17,762 research outputs found
Unstable manifolds and Schroedinger dynamics of Ginzburg-Landau vortices
The time evolution of several interacting Ginzburg-Landau vortices according
to an equation of Schroedinger type is approximated by motion on a
finite-dimensional manifold. That manifold is defined as an unstable manifold
of an auxiliary dynamical system, namely the gradient flow of the
Ginzburg-Landau energy functional. For two vortices the relevant unstable
manifold is constructed numerically and the induced dynamics is computed. The
resulting model provides a complete picture of the vortex motion for arbitrary
vortex separation, including well-separated and nearly coincident vortices.Comment: 23 pages amslatex, 5 eps figures, minor typos correcte
An investigation of the suitability of white rats for sub-orbital studies of behavior in a gravity field
Suitability of white rats for suborbital studies of behavior in gravity field
The application of Floquet theory to the computation of small orbital perturbations over long time intervals using the Tschauner- Hempel equations
Calculation of path deviation of satellite from reference trajectory - perturbation theor
On the engineering portion of a research program to develop a zero-g, drag-free satellite and to perform a gyro test of general relativity in a satellite Fourth semiannual status report
Zero gravity satellite concept feasibility and control system design evaluation using air cushion vehicl
Develop a zero-G drag-free satellite and perform a gyro test of general relativity in a satellite Semiannual status report, Nov. 1965 - Apr. 1966
Aeronomy experiment satellite polar orbit, control analysis, and control simulatio
Form Factors from Light-Cone Sum Rules with B-Meson Distribution Amplitudes
New sum rules for and form factors are derived
from the correlation functions expanded near the light-cone in terms of B-meson
distribution amplitudes. The contributions of quark-antiquark and
quark-antiquark-gluon components in the B meson are taken into account. Models
for the B-meson three-particle distribution amplitudes are suggested, based on
QCD sum rules in HQET. Employing the new light-cone sum rules we calculate the
form factors at small momentum transfers, including violation
effects. The results agree with the predictions of the conventional light-cone
sum rules.Comment: 32 pages, 7 figures, the discussion of numerical results extended,
two references added, version to be published in Phys.Rev.
On the engineering portion of a research program - To perform a gyro test of general relativity in a satellite and develop associated control technology
Satellite attitude control using gyro-telescope structure driven by superconducting actuato
B-Meson Distribution Amplitudes of Geometric Twist vs. Dynamical Twist
Two- and three-particle distribution amplitudes of heavy pseudoscalar mesons
of well-defined geometric twist are introduced. They are obtained from
appropriately parametrized vacuum-to-meson matrix elements by applying those
twist projectors which determine the enclosed light-cone operators of definite
geometric twist and, in addition, observing the heavy quark constraint.
Comparing these distribution amplitudes with the conventional ones of dynamical
twist we derive relations between them, partially being of Wandzura-Wilczek
type; also sum rules of Burkhardt-Cottingham type are derived.The derivation is
performed for the (double) Mellin moments and then re-summed to the non-local
distribution amplitudes. Furthermore, a parametrization of vacuum-to-meson
matrix elements for non-local operators off the light-cone in terms of
distribution amplitudes accompanying independent kinematical structures is
derived.Comment: 18 pages, Latex 2e, no figure
Module production of the one-arm AFP 3D pixel tracker
The ATLAS Forward Proton (AFP) detector is designed to identify events in
which one or two protons emerge intact from the LHC collisions. AFP will
consist of a tracking detector, to measure the momentum of the protons, and a
time of flight system to reduce the background from multiple proton-proton
interactions. Following an extensive qualification period, 3D silicon pixel
sensors were selected for the AFP tracker. The sensors were produced at CNM
(Barcelona) during 2014. The tracker module assembly and quality control was
performed at IFAE during 2015. The assembly of the first AFP arm and the
following installation in the LHC tunnel took place in February 2016. This
paper reviews the fabrication process of the AFP tracker focusing on the pixel
modules.Comment: PIXEL 2016 proceedings; Submitted to JINS
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