14,365 research outputs found
Combining weak and strong lensing in cluster potential reconstruction
We propose a method for recovering the two-dimensional gravitational
potential of galaxy clusters which combines data from weak and strong
gravitational lensing. A first estimate of the potential from weak lensing is
improved at the approximate locations of critical curves. The method can be
fully linearised and does not rely on the existence and identification of
multiple images. We use simulations to show that it recovers the surface-mass
density profiles and distributions very accurately, even if critical curves are
only partially known and if their location is realistically uncertain. We
further describe how arcs at different redshifts can be combined, and how
deviations from weak lensing can be included.Comment: 9 pages, 5 figures, A&A in press, changes to match the accepted
versio
Constraining the CKM Parameters using CP Violation in semi-leptonic B Decays
We discuss the usefulness of the CP violating semi-leptonic asymmetry a_{SL}
not only as a signal of new physics, but also as a tool in constraining the CKM
parameters. We show that this technique could yield useful results in the first
years of running at the B factories. We present the analysis graphically in
terms of M_{12}, the dispersive part of the B-Bbar mixing amplitude. This is
complementary to the usual unitarity triangle representation and often allows a
cleaner interpretation of the data.Comment: 15 pages REVTEX, 7 figure
Marijuana and Youth
This paper contains the first estimates of the price sensitivity of the prevalence of youth marijuana use. Survey data on marijuana use by high school seniors from the Monitoring the Future Project are combined with data on marijuana prices and potency from the Drug Enforcement Administration Office of Intelligence or Intelligence Division. Our estimates of the price elasticity of annual marijuana participation range from 0.06 to 0.47, while those for thirty day participation range from 0.002 to 0.69. These estimates clearly imply that changes in the real, quality adjusted price of marijuana contributed significantly to the trends in youth marijuana use between 1982 and 1998, particularly during the contraction in use from 1982 to 1992. Similarly, changes in youth perceptions of the harms associated with regular marijuana use had a substantial impact on both the contraction in use during the 1982 though 1992 period and the subsequent expansion in use after 1992. These findings underscore the usefulness of considering price in addition to more traditional determinants in any analysis of marijuana consumption decisions made by youths.
Sneutrino-Antisneutrino Mixing and Neutrino Mass in Anomaly--mediated Supersymmetry Breaking Scenario
In supersymmetric models with nonzero Majorana neutrino mass, the sneutrino
and antisneutrino mix, which may lead to same sign dilepton signals in future
collider experiments. We point out that the anomaly-mediated supersymmetry
breaking scenario has a good potential to provide an observable rate of such
signals for the neutrino masses suggested by the atmospheric and solar neutrino
oscillations. The sneutrino mixing rate is naturally enhanced by
m_{3/2}/m_{\tilde{\nu}}={\cal O}(4\pi/\alpha) while the sneutrino decay rate is
small enough on a sizable portion of the parameter space. We point out also
that the sneutrino-antisneutrino mixing can provide much stronger information
on some combinations of the neutrino masses and mixing angles than neutrino
experiments.Comment: Revtex, 13 pages, 2 figure
Testing minimal lepton flavor violation with extra vector-like leptons at the LHC
Models of minimal lepton flavor violation where the seesaw scale is higher
than the relevant flavor scale predict that all lepton flavor violation is
proportional to the charged lepton Yukawa matrix. If extra vector-like leptons
are within the reach of the LHC, it will be possible to test the resulting
predictions in ATLAS/CMS.Comment: 19 pages, 8 figure
Organization of Multinational Activities and Ownership Structure
We develop a model in which multinational investors decide about the modes of organization, the locations of production, and the markets to be served. Foreign investments are driven by market-seeking and cost-reducing motives. We further assume that investors face costs of control that vary among sectors and increase in distance. The results show that (i) production intensive sectors are more likely to operate a foreign business independent of the investment motive, (ii) that distance may have a non-monotonous effect on the likelihood of horizontal investments, and (iii) that globalization, if understood as reducing distance, leads to more integration
A Private Underworld: The Naked Body in Law and Society
In general, the literature on privacy stresses, quite naturally, our right to keep things private, or to make our own decisions. The individual, the citizen, is the center of gravity. There is a great deal of material on the limits of privacy, on threats to privacy, and the like. In this Article, the authors want to discuss what one might call mandatory privacy: those aspects of life that we are required to keep secret, hidden, or private, the things that we must keep private, whether we want to or not. This is a subject that has been mostly, though not entirely, ignored in the privacy literature.
The authors conclude that there is no longer an ironclad rule that the body, or at least the private parts, have to remain that way: private. It has become a matter of choice. Forced bodily privacy has declined; now it is much more a matter for each person to decide, although there are still strong rules about behavior that seems threatening, abusive or pathological
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