18,043 research outputs found
Quasielastic neutrino scattering from oxygen and the atmospheric neutrino problem
We examine several phenomena beyond the scope of Fermi-gas models that affect
the quasielastic scattering (from oxygen) of neutrinos in the 0.1 -- 3.0 GeV
range. These include Coulomb interactions of outgoing protons and leptons, a
realistic finite-volume mean field, and the residual nucleon-nucleon
interaction. None of these effects are accurately represented in the Monte
Carlo simulations used to predict event rates due to and neutrinos
from cosmic-ray collisions in the atmosphere. We nevertheless conclude that the
neglected physics cannot account for the anomalous to ratio observed
at Kamiokande and IMB, and is unlikely to change absolute event rates by more
than 10--15\%. We briefly mention other phenomena, still to be investigated in
detail, that may produce larger changes.Comment: In Revtex version 2. 14 pages, 3 figures (available on request from
J. Engel, tel. 302-831-4354, [email protected]
Shape transformations in rotating ferrofluid drops
Floating drops of magnetic fluid can be brought into rotation by applying a
rotating magnetic field. We report theoretical and experimental results on the
transition from a spheroid equilibrium shape to non-axissymmetrical three-axes
ellipsoids at certain values of the external field strength. The transitions
are continuous for small values of the magnetic susceptibility and show
hysteresis for larger ones. In the non-axissymmetric shape the rotational
motion of the drop consists of a vortical flow inside the drop combined with a
slow rotation of the shape. Nonlinear magnetization laws are crucial to obtain
quantitative agreement between theory and experiment.Comment: 4 pages, 3 figure
Semi-analytic approximations for production of atmospheric muons and neutrinos
Simple approximations for fluxes of atmospheric muons and muon neutrinos are
developed which display explicitly how the fluxes depend on primary cosmic ray
energy and on features of pion production. For energies of approximately 10 GeV
and above the results are sufficiently accurate to calculate response functions
and to use for estimates of systematic uncertainties.Comment: 15 pages with 8 figure
SRB ascent aerodynamic heating design criteria reduction study, volume 1
An independent set of solid rocket booster (SRB) convective ascent design environments were produced which would serve as a check on the Rockwell IVBC-3 environments used to design the ascent phase of flight. In addition, support was provided for lowering the design environments such that Thermal Protection System (TPS), based on conservative estimates, could be removed leading to a reduction in SRB refurbishment time and cost. Ascent convective heating rates and loads were generated at locations in the SRB where lowering the thermal environment would impact the TPS design. The ascent thermal environments are documented along with the wind tunnel/flight test data base used as well as the trajectory and environment generation methodology. Methodology, as well as, environment summaries compared to the 1980 Design and Rockwell IVBC-3 Design Environment are presented in this volume, 1
Calculation of conventional and prompt lepton fluxes at very high energy
An efficient method for calculating inclusive conventional and prompt
atmospheric leptons fluxes is presented. The coupled cascade equations are
solved numerically by formulating them as matrix equation. The presented
approach is very flexible and allows the use of different hadronic interaction
models, realistic parametrizations of the primary cosmic-ray flux and the
Earth's atmosphere, and a detailed treatment of particle interactions and
decays. The power of the developed method is illustrated by calculating lepton
flux predictions for a number of different scenarios.Comment: 8 pages, 10 figures, for Proceedings of the International Symposium
for Very-High Energy Cosmic-Ray Interactions (ISVHECRI 2014
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