3,719 research outputs found

    Coulomb-hadron phase factor and spin phenomena in a wide region of transfer momenta

    Get PDF
    The Coulomb-hadron interference effects are examined at small and large tt. The methods for the definition of spin-dependent parts of hadron scattering amplitude are presented. The additional contributions to analyzing power ANA_N and the double spin correlation parameter ANNA_{NN} owing to the electromagnetic-hadron interference are determined in the diffraction dip domain of high-energy elastic hadron scattering.Comment: 9 pages, LaTeX, 4 figure

    Using Molecules to Measure Nuclear Spin-Dependent Parity Violation

    Full text link
    Nuclear spin-dependent parity violation arises from weak interactions between electrons and nucleons, and from nuclear anapole moments. We outline a method to measure such effects, using a Stark-interference technique to determine the mixing between opposite-parity rotational/hyperfine levels of ground-state molecules. The technique is applicable to nuclei over a wide range of atomic number, in diatomic species that are theoretically tractable for interpretation. This should provide data on anapole moments of many nuclei, and on previously unmeasured neutral weak couplings

    Magnetocaloric Studies of the Peak Effect in Nb

    Full text link
    We report a magnetocaloric study of the peak effect and Bragg glass transition in a Nb single crystal. The thermomagnetic effects due to vortex flow into and out of the sample are measured. The magnetocaloric signature of the peak effect anomaly is identified. It is found that the peak effect disappears in magnetocaloric measurements at fields significantly higher than those reported in previous ac-susceptometry measurements. Investigation of the superconducting to normal transition reveals that the disappearance of the bulk peak effect is related to inhomogeneity broadening of the superconducting transition. The emerging picture also explains the concurrent disappearance of the peak effect and surface superconductivity, which was reported previously in the sample under investigation. Based on our findings we discuss the possibilities of multicriticality associated with the disappearance of the peak effect.Comment: 30 pages, 10 figure

    Disjoining Potential and Spreading of Thin Liquid Layers in the Diffuse Interface Model Coupled to Hydrodynamics

    Full text link
    The hydrodynamic phase field model is applied to the problem of film spreading on a solid surface. The disjoining potential, responsible for modification of the fluid properties near a three-phase contact line, is computed from the solvability conditions of the density field equation with appropriate boundary conditions imposed on the solid support. The equation describing the motion of a spreading film are derived in the lubrication approximation. In the case of quasi-equilibrium spreading, is shown that the correct sharp-interface limit is obtained, and sample solutions are obtained by numerical integration. It is further shown that evaporation or condensation may strongly affect the dynamics near the contact line, and accounting for kinetic retardation of the interphase transport is necessary to build up a consistent theory.Comment: 14 pages, 5 figures, to appear in PR

    Parity violating pion electroproduction off the nucleon

    Get PDF
    Parity violating (PV) contributions due to interference between γ\gamma and Z0Z^0 exchange are calculated for pion electroproduction off the nucleon. A phenomenological model with effective Lagrangians is used to determine the resulting asymmetry for the energy region between threshold and Δ(1232)\Delta(1232) resonance. The Δ\Delta resonance is treated as a Rarita-Schwinger field with phenomenological NΔN \Delta transition currents. The background contributions are given by the usual Born terms using the pseudovector πN\pi N Lagrangian. Numerical results for the asymmetry are presented.Comment: 17 pages, RevTeX, 6 figures (in separate file figs.uu), uses epsf, accepted for publication in Z. Phys.

    HST Measurements of the Expansion of NGC 6543: Parallax Distance and Nebular Evolution

    Get PDF
    The optical expansion parallax of NGC 6543 has been detected and measured using two epochs of HST images separated by a time baseline of only three years. We have utilized three separate methods of deriving the angular expansion of bright fiducials, the results of which are in excellent agreement. We combine our angular expansion estimates with spectroscopically obtained expansion velocities to derive a distance to NGC 6543 of 1001±\pm269 pc. The deduced kinematic age of the inner bright core of the nebula is 1039±\pm259 years; however, the kinematic age of the polar caps that surround the core is larger - perhaps the result of deceleration or earlier mass ejection. The morphology and expansion patterns of NGC 6543 provide insight into a complex history of axisymmetric, interacting stellar mass ejections.Comment: Accepted for publication in AJ. 18 pages. 6 figure

    Is it still worth searching for lepton flavor violation in rare kaon decays?

    Full text link
    Prospective searches for lepton flavor violation (LFV) in rare kaon decays at the existing and future intermediate-energy accelerators are considered. The proposed studies are complementary to LFV searches in muon-decay experiments and offer a unique opportunity to probe models with approximately conserved fermion-generation quantum number with sensitivity superior to that in other processes. Consequently, new searches for LFV in kaon decays are an important and independent part of the general program of searches for lepton flavor violation in the final states with charged leptons.Comment: 30 pages, 10 figures. An extended version of the talk given at the Chicago Flavor Seminar, February 27, 2004. In the new version some misprints were corrected and some new data for LFV-processes were added. The main content of the paper was not changed. The paper is published in Yad. Fiz. 68, 1272 (2005

    Measuring Higgs boson couplings at the LHC

    Get PDF
    For an intermediate mass Higgs boson with SM-like couplings the LHC allows observation of a variety of decay channels in production by gluon fusion and weak boson fusion. Cross section ratios provide measurements of various ratios of Higgs couplings, with accuracies of order 15% for 100 fb^{-1} of data in each of the two LHC experiments. For Higgs masses above 120 GeV, minimal assumptions on the Higgs sector allow for an indirect measurement of the total Higgs boson width with an accuracy of 10 to 20%, and of the H-->WW partial width with an accuracy of about 10%.Comment: 25 pages, Revtex, 1 figur

    Unresolved H-Alpha Enhancements at High Galactic Latitude in the WHAM Sky Survey Maps

    Full text link
    We have identified 85 regions of enhanced H-Alpha emission at |b| > 10 degrees subtending approximately 1 degree or less on the Wisconsin H-Alpha Mapper (WHAM) sky survey. These high latitude ``WHAM point sources'' have H-Alpha fluxes of 10^{-11} to 10^{-9} erg cm^-2 s^-1, radial velocities within about 70 km/s of the LSR, and line widths that range from less than 20 km/s to about 80 km/s (FWHM). Twenty nine of these enhancements are not identified with either cataloged nebulae or hot stars and appear to have kinematic properties that differ from those observed for planetary nebulae. Another 14 enhancements are near hot evolved low mass stars that had no previously reported detections of associated nebulosity. The remainder of the enhancements are cataloged planetary nebulae and small, high latitude H II regions surrounding massive O and early B stars.Comment: 22 pages, 8 figures, 2 tables, to appear in Feb. 2005 A

    Deformed Algebras from Inverse Schwinger Method

    Full text link
    We consider a problem which may be viewed as an inverse one to the Schwinger realization of Lie algebra, and suggest a procedure of deforming the so-obtained algebra. We illustrate the method through a few simple examples extending Schwinger's su(1,1)su(1,1) construction. As results, various q-deformed algebras are (re-)produced as well as their undeformed counterparts. Some extensions of the method are pointed out briefly.Comment: 14 pages, Jeonju University Report, Late
    • …
    corecore