1,742 research outputs found
A Contribution of the Trivial Connection to Jones Polynomial and Witten's Invariant of 3d Manifolds I
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
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
In this paper, we present an antenna design for multiband
applications which can cover the GSM 900 (890-960 MHz),
DCS (1710â 1880 MHz) and PCS (1850â1990 MHz), UMTS (1920â
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
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 to Ratio in a High Statistics Atmospheric Neutrino Experiment
By exploiting differences in muon lifetimes it is possible to distinguish
from 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
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
The asymmetry of and meson production in 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
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 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 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
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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