1,742 research outputs found

    A Contribution of the Trivial Connection to Jones Polynomial and Witten's Invariant of 3d Manifolds I

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    We use the Chern-Simons quantum field theory in order to prove a recently conjectured limitation on the 1/K expansion of the Jones polynomial of a knot and its relation to the Alexander polynomial. This limitation allows us to derive a surgery formula for the loop corrections to the contribution of the trivial connection to Witten's invariant. The 2-loop part of this formula coincides with Walker's surgery formula for Casson-Walker invariant. This proves a conjecture that Casson-Walker invariant is a 2-loop correction to the trivial connection contribution to Witten's invariant of a rational homology sphere. A contribution of the trivial connection to Witten's invariant of a manifold with nontrivial rational homology is calculated for the case of Seifert manifolds.Comment: 28 page

    S-wave charmed mesons in lattice NRQCD

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    Heavy-light mesons can be studied using the 1/M expansion of NRQCD, provided the heavy quark mass is sufficiently large. Calculations of the S-wave charmed meson masses from a classically and tadpole-improved action are presented. A comparison of O(1/M), O(1/M^2) and O(1/M^3) results allows convergence of the expansion to be discussed. It is shown that the form of discretized heavy quark propagation must be chosen carefully.Comment: LATTICE98(heavyqk), 3 pages including 3 figure

    A multi-band printed monopole antenna

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    In this paper, we present an antenna design for multiband applications which can cover the GSM 900 (890-960 MHz), DCS (1710– 1880 MHz) and PCS (1850–1990 MHz), UMTS (1920– 2170 MHz), and WLAN2.4GHz (2400-2484MHz) frequency bands. A prototype is built and measured. Results of return loss, radiation patterns, and efficiency are given. The antenna is small, cheap to manufacture, has a low profile and would be suitable for wearable applications, mobile phones and base stations

    Modified Paschos-Wolfenstein relation and extraction of weak mixing angle sin^2 theta_W

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    The NuTeV collaboration reported anomalously large weak mixing angle sin^2 theta_W in comparison with the standard model prediction. Neutrino and antineutrino charged- and neutral-current events are analyzed for extracting sin^2 theta_W. Although the Paschos-Wolfenstein relation is not directly used in the analysis, it plays an important role in the determination. Noting that the target nucleus, iron, is not an isoscalar nucleus, we derive a leading-order expression for a modified Paschos-Wolfenstein relation for nuclei, which may have neutron excess. Then, using charge and baryon-number conservations for nuclei, we discuss a nuclear correction in the sin^2 theta_W determination. It is noteworthy that nuclear modifications are different between valence up- and down-quark distributions. We show this difference effect on the NuTeV sin^2 theta_W deviation.Comment: 5 pages, REVTeX4.0, revtex4.cls, url.sty, natbib.sty, revsymb.sty, 10pt.rtx, aps.rtx, amssymb.sty, amsfonts.sty, 3 eps figures. Phys. Rev. D in press. Email: [email protected] See also http://hs.phys.saga-u.ac.j

    Measuring the ΜΌ\nu_{\mu} to ΜΌˉ\bar{\nu_{\mu}} Ratio in a High Statistics Atmospheric Neutrino Experiment

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    By exploiting differences in muon lifetimes it is possible to distinguish ΜΌ\nu_{\mu} from ΜΌˉ\bar{\nu_{\mu}} charged current interactions in underground neutrino detectors. Such observations would be a useful tool in understanding the source of the atmospheric neutrino anomaly.Comment: 6 pages no figure

    A study of perturbations in linear and circular polarized antennas in close proximity to the human body and a dielectric liquid filled phantom at 1.8 GHz

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    In the design and synthesis of wearable antennas isolation distance from the body is a critical parameter. This paper deals with the comparison of perturbations caused to the matching of simple linear and circular polarized patch antennas due to the close proximity of a human torso and rectangular box phantom filled with muscle simulating liquid at 1.8GHz. The isolated variable is return loss (S11). Results show that both linear and circularly polarized antennas produce an optimal return loss closer to the surface of a typical phantom than the back of a human volunteer

    The leading particle effect from light quark fragmentation in charm hadroproduction

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    The asymmetry of D−D^- and D+D^+ meson production in π−N\pi^-N scattering observed by the E791 experiment is a typical phenomenon known as the leading particle effect in charm hadroproducton. We show that the phenomenon can be explained by the effect of light quark fragmentation into charmed hadrons (LQF). Meanwhile, the size of the LQF effect is estimated from data of the E791 experiment. A comparison is made with the estimate of the LQF effect from prompt like-sign dimuon rate in neutrino experiments. The influence of the LQF effect on the measurement of nucleon strange distribution asymmetry from charged current charm production processes is briefly discussed.Comment: 6 latex pages, 1 figure, to appear in EPJ

    Evidence for SU(3) symmetry breaking from hyperon production

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    We examine the SU(3) symmetry breaking in hyperon semileptonic decays (HSD) by considering two typical sets of quark contributions to the spin content of the octet baryons: Set-1 with SU(3) flavor symmetry and Set-2 with SU(3) flavor symmetry breaking in HSD. The quark distributions of the octet baryons are calculated with a successful statistical model. Using an approximate relation between the quark fragmentation functions and the quark distributions, we predict polarizations of the octet baryons produced in e+e−e^+e^- annihilation and semi-inclusive deeply lepton-nucleon scattering in order to reveal the SU(3) symmetry breaking effect on the spin structure of the octet baryons. We find that the SU(3) symmetry breaking significantly affects the hyperon polarization. The available experimental data on the Λ\Lambda polarization seem to favor the theoretical predictions with SU(3) symmetry breaking. We conclude that there is a possibility to get a collateral evidence for SU(3) symmetry breaking from hyperon production. The theoretical errors for our predictions are discussed.Comment: 3 tables, 14 figure

    Numerical study of multilayer adsorption on fractal surfaces

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    We report a numerical study of van der Waals adsoprtion and capillary condensation effects on self-similar fractal surfaces. An assembly of uncoupled spherical pores with a power-law distributin of radii is used to model fractal surfaces with adjustable dimensions. We find that the commonly used fractal Frankel-Halsey-Hill equation systematically fails to give the correct dimension due to crossover effects, consistent with the findings of recent experiments. The effects of pore coupling and curvature dependent surface tension were also studied.Comment: 11 pages, 3 figure
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