10,335 research outputs found
Mariner Venus 67 guidance and control system
Subsystems of Mariner Venus 67 spacecraft guidance and control syste
Deuteron Electromagnetic Properties with a Poincar\'e-Covariant Current Operator within Front-Form Hamiltonian Dynamics
Deuteron elastic and deep inelastic electromagnetic properties have been
studied within the front-form Hamiltonian dynamics, using a
Poincar\'e-covariant current operator. The deuteron elastic form factors are
strongly sensitive to different realistic interactions, while the
relevance of different nucleon form factor models is huge for , weak
for and negligible for the tensor polarization. The possibility to
gain information on the neutron charge form factor from an analysis of
has been investigated. The extraction of the neutron structure functions from
the deuteron deep inelastic structure functions at high is largely affected
by the use of our Poincar\'e-covariant relativistic approach instead of the
usual impulse approximation within an instant-form approach.Comment: 12 pages, World-Scientific macro included. Proc. VIII Conf. on
"Problems in Theoretical Nuclear Physics", Cortona (Italy) Oct. 18-20, 2000.
(World Scientific, Fall 2001
Neutron unpolarized structure function F_2^n(x) from deep inelastic scattering off ^{3}He and ^{3}H
The possibility to safely extract the neutron deep inelastic structure
function in the range from joint measurements of
deep inelastic structure functions of and is demonstrated.
While the nuclear structure effects are relevant, the model dependence in this
extraction linked to the interaction is shown to be weak.Comment: 5 pages. Proc. XVIIth Conf. on "Few-Body Problems in Physics", Evora(
Portugal) Sept. 11, 2000. To appear in Nucl. Phys.
A Study of Final State Effects in the electrodisintegration of a polarized Helium-3 target
An approach for the description of the final state interaction in the
evaluation of inclusive electromagnetic responses of a polarized Helium-3
target, is briefly illustrated. Preliminary results of calculations, where the
final state interaction is fully taken into account for the two-body break-up
channel, are compared with experimental data, showing a very encouraging
improvement with respect to the plane wave impulse approximation results.Comment: 8 pages. Proc. of "GDH 2004", Old Dominion University, Norfolk, Va,
June 2-5, 2004. Class file "ws-procs9x6.cls" and style file "rotating_pr.sty"
include
Sun direction detection system
One of the detectors is an illumination detector consisting of two spaced apart elongated strips with a strip of cadmium sulphide (Cds) deposited therebetween. Whenever the line image impinges the CdS strip, the resistance between the two other strips is relatively low, while being high when the line image is outside the field of view of the illumination detector. Also included is a sun angle detector which consists of a vapor deposited resistor strip connected at one end to plus 10v and at the other end to minus 10v. Spaced apart from the resistor strip is an elongated strip of low resistance material acting as an output strip, with a CdS strip between the two strips. When the line image is within the field of view of the sun angle detector, the output voltage at the output strip depends on the position of the line image across the sun angle detector
Pion Generalized Parton Distributions within a fully covariant constituent quark model
We extend the investigation of the Generalized Parton Distribution for a
charged pion within a fully covariant constituent quark model, in two respects:
(i) calculating the tensor distribution and (ii) adding the treatment of the
evolution, needed for achieving a meaningful comparison with both the
experimental parton distribution and the lattice evaluation of the so-called
generalized form factors. Distinct features of our phenomenological covariant
quark model are: (i) a 4D Ansatz for the pion Bethe-Salpeter amplitude, to be
used in the Mandelstam formula for matrix elements of the relevant current
operators, and (ii) only two parameters, namely a quark mass assumed to hold
MeV and a free parameter fixed through the value of the pion decay
constant. The possibility of increasing the dynamical content of our covariant
constituent quark model is briefly discussed in the context of the Nakanishi
integral representation of the Bethe-Salpeter amplitude.Comment: Pages 20, figure 11 and table 8. Minor changes. To be published in
EPJ
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