary mixtures: The case with long-ranged surface fields

1997

We present detailed numerical results for phase-separation kinetics of critical binary mixtures in the vicinity of a surface that exerts a long-ranged attractive force on one of the components of the mixture. We consider surface potentials of the form $V(Z)\ensuremath{\sim}{Z}^{\ensuremath{-}n}$, where $Z$ is the distance from the surface and $n=1,2,3$. In particular, we investigate the interplay of the surface wetting layer with the dynamics of domain growth. We find that the wetting layer at the surface exhibits power-law growth with an exponent that depends on $n$, in contrast to the case with a short-ranged surface potential, where the growth is presumably logarithmic. From correlation …

PhysicsSurface (mathematics)Characteristic lengthLogarithmCondensed matter physicsSpinodal decompositionPerpendicularExponentBinary numberThermodynamicsWetting layerPhysical Review E
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Improved measurement of theB 0 andB + meson lifetimes

1996

The lifetimes of the B 0 and B + mesons have been measured with the Aleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991 1994. In the first of three methods, semileptonic decays of B 0 and B + mesons were partially reconstructed by identifying events containing a lepton with an associated D*- orbar D^0 meson. The second method used fully reconstructed B 0 and B + mesons. The third method, used to measure the B 0 lifetime, employed a partial reconstruction technique to identify B 0→ D*- π + X decays. The combined results are begin{gathered} tau _0 = 1.55 ± 0.06 ± 0.03 ps, \ tau _ + = 1.58 ± 0.09 ± 0.03 ps, \ tfrac{{tau _ + }}{{tau _0 }} = 1.03 ±…

PhysicsSystematic errorParticle physicsTime projection chamberPhysics and Astronomy (miscellaneous)MesonNuclear TheoryHigh Energy Physics::PhenomenologyHadronMeasure (mathematics)ALEPH ExperimentNuclear physicsDecay lengthHigh Energy Physics::ExperimentNuclear ExperimentALEPH experimentLepton
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A Wavelength-shifting Optical Module (WOM) for in-ice neutrino detectors

2016

7th Very Large Volume Neutrino Telescope Workshop, Rome, Italy, 14 Sep 2015 - 16 Sep 2015 ; The European physical journal / Web of Conferences 116, 01006 (2016). doi:10.1051/epjconf/201611601006

PhysicsTotal internal reflection010504 meteorology & atmospheric sciences010308 nuclear & particles physicsbusiness.industryPhysics::Instrumentation and DetectorsPhysicsQC1-999Astrophysics::High Energy Astrophysical PhenomenaDetectorWavelength shifter01 natural sciencesNoise (electronics)530WavelengthOpticsNeutrino detector0103 physical sciencesddc:530businessCherenkov radiation0105 earth and related environmental sciencesDark current
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Hyperfine structure of the 3d34s4p6G multiplet of atomic vanadium

2011

The spectrum of atomic vanadium was recorded using high-resolution Fourier transform spectroscopy with optical bandpass filters in the wavelength range from 360 to 500 nm. Vanadium atoms are produced and excited in a hollow-cathode discharge. The main focus lies on the determination of the magnetic dipole hyperfine constants A of the lowest multiplet of odd parity, the 6G of the configuration 3d34s4p, the hyperfine structure (HFS) of which was unknown to date. The HFS of the lines, connecting this multiplet with the multiplets 3d34s5s 6F, 3d34s4d 6H and 3d34s4d 6G, was observed and analysed. New results are presented for all six levels belonging to 3d34s4p 6G as well as for seven high-lying…

PhysicsWavelength rangeVanadiumchemistry.chemical_elementCondensed Matter PhysicsAtomic and Molecular Physics and OpticsFourier transform spectroscopyFormalism (philosophy of mathematics)chemistryExcited statePhysics::Atomic PhysicsAtomic physicsHyperfine structureMultipletMagnetic dipoleJournal of Physics B: Atomic, Molecular and Optical Physics
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CONDENSATE FRACTION IN THE DYNAMIC STRUCTURE FUNCTION OF BOSE FLUIDS

2007

We present results on the behavior of the dynamic structure function in the short wave length limit using the equation of motion method. The one-body continuity equation defines the self-energy, which becomes a functional of the fluctuating two-body correlation function. We evaluate the self-energy in this limit and show that sum rules up to the second moment, which requires the self-energy in the short wave length limit and zero frequency to be proportional to the kinetic energy per particle, are exactly satisfied. We compare our results with the impulse approximation and calculate the condensate fraction. An analytic expression for the momentum distribution is also derived.

PhysicsWavelengthClassical mechanicsContinuity equationMathematical analysisStructure functionSecond moment of areaEquations of motionStatistical and Nonlinear PhysicsImpulse (physics)Condensed Matter PhysicsKinetic energySuperfluid helium-4International Journal of Modern Physics B
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A method of evaluation of measured light intensities and degrees of polarization of a unit volume of turbid air

1965

In order to interpret scattered light measurements a comparison with theoretical values is necessary. It is demonstrated by means of an example the possibility to obtain a first view on the measurement results. From calculated values of various aerosol size distribution models as well as from measurements were computed: 1) the angular quotients of scattered light intensity (i.e., quotients of intensity at two scattering angles and the same wavelength) and 2) the wavelength quotients (i.e., quotients of intensity at two wavelengths and the same scattering angle). The comparison between measured and theoretical values informs us of the exponent of the aerosol size distribution and its boundar…

PhysicsWavelengthGeophysicsOpticsGeochemistry and Petrologybusiness.industryScatteringExponentUnit volumeScattered lightbusinessPolarization (waves)AerosolPure and Applied Geophysics PAGEOPH
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Doppler free ?dark resonances? for hyperfine measurements and isotope shifts in Ca+ isotopes in a Paul trap

1995

We have observed “dark resonances” in theA-type level structure, formed by the 4S1/2 ground state, the 4P1/2 excited state and the low lying metastable 3D3/2 state in the Calcium ion, confined in a Paul radio-frequency trap. These Doppler-free and potentially very narrow resonances were used to determine the magnetic dipole hyperfine interaction constant A for the 4P1/2 and 3D3/2 state of43Ca+, giving −142(8) MHz and −48.3(1.6) MHz, respectively. From measurements of the P-D (E1) and S-D (E2) transition wavelength in a mixture of43Ca+ and40Ca+ we determined the isotope shifts of these lines.

PhysicsWavelengthIsotopeMetastabilityExcited statePhysics::Atomic PhysicsIon trapAtomic physicsGround stateHyperfine structureMagnetic dipoleAtomic and Molecular Physics and OpticsZeitschrift f�r Physik D Atoms, Molecules and Clusters
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