3,690 research outputs found
Requirements Study for System Implementation of an Atmospheric Laser Propagation Experiment Program, Volume II
Program planning, ground support and airborne equipment for laser space communication syste
Partonic Energy Loss and the Drell-Yan Process
We examine the current status of the extraction of the rate of partonic
energy loss in nuclei from A dependent data. The advantages and difficulties of
using the Drell-Yan process to measure the energy loss of a parton traversing a
cold nuclear medium are discussed. The prospects of using relatively low energy
proton beams for a definitive measurement of partonic energy loss are
presented.Comment: 12 pages, 2 figure
Parity-Violating Electron Scattering and Neucleon Structure
The measurement of parity violation in the helicity dependence of
electron-nucleon scattering provides unique information about the basic quark
structure of the nucleons. In this review, the general formalism of
parity-violating electron scattering is presented, with emphasis on elastic
electron-nucleon scattering. The physics issues addressed by such experiments
is discussed, and the major goals of the presently envisioned experimental
program are identified. %General aspects of the experimental technique are
reviewed and A summary of results from a recent series of experiments is
presented and the future prospects of this program are also discussed.Comment: 45 pages, 9 figure
Probing Nucleon Strangeness with Neutrinos: Nuclear Model Dependences
The extraction of the nucleon's strangeness axial charge, Delta_s, from
inclusive, quasielastic neutral current neutrino cross sections is studied
within the framework of the plane-wave impulse approximation. We find that the
value of Delta_s can depend significantly on the choice of nuclear model used
in analyzing the quasielastic cross section. This model-dependence may be
reduced by one order of magnitude when Delta_s is extracted from the ratio of
total proton to neutron yields. We apply this analysis to the interpretation of
low-energy neutrino cross sections and arrive at a nuclear theory uncertainty
of plus/minus 0.03 on the value of Delta_s expected to be determined from the
ratio of proton and neutron yields measured by the LSND collaboration. This
error compares favorably with estimates of the SU(3)-breaking uncertainty in
the value of Delta_s extracted from inclusive, polarized deep-inelastic
structure function measurements. We also point out several general features of
the quasielastic neutral current neutrino cross section and compare them with
the analogous features in inclusive, quasielastic electron scattering.Comment: 40 pages (including 11 postscript figures), uses REVTeX and
epsfig.st
Electrocardiographic diagnosis of ST segment elevation myocardial infarction: An evaluation of three automated interpretation algorithms
To assess the validity of three different computerized electrocardiogram (ECG) interpretation algorithms in correctly identifying STEMI patients in the prehospital environment who require emergent cardiac intervention
Strangeness in the nucleon and the ratio of proton-to-neutron neutrino-induced quasi-elastic yield
The electroweak form factors of the nucleon as obtained within a three flavor
pseudoscalar vector meson soliton model are employed to predict the ratio of
the proton and neutron yields from , which are induced by quasi-elastic
neutrino reactions. These predictions are found to vary only moderately in the
parameter space allowed by the model. The antineutrino flux of the up-coming
experiment determining this ratio was previously overestimated. The
corresponding correction is shown to have only a small effect on the predicted
ratio. However, it is found that the experimental result for the ratio
crucially depends on an accurate measurement of the energy of the knocked out
nucleon.Comment: 17 pages, LaTeX, 2 tables, 4 figures, Discussion on shape of strange
form factors added, Z. Phys. A, to be publishe
Garvey-Kelson Relations for Nuclear Charge Radii
The Garvey-Kelson relations (GKRs) are algebraic expressions originally
developed to predict nuclear masses. In this letter we show that the GKRs
provide a fruitful framework for the prediction of other physical observables
that also display a slowly-varying dynamics. Based on this concept, we extend
the GKRs to the study of nuclear charge radii. The GKRs are tested on 455 out
of the approximately 800 nuclei whose charge radius is experimentally known. We
find a rms deviation between the GK predictions and the experimental values of
only 0.01 fm. This should be contrasted against some of the most successful
microscopic models that yield rms deviations almost three times as large.
Predictions - with reliable uncertainties - are provided for 116 nuclei whose
charge radius is presently unknown.Comment: 4 pages and 3 figure
Relativistic nuclear structure effects in quasielastic neutrino scattering
Charged-current cross sections are calculated for quasielastic neutrino and
antineutrino scattering using a relativistic meson-nucleon model. We examine
how nuclear-structure effects, such as relativistic random-phase-approximation
(RPA) corrections and momentum-dependent nucleon self-energies, influence the
extraction of the axial form factor of the nucleon. RPA corrections are
important only at low-momentum transfers. In contrast, the momentum dependence
of the relativistic self-energies changes appreciably the value of the
axial-mass parameter, , extracted from dipole fits to the axial form
factor. Using Brookhaven's experimental neutrino spectrum we estimate the
sensitivity of M to various relativistic nuclear-structure effects.Comment: 26 pages, revtex, 6 postscript figures (available upon request
Why, what, and how? case study on law, risk, and decision making as necessary themes in built environment teaching
The paper considers (and defends) the necessity of including legal studies as a core part of built environment undergraduate and postgraduate curricula. The writer reflects upon his own experience as a lawyer working alongside and advising built environment professionals in complex land remediation and site safety management situations in the United Kingdom and explains how themes of liability, risk, and decision making can be integrated into a practical simulation in order to underpin more traditional lecture-based law teaching. Through reflection upon the writer's experiments with simulation-based teaching, the paper suggests some innovations that may better orientate law teaching to engage these themes and, thereby, enhance the relevance of law studies to the future needs of built environment professionals in practice.</p
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