674 research outputs found

    OGSA/Globus Evaluation for Data Intensive Applications

    Full text link
    We present an architecture of Globus Toolkit 3 based testbed intended for evaluation of applicability of the Open Grid Service Architecture (OGSA) for Data Intensive Applications.Comment: To be published in the proceedings of the XIX International Symposium on Nuclear Electronics and Computing (NEC'2003), Bulgaria, Varna, 15-20 September, 200

    Revisiting the 'Missing Middle' in English Sub-National Governance

    Get PDF
    In the light of the new Coalition Government’s proposed ‘rescaling’ of sub-national governance away from the regional level, it is an opportune time to re-consider the strength and weaknesses of the city or sub-regional approach to economic development and to search, once more, for the ‘missing middle’ in English Governance. In this context, the article initially assesses the case for city or sub regions as tiers of economic governance, before examining the lessons to be learnt from the experiences of the existing city regions in the North East of England. It argues that while contemporary plans to develop Local Enterprise Partnerships (LEPs) can be usefully considered within the context of the emerging city regional developments under the previous Labour Governments, a number of important challenges remain, particularly in relation to ensuring accountable structures of governance, a range of appropriate functions, adequate funding, and comprehensive coverage across a variety of sub-regional contexts. While the proposals of the new Government create the necessary ‘space’ to develop sub-regional bodies and offer genuine opportunities for both city and county LEPs, the scale of the sub-regional challenge should not be underestimated, particularly given the context of economic recession and major reductions in the public sector

    Open and Hidden Charm Production in 920 GeV Proton-Nucleus Collisions

    Full text link
    The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B spectrometer covers negative values of xF up to xF=-0.3 and a broad range in transverse momentum from 0.0 to 4.8 GeV/c. The studies presented in this paper include J/psi differential distributions and the suppression of J/psi production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.Comment: 5 pages, 9 figures, to be published in the proceedings of the 6th International Conference on Hyperons, Charm & Beauty Hadrons (BEACH04), Chicago, IL, June 27 - July 3, 200

    The Outer Tracker Detector of the HERA-B Experiment Part I: Detector

    Full text link
    The HERA-B Outer Tracker is a large system of planar drift chambers with about 113000 read-out channels. Its inner part has been designed to be exposed to a particle flux of up to 2.10^5 cm^-2 s^-1, thus coping with conditions similar to those expected for future hadron collider experiments. 13 superlayers, each consisting of two individual chambers, have been assembled and installed in the experiment. The stereo layers inside each chamber are composed of honeycomb drift tube modules with 5 and 10 mm diameter cells. Chamber aging is prevented by coating the cathode foils with thin layers of copper and gold, together with a proper drift gas choice. Longitudinal wire segmentation is used to limit the occupancy in the most irradiated detector regions to about 20 %. The production of 978 modules was distributed among six different laboratories and took 15 months. For all materials in the fiducial region of the detector good compromises of stability versus thickness were found. A closed-loop gas system supplies the Ar/CF4/CO2 gas mixture to all chambers. The successful operation of the HERA-B Outer Tracker shows that a large tracker can be efficiently built and safely operated under huge radiation load at a hadron collider.Comment: 28 pages, 14 figure

    Aging Studies for the Large Honeycomb Drift Tube System of the Outer Tracker of HERA-B

    Full text link
    The HERA-B Outer Tracker consists of drift tubes folded from polycarbonate foil and is operated with Ar/CF4/CO2 as drift gas. The detector has to stand radiation levels which are similar to LHC conditions. The first prototypes exposed to radiation in HERA-B suffered severe radiation damage due to the development of self-sustaining currents (Malter effect). In a subsequent extended R&D program major changes to the original concept for the drift tubes (surface conductivity, drift gas, production materials) have been developed and validated for use in harsh radiation environments. In the test program various aging effects (like Malter currents, gain loss due to anode aging and etching of the anode gold surface) have been observed and cures by tuning of operation parameters have been developed.Comment: 14 pages, 6 figures, to be published in the Proceedings of the International Workshop On Aging Phenomena In Gaseous Detectors, 2-5 Oct 2001, Hamburg, German

    Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic Muon-Proton Scattering

    Get PDF
    We have measured the spin-dependent structure function g1pg_1^p in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range 0.003<x<0.70.003 < x < 0.7 and 1GeV2<Q2<60GeV21 GeV^2 < Q^2 < 60 GeV^2. A next-to-leading order QCD analysis is used to evolve the measured g1p(x,Q2)g_1^p(x,Q^2) to a fixed Q02Q^2_0. The first moment of g1pg_1^p at Q02=10GeV2Q^2_0 = 10 GeV^2 is Γp=0.136±0.013(stat.)±0.009(syst.)±0.005(evol.)\Gamma^p = 0.136\pm 0.013(stat.) \pm 0.009(syst.)\pm 0.005(evol.). This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge a0a_0 is found to be 0.28±0.160.28 \pm 0.16. In the Adler-Bardeen factorization scheme, Δg2\Delta g \simeq 2 is required to bring ΔΣ\Delta \Sigma in agreement with the Quark-Parton Model. A combined analysis of all available proton and deuteron data confirms the Bjorken sum rule.Comment: 33 pages, 22 figures, uses ReVTex and smc.sty. submitted to Physical Review

    Inclusive V0V^0 Production Cross Sections from 920 GeV Fixed Target Proton-Nucleus Collisions

    Full text link
    Inclusive differential cross sections dσpA/dxFd\sigma_{pA}/dx_F and dσpA/dpt2d\sigma_{pA}/dp_t^2 for the production of \kzeros, \lambdazero, and \antilambda particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to s=41.6\sqrt {s} = 41.6 GeV in the proton-nucleon system. The ratios of differential cross sections \rklpa and \rllpa are measured to be 6.2±0.56.2\pm 0.5 and 0.66±0.070.66\pm 0.07, respectively, for \xf 0.06\approx-0.06. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions dσpA/dpt2d\sigma_{pA}/dp_t^2 also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections σpA\sigma_{pA} on the atomic mass AA of the target material is discussed, and the deduced cross sections per nucleon σpN\sigma_{pN} are compared with results obtained at other energies.Comment: 17 pages, 7 figures, 5 table

    Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries

    Get PDF
    We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0.0030.0031 GeV2^2. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at Q2Q^2=10 GeV2^2. The polarised uu valence quark distribution, Δuv(x)\Delta u_v(x), is positive and the polarisation increases with xx. The polarised dd valence quark distribution, Δdv(x)\Delta d_v(x), is negative and the non-strange sea distribution, Δqˉ(x)\Delta \bar q(x), is consistent with zero over the measured range of xx. We find for the first moments 01Δuv(x)dx=0.77±0.10±0.08\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08, 01Δdv(x)dx=0.52±0.14±0.09\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09 and 01Δqˉ(x)dx=0.01±0.04±0.03\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03, where we assumed Δuˉ(x)=Δdˉ(x)\Delta \bar u(x) = \Delta \bar d(x). We also determine for the first time the second moments of the valence distributions 01xΔqv(x)dx\int_0^1 x \Delta q_v(x) dx.Comment: 17 page

    Distributive politics and regional development: assessing the territorial distribution of Turkey’s public investment

    Get PDF
    Turkey is often perceived as a country with low bureaucratic capacity and prone to political manipulation and ‘pork-barrel’. This article tests whether this is the case, by analysing the extent to which politics, rather than equity and efficiency criteria, have determined the geographical allocation of public investment across the 81 provinces of Turkey between 2005 and 2012. The results show that although the Turkish government has indeed channelled public expenditures to reward its core constituencies, socioeconomic factors remained the most relevant predictors of investment. Moreover, in contrast to official regional development policy principles, we uncover the concentration of public investment in areas with comparatively higher levels of development. We interpret this as the state bureaucracy’s intentional strategy of focussing on efficiency by concentrating resources on ‘the better off among the most in need’

    Integración a la vida universitaria: ingreso a las carreras de la facultad de ingeniería

    Get PDF
    El diseño de este curso surgió de los aportes que fueron volcando, en sucesivos encuentros, docentes de los departamentos de ciencias básicas (matemática, física y química), docentes del ciclo de orientación de cada una de las ingenierías, personal de la administración de la facultad y el centro de estudiantes. Cada actor institucional, desde la experiencia y el lugar que ocupa en el proceso de enseñanza-aprendizaje, fue aportando su visión y sus ideas para mejorar las condiciones en las que recibimos a los alumnos ingresantes.Fil: Posse, Susana. Universidad Nacional del Comahue. Facultad de Ingeniería; Argentina
    corecore