219 research outputs found
Sedimentary geology of the Middle Carboniferous of the Donbas region (Dniepr-Donets basin, Ukraine)
Peer reviewedPublisher PD
Proton Scattering from 206-Pb: Neutron Densities in the Nuclear Interior
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Neutrino Clustering in the Galaxy with a Global Monopole
In spherically symmetric, static spacetime, we show that only j=1/2 fermions
can satisfy both Einstein's field equation and Dirac's equation. It is also
shown that neutrinos are able to have effective masses and cluster in the
galactic halo when they are coupled to a global monopole situated at the
galactic core. Astronomical implications of the results are discussed.Comment: 8 pages, Revtex
Energy Dependence of the NN t-matrix in the Optical Potential for Elastic Nucleon-Nucleus Scattering
The influence of the energy dependence of the free NN t-matrix on the optical
potential of nucleon-nucleus elastic scattering is investigated within the
context of a full-folding model based on the impulse approximation. The
treatment of the pole structure of the NN t-matrix, which has to be taken into
account when integrating to negative energies is described in detail. We
calculate proton-nucleus elastic scattering observables for O,
Ca, and Pb between 65 and 200 MeV laboratory energy and study
the effect of the energy dependence of the NN t-matrix. We compare this result
with experiment and with calculations where the center-of-mass energy of the NN
t-matrix is fixed at half the projectile energy. It is found that around 200
MeV the fixed energy approximation is a very good representation of the full
calculation, however deviations occur when going to lower energies (65 MeV).Comment: 11 pages (revtex), 6 postscript figure
The Higgs resonance shape in gluon fusion: Heavy Higgs effects
We study the influence of two--loop radiative corrections of enhanced
electroweak strength on Higgs production at the LHC. We consider Higgs
production by the gluon fusion mechanism, with the subsequent decay of the
Higgs boson into a pair of Z bosons, and incorporate the resonance shape
corrections up to order . We take into account the
full process and the
background, as well as the subsequent decay of the Z pair into leptons. We also
discuss the theoretical uncertainty related to the use of the equivalence
theorem in this process
Performance of a Neutron Polarimeter to Measure the Electric Form Factor of the Neutron
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Calibration of a Neutron Polarimeter
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Six Years of Chandra Observations of Supernova Remnants
We present a review of the first six years of Chandra X-ray Observatory
observations of supernova remnants. From the official "first-light" observation
of Cassiopeia A that revealed for the first time the compact remnant of the
explosion, to the recent million-second spectrally-resolved observation that
revealed new details of the stellar composition and dynamics of the original
explosion, Chandra observations have provided new insights into the supernova
phenomenon. We present an admittedly biased overview of six years of these
observations, highlighting new discoveries made possible by Chandra's unique
capabilities.Comment: 82 pages, 28 figures, for the book Astrophysics Update
Towards an understanding of neuroscience for science educators
Advances in neuroscience have brought new insights to the development of cognitive functions. These data are of considerable interest to educators concerned with how students learn. This review documents some of the recent findings in neuroscience, which is richer in describing cognitive functions than affective aspects of learning. A brief overview is presented here of the techniques used to generate data from imaging and how these findings have the possibility to inform educators. There are implications for considering the impact of neuroscience at all levels of education – from the classroom teacher and practitioner to policy. This relatively new cross-disciplinary area of research implies a need for educators and scientists to engage with each other. What questions are emerging through such dialogues between educators and scientists are likely to shed light on, for example, reward, motivation, working memory, learning difficulties, bilingualism and child development. The sciences of learning are entering a new paradigm
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