30,217 research outputs found
Rho Electroproduction and the Hadronic Contribution to Deeply Virtual Compton Scattering
A two-gluon-exchange model incorporating perturbative and non-perturbative
effects is presented for rho electroproduction which provides an excellent
description of all current data. This is then used to calculate the
contribution from the rho to deeply virtual Compton scattering via the
vector-meson-dominance transition rho -> gamma. This is found to be
sufficiently large to provide a significant contribution through interference
with the perturbative QCD term.Comment: 13 pages, 5 figures, 1 tabl
Antioxidant requirements of rats exposed to 100 % oxygen. Part 2 - Effects of dietary ascorbic acid
Dietary ascorbic acid effects as antioxidants in rats exposed to 100 percent oxyge
Throat stability-by pass systems to increase the stable airflow range of a Mach 2.5 inlet with 60-percent internal contraction
The results of an experimental investigation to increase the stable airflow range (without unstart) of a supersonic mixed-compression inlet are presented. Various stability bypass entrances were located on the cowl side of the inlet throat. The types of entrance were distributed porous (normal holes), forward-slanted slot, and distributed educated slots. A large stable airflow range was obtained for each entrance type if a constant pressure was maintained in the stability bypass plenum. The distributed porous entrance provided the largest stable airflow range. Inlet unstart angle of attack was unaffected by the entrances
Distributed educated throat stability bypass to increase the stable airflow range of a Mach 2.5 inlet with 60-percent internal contraction
The results of an experimental investigation to increase the stable airflow operating range of a supersonic mixed-compression inlet are presented. A distributed educated throat stability-bypass entrance configuration was tested. In terms of diffuser-exit corrected airflow, a large inlet stable airflow range of about 16.1 percent was obtained if a constant pressure was maintained in the bypass plenum. Limited unstart angle of attack data are presented
The Chameleonic Contribution to the SZ Radial Profile of the Coma Cluster
We constrain the chameleonic Sunyaev--Zel'dovich (CSZ) effect in the Coma
cluster from measurements of the Coma radial profile presented in the WMAP
7-year results. The CSZ effect arises from the interaction of a scalar (or
pseudoscalar) particle with the cosmic microwave background in the magnetic
field of galaxy clusters. We combine this radial profile data with SZ
measurements towards the centre of the Coma cluster in different frequency
bands, to find Delta T_{SZ,RJ}(0)=-400+/-40 microKelvin and Delta T_{CSZ}^{204
GHz}(0)=-20+/-15 microKelvin (68% CL) for the thermal SZ and CSZ effects in the
cluster respectively. The central value leads to an estimate of the photon to
scalar (or pseudoscalar) coupling strength of g = (5.2 - 23.8) x 10^{-10}
GeV^{-1}, while the 95% confidence bound is estimated to be g < (8.7 - 39.4) x
10^{-10} GeV^{-1}.Comment: 13 pages, 3 figure
Local Inhomogeneity in Asymmetric Simple Exclusion Processes with Extended Objects
Totally asymmetric simple exclusion processes (TASEP) with particles which
occupy more than one lattice site and with a local inhomogeneity far away from
the boundaries are investigated. These non-equilibrium processes are relevant
for the understanding of many biological and chemical phenomena. The
steady-state phase diagrams, currents, and bulk densities are calculated using
a simple approximate theory and extensive Monte Carlo computer simulations. It
is found that the phase diagram for TASEP with a local inhomogeneity is
qualitatively similar to homogeneous models, although the phase boundaries are
significantly shifted. The complex dynamics is discussed in terms of
domain-wall theory for driven lattice systems.Comment: 11 pages, 5 figure
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