7,844 research outputs found
On the Symmetric Space Sigma-Model Kinematics
The solvable Lie algebra parametrization of the symmetric spaces is
discussed. Based on the solvable Lie algebra gauge two equivalent formulations
of the symmetric space sigma model are studied. Their correspondence is
established by inspecting the normalization conditions and deriving the field
transformation laws.Comment: 17 page
coupling constant in light cone QCD sum rules
We employ the light cone QCD sum rules to calculate coupling
constant by studying the two point correlation function between the vacuum and
the pion state. Our result is consistent with the traditional QCD sum rules
calculations and it is in agreement with the experimental value.Comment: 8 pages, latex, 2 figure
Symmetric space sigma-model dynamics: Current formalism
After explicitly constructing the symmetric space sigma model lagrangian in
terms of the coset scalars of the solvable Lie algebra gauge in the current
formalism we derive the field equations of the theory.Comment: 10 page
g_phi-pion-gamma coupling constant in light cone QCD sum rules
The coupling constant of g_phi-pion-gamma decay is calculated using light
cone QCD sum rules. A comparison of our result with the ones existing in the
literature is presented.Comment: 9 pages, 2 figure
Mechanics of soil erosion from overland flow generated by simulated rainfall
September 1973.Bibliography: pages 53-54
Study of Eclipsing Binary and Multiple Systems in OB Associations II. The Cygnus OB Region: V443 Cyg, V456 Cyg and V2107 Cyg
Three presumably young eclipsing binary systems in the direction of the
Cygnus OB1, OB3 and OB9 associations are studied. Component spectra are
reconstructed and their orbits are determined using light curves and spectra
disentangling techniques. V443 Cyg and V456 Cyg have circular orbits, while the
light curve of V2107\,Cyg imposes a slightly eccentric orbit
(. V443 Cyg harbours F-type stars, and not young early-A stars
as previously suggested in the literature based on photometry solely. It
appears to be situated in the foreground (distance kpc) of the
young stellar populations in Cygnus. V456 Cyg, at a distance of
kpc consists of a slightly metal-weak A--type and an early--F star. The age of
both systems, on or very near to the main sequence, remains uncertain by an
order of magnitude. V2107 Cyg is a more massive system ( and
) at kpc and, also kinematically, a strong
candidate-member of Cyg OB1. The more massive component is slightly evolved and
appears to undergo non-radial -type pulsations. The Doppler signal
of the secondary is barely detectable. A more extensive study is important to
fix masses more precisely, and an asteroseismological study would then become
appropriate. Nevertheless, the position of the primary in the HR-diagram
confines the age already reasonably well to Myr, indicating for Cyg
OB1 a similar extent of star formation history as established for Cyg OB2.Comment: 27 pages, including 9 figures and 6 tables, accepted for publication
in Astronomical Journa
Subintimal Double-Barrel Restenting of an Occluded Primary Stented Superficial Femoral Artery
In-stent re-stenosis is a frequent complication of endovascular stents, especially in the superficial femoral artery (SFA). Endovascular re-intervention of in- or peri-stent occlusive disease consists of recanilization through the occluded stent. In our case report, we describe the endovascular treatment of a previously placed stent in the SFA. We unintentionally passed the affected stent subintimally, in a double barrel fashion next to the first stent. The procedure was without any complications and with a successfull angiographic result. At one year follow-up the patient still has no complaints and the stent is still patent
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