707 research outputs found
Review of \u3cem\u3eMafias on the Move: How Organized Crime Conquers New Territories,\u3c/em\u3e by Federico Varese
An âUntrammeled Rightâ? The McCarran Immigration Subcommittee and the Origins of Presidential Authority to Suspend and Restrict Alien Entry Under §1182(f)
The language of Section 212(e) of the 1952 Immigration and Nationality Act, 8 U.S.C. §1182(f), contains a sweeping authorization of presidential discretion to suspend and restrict alien entry into the United States. Senator Pat McCarran (D-NV) first introduced the subsection in 1950 as part of the omnibus immigration bill drafted by his Judiciary Committeeâs immigration subcommittee. The specific origins of the language and the original intent behind the subsection remain missing pieces in the extensive scholarly literature on the 1952 INA and legislative history as explored by the courts. This article reveals that the subcommittee modeled the subsection on the sixth proviso of the 1917 Immigration Act, the May 1918 Wartime Measure, and a selective interpretation of Supreme Court precedent. The article reveals further that the original intent behind the subsection was to close perceived loopholes in existing law enabling entry by displaced persons and Communist governmental officials
Light Front Theory Of Nuclear Matter
A relativistic light front formulation of nuclear dynamics is applied to
infinite nuclear matter. A hadronic meson-baryon Lagrangian, consistent with
chiral symmetry, leads to a nuclear eigenvalue problem which is solved,
including nucleon-nucleon (NN) correlations, in the one-boson-exchange
approximation for the NN potential. The nuclear matter saturation properties
are reasonably well reproduced, with a compression modulus of 180 MeV. We find
that there are about 0.05 excess pions per nucleon.Comment: 6 pages, Revtex, one figure; version resubmitted to Phys. Lett.
Medium Effects in rho-Meson Photoproduction
We compute dilepton invariant mass spectra from the decays of rho mesons
produced by photon reactions off nuclei. Our calculations employ a realistic
model for the rho photoproduction amplitude on the nucleon which provides fair
agreement with measured cross sections. Medium effects are implemented via an
earlier constructed rho propagator based on hadronic many-body theory. At
incoming photon energies of 1.5 -3 GeV as used by the CLAS experiment at JLAB,
the average density probed for iron targets is estimated at about half
saturation density. At the pertinent rho-meson 3-momenta the predicted medium
effects on the rho propagator are rather moderate. The resulting dilepton
spectra approximately agree with recent CLAS data.Comment: One numerical error corrected, conclusions unchange
Many-Body Corrections to Charged-Current Neutrino Absorption Rates in Nuclear Matter
Including nucleon--nucleon correlations due to both Fermi statistics and
nuclear forces, we have developed a general formalism for calculating the
charged--current neutrino--nucleon absorption rates in nuclear matter. We find
that at one half nuclear density many--body effects alone suppress the rates by
a factor of two and that the suppression factors increase to 5 at
g cm. The associated increase in the neutrino--matter
mean--free--paths parallels that found for neutral--current interactions and
opens up interesting possibilities in the context of the delayed supernova
mechanism and protoneutron star cooling.Comment: 11 pages, APS REVTeX format, 1 PostScript figure, uuencoded
compressed, and tarred, submitted to Physical Review Letter
Low-momentum interactions for nuclei
We show how the renormalization group is used to construct a low-momentum
nucleon-nucleon interaction V_{low k}, which unifies all potential models used
in nuclear structure calculations. V_{low k} can be directly applied to the
nuclear shell model or to nucleonic matter without a G matrix resummation. It
is argued that V_{low k} parameterizes a high-order chiral effective field
theory two-nucleon force. We use cutoff dependence as a tool to assess the
error in the truncation of nuclear forces to two-nucleon interactions and
introduce a low-momentum three-nucleon force, which regulates A=3,4 binding
energies. The adjusted three-nucleon interaction is perturbative for small
cutoffs. In contrast to other precision interactions, the error due to missing
many-body forces can be estimated, when V_{low k} and the corresponding
three-nucleon force are used in nuclear structure calculations and the cutoff
is varied.Comment: 10 pages, 5 figures, talk at INT workshop on Nuclear Forces and the
Quantum Many-Body Problem, Seattle, October 200
Neutrino and axion emissivities of neutron stars from nucleon-nucleon scattering data
Neutrino and axion production in neutron stars occurs mainly as
bremsstrahlung from nucleon-nucleon (NN) scattering. The energy radiated via
neutrinos or axions is typically very small compared to other scales in the
two-nucleon system. The rate of emission of such "soft" radiation is directly
related to the on-shell NN amplitude, and thereby to the NN experimental data.
This facilitates the model-independent calculation of the neutrino and axion
radiation rates which is presented here. We find that the resultant rates are a
factor of four below earlier estimates based on a one-pion-exchange NN
amplitude.Comment: 5 pages, 2 figures, revtex, uses epsfig.sty. Revised version has
minor modifications to the text and references, as well as some changes to
the numerical results. The conclusions are unchange
Modern nucleon-nucleon potentials and symmetry energy in infinite matter
We study the symmetry energy in infinite nuclear matter employing a
non-relativistic Brueckner-Hartree-Fock approach and using various new
nucleon-nucleon (NN) potentials, which fit np and pp scattering data very
accurately. The potential models we employ are the recent versions of the
Nijmegen group, Nijm-I, Nijm-II and Reid93, the Argonne potential and
the CD-Bonn potential. All these potentials yield a symmetry energy which
increases with density, resolving a discrepancy that existed for older NN
potentials. The origin of remaining differences is discussed.Comment: 17 pages, 10 figures included, elsevier latex style epsart.st
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Fresh perspectives on customer experience
Purpose
â The purpose of this paper is to provide directions for future research on: broadening the role of customers in customer experience; taking a practice-based approach to customer experience; and recognizing the holistic, dynamic nature of customer experience across all touch points and over time.
Design/methodology/approach
â The approach is conceptual identifying current gaps in research on customer experience.
Findings
â The findings include a set of research questions and research agenda for future research on customer experience.
Originality/value
â This research suggests fresh perspectives for understanding the customer experience which can inspire future research and advance theory and managerial practice
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