10,272 research outputs found

    Structure of even-even nuclei using a mapped collective Hamiltonian and the D1S Gogny interaction

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    A systematic study of low energy nuclear structure at normal deformation is carried out using the Hartree-Fock-Bogoliubov theory extended by the Generator Coordinate Method and mapped onto a 5-dimensional collective quadrupole Hamiltonian. Results obtained with the Gogny D1S interaction are presented from dripline to dripline for even-even nuclei with proton numbers Z=10 to Z=110 and neutron numbers N less than 200. The properties calculated for the ground states are their charge radii, 2-particle separation energies, correlation energies, and the intrinsic quadrupole shape parameters. For the excited spectroscopy, the observables calculated are the excitation energies and quadrupole as well as monopole transition matrix elements. We examine in this work the yrast levels up to J=6, the lowest excited 0^+ states, and the two next yrare 2^+ states. The theory is applicable to more than 90% of the nuclei which have tabulated measurements. The data set of the calculated properties of 1712 even-even nuclei, including spectroscopic properties for 1693 of them, are provided in CEA website and EPAPS repository with this article \cite{epaps}.Comment: 51 pages with 26 Figures and 4 internal tables; this version is accepted by Physical Review

    Optimized Two-Baseline Beta-Beam Experiment

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    We propose a realistic Beta-Beam experiment with four source ions and two baselines for the best possible sensitivity to theta_{13}, CP violation and mass hierarchy. Neutrinos from 18Ne and 6He with Lorentz boost gamma=350 are detected in a 500 kton water Cerenkov detector at a distance L=650 km (first oscillation peak) from the source. Neutrinos from 8B and 8Li are detected in a 50 kton magnetized iron detector at a distance L=7000 km (magic baseline) from the source. Since the decay ring requires a tilt angle of 34.5 degrees to send the beam to the magic baseline, the far end of the ring has a maximum depth of d=2132 m for magnetic field strength of 8.3 T, if one demands that the fraction of ions that decay along the straight sections of the racetrack geometry decay ring (called livetime) is 0.3. We alleviate this problem by proposing to trade reduction of the livetime of the decay ring with the increase in the boost factor of the ions, such that the number of events at the detector remains almost the same. This allows to substantially reduce the maximum depth of the decay ring at the far end, without significantly compromising the sensitivity of the experiment to the oscillation parameters. We take 8B and 8Li with gamma=390 and 656 respectively, as these are the largest possible boost factors possible with the envisaged upgrades of the SPS at CERN. This allows us to reduce d of the decay ring by a factor of 1.7 for 8.3 T magnetic field. Increase of magnetic field to 15 T would further reduce d to 738 m only. We study the sensitivity reach of this two baseline two storage ring Beta-Beam experiment, and compare it with the corresponding reach of the other proposed facilities.Comment: 17 pages, 3 eps figures. Minor changes, matches version accepted in JHE

    Personal outcome measures and postal surveys of social care

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    Qualitative conditions of scientometrics: the new challenges'

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    While scientometrics is now an established field, there are challenges. A closer look at how scientometricians aggregate building blocks into artfully made products, and point-represent these (e.g. as the map of field X) allows one to overcome the dependence on judgements of scientists for validation, and replace or complement these with intrinsic validation, based on quality checks of the several steps. Such quality checks require qualitative analysis of the domains being studied. Qualitative analysis is also necessary when noninstitutionalized domains and/or domains which do not emphasize texts are to be studied. A further challenge is to reflect on the effects of scientometrics on the development of science; indicators could lead to `induced¿ aggregation. The availability of scientometric tools and insights might allow scientists and science to become more reflexive

    “Efficiency Flooding”: Black-Box Frontiers and Policy Implications

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    This research aims to comtribute to the discussion on the importance of theoretically consistent modelling for stochastic efficiency analysis. The robustness of policy suggestions based on inferences from efficiency measures crucially depends on theoretically well-founded estimates. The theoretical consistency of recently published technical efficiency estimates for different sectors and countries is critically reviewed. The results confirm the need for a posteriori checking the regularity of the estimated frontier by the researcher and, if necessary, the a priori imposition of the theoretical requirements.Efficiency Analysis, Functional Form, Mathematical Modelling

    An Update on the Science of Acidification in the Adirondack Park

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    This paper provides a review of the science pertaining to all aspects of acidification in the Adirondack Park, updating an earlier review of the science (Cook et al. 2002). The review supports an ongoing social science investigation into the willingness to pay for ecological improvements that would result from reduced acid deposition. This paper builds a bridge between the physical science and social science by providing the background that will allow researchers to accurately summarize the crucial elements of ecological status and improvement in a stated preference survey.acid rain, acidification, stated preference, willingness to pay, benefit estimation

    South Africa’s economics of education: A stocktaking and an agenda for the way forward

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    The paper reviews some of the existing economics of education literature from the perspective of South Africa’s education policymaking needs. It also puts forward a suggested research agenda for future work. The review is arranged according to five key areas of analysis: rates of return, production functions, teacher incentives, benefit incidence, cross-country comparisons. Whilst benefit incidence analysis is able to demonstrate large improvements in the equity of public financing, cross-county comparisons reveal that not only is quality inequitably distributed, it is overall well below what the country’s level of development would predict. Production functions, especially if translated to cost effectiveness models, can point to important policy solutions. Rates of return are difficult for policymakers to interpret, and need to be viewed in the context of qualifications. Teacher incentives is a policy area that is badly in need of a better theoretical and empirical basis.Economics of education, South Africa, education policy, rates of return, production functions, teacher incentives, benefit-incidence analysis
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