81 research outputs found

    GridCertLib: a Single Sign-on Solution for Grid Web Applications and Portals

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    This paper describes the design and implementation of GridCertLib, a Java library leveraging a Shibboleth-based authentication infrastructure and the SLCS online certificate signing service, to provide short-lived X.509 certificates and Grid proxies. The main use case envisioned for GridCertLib, is to provide seamless and secure access to Grid/X.509 certificates and proxies in web applications and portals: when a user logs in to the portal using Shibboleth authentication, GridCertLib can automatically obtain a Grid/X.509 certificate from the SLCS service and generate a VOMS proxy from it. We give an overview of the architecture of GridCertLib and briefly describe its programming model. Its application to some deployment scenarios is outlined, as well as a report on practical experience integrating GridCertLib into portals for Bioinformatics and Computational Chemistry applications, based on the popular P-GRADE and Django softwares.Comment: 18 pages, 1 figure; final manuscript accepted for publication by the "Journal of Grid Computing

    Adapting SAM for CDF

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    The CDF and D0 experiments probe the high-energy frontier and as they do so have accumulated hundreds of Terabytes of data on the way to petabytes of data over the next two years. The experiments have made a commitment to use the developing Grid based on the SAM system to handle these data. The D0 SAM has been extended for use in CDF as common patterns of design emerged to meet the similar requirements of these experiments. The process by which the merger was achieved is explained with particular emphasis on lessons learned concerning the database design patterns plus realization of the use cases.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, pdf format, TUAT00

    Precision measurements of the total and partial widths of the psi(2S) charmonium meson with a new complementary-scan technique in antiproton-proton annihilations

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    We present new precision measurements of the psi(2S) total and partial widths from excitation curves obtained in antiproton-proton annihilations by Fermilab experiment E835 at the Antiproton Accumulator in the year 2000. A new technique of complementary scans was developed to study narrow resonances with stochastically cooled antiproton beams. The technique relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. We study the psi(2S) meson through the processes pbar p -> e+ e- and pbar p -> J/psi + X -> e+ e- + X. We measure the width to be Gamma = 290 +- 25(sta) +- 4(sys) keV and the combination of partial widths Gamma_e+e- * Gamma_pbarp / Gamma = 579 +- 38(sta) +- 36(sys) meV, which represent the most precise measurements to date.Comment: 17 pages, 3 figures, 3 tables. Final manuscript accepted for publication in Phys. Lett. B. Parts of the text slightly expanded or rearranged; results are unchange

    E835 at FNAL: Charmonium Spectroscopy in pˉp\bar p p Annihilations

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    I present preliminary results on the search for hch_c in its ηcÎł\eta_c\gamma and J/ψπ0J/\psi\pi^0 decay modes. We observe an excess of \eta_c\gammaeventsnear3526MeVthathasaprobability events near 3526 MeV that has a probability {\cal P} \sim 0.001toarisefrombackgroundfluctations.Theresonanceparametersare to arise from background fluctations. The resonance parameters are M=3525.8 \pm 0.2 \pm 0.2 MeV,MeV, \Gamma\leq1MeV,and 1 MeV, and 10.6\pm 3.7\pm3.4(br) < \Gamma_{\bar{p}p}B_{\eta_c\gamma} < 12.8\pm 4.8\pm4.5(br) eV.WefindnoeventexcesswithinthesearchregionintheeV. We find no event excess within the search region in the J/\psi\pi^0$ mode.Comment: Presented at the 6th International Conference on Hyperons, Charm and Beauty Hadrons (BEACH 2004), Chicago(Il), June 27-July 3,200

    Interference Study of the chi_c0 (1^3P_0) in the Reaction Proton-Antiproton -> pi^0 pi^0

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    Fermilab experiment E835 has observed proton-antiproton annihilation production of the charmonium state chi_c0 and its subsequent decay into pi^0 pi^0. Although the resonant amplitude is an order of magnitude smaller than that of the non-resonant continuum production of pi^0 pi^0, an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. The amplitudes J=0 and 2, of comparable strength, dominate the expansion. Both are accessed by L=1 in the entrance proton-antiproton channel. The product of the input and output branching fractions is determined to be B(pbar p -> chi_c0) x B(chi_c0 -> pi^0 pi^0)= (5.09 +- 0.81 +- 0.25) x 10^-7.Comment: 4 pages, 4 figures, Accepted by PRL (July 2003

    A Study of \bar{p}p -> Two Neutral Pseudoscalar Mesons at the chi_c0(1^3P_0) Formation Energy

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    Fermilab experiment E835 has studied reactions \bar{p}p -> pi0 pi0, pi0 eta, eta eta, pi0 eta' and eta eta' in the energy region of the chi_c0(1^3P_0) from 3340 MeV to 3470 MeV. Interference between resonant and continuum production is observed in the pi0 pi0 and eta eta channels, and the product of the input and output branching fractions is measured. Limits on resonant production are set for the pi0 eta and pi0 eta' channels. An indication of interference is observed in the eta eta' channel. The technique for extracting resonance parameters in an environment dominated by continuum production is described.Comment: 15 pages, 21 figures, submitted Phys. Rev.

    Measurement of the Resonance Parameters of the χ1(13P1)\chi_{1}(1^3P_1) and χ2(13P2)\chi_{2}(1^3P_2) States of Charmonium formed in Antiproton-Proton Annihilations

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    We have studied the 3PJ^3P_J (χc)\chi_c) states of charmonium in formation by antiproton-proton annihilations in experiment E835 at the Fermilab Antiproton Source. We report new measurements of the mass, width, and B(χcJ→pˉp)×Γ(χcJ→J/ψ+anything)B(\chi_{cJ} \to \bar{p} p) \times \Gamma(\chi_{cJ} \to J/\psi + anything) for the χc1\chi_{c1} and χc2\chi_{c2} by means of the inclusive reaction pˉp→χcJ→J/ψ+anything→(e+e−)+anything\bar{p}p \to \chi_{cJ} \to J/\psi + anything \to (e^{+}e^{-}) +anything . Using the subsample of events where χcJ→γ+J/Ïˆâ†’Îł+(e+e−)\chi_{cJ} \to \gamma + J/\psi \to \gamma + (e^{+}e^{-}) is fully reconstructed, we derive B(χcJ→pˉp)×Γ(χcJ→J/ψ+Îł)B(\chi_{cJ} \to \bar p p)\times \Gamma(\chi_{cJ} \to J/\psi + \gamma) . We summarize the results of the E760 (updated) and E835 measurements of mass, width and B(χcJ→pˉp)Γ(χcJ→J/ψ+Îł) B(\chi_{cJ} \to \bar{p}p) \Gamma(\chi_{cJ} \to J/\psi+\gamma) (J=0,1,2) and discuss the significance of these measurements

    Housing metadata for the common physicist using a relational database

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    SAM was developed as a data handling system for Run II at Fermilab. SAM is a collection of services, each described by metadata. The metadata are modeled on a relational database, and implemented in ORACLE. SAM, originally deployed in production for the D0 Run II experiment, has now been also deployed at CDF and is being commissioned at MINOS. This illustrates that the metadata decomposition of its services has a broader applicability than just one experiment. A joint working group on metadata with representatives from ATLAS, BaBar, CDF, CMS, D0, and LHCB in cooperation with EGEE has examined this metadata decomposition in the light of general HEP user requirements. Greater understanding of the required services of a performant data handling system has emerged from Run II experience. This experience is being merged with the understanding being developed in the course of LHC experience with data challenges and user case discussions. We describe the SAM schema and the commonalities of function and service support between this schema and proposals for the LHC experiments. We describe the support structure required for SAM schema updates, the use of development, integration, and production instances. We are also looking at the LHC proposals for the evolution of schema using keyword-value pairs that are then transformed into a normalized, performant database schema

    Measurement of the branching ratios ψâ€Č→e+e−\psi^\prime \to e^+ e^-, ψâ€Č→J/ψππ\psi^\prime \to J/\psi \pi \pi and ψâ€Č→J/ψη\psi^\prime \to J/\psi \eta

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    We have measured several branching ratios for ψâ€Č\psi^\prime decay using the data collected by FNAL E835 experiment during year 2000, obtaining B(ψâ€Č→e+e−)=0.0068±0.0001±0.0004{\cal B}(\psi^\prime \to e^+ e^-) = 0.0068\pm0.0001\pm0.0004, B(ψâ€Č→J/ψπ+π−)=0.292±0.005±0.018{\cal B}(\psi^\prime \to J/\psi \pi^+ \pi^-) = 0.292\pm0.005\pm0.018, B(ψâ€Č→J/ψπ0π0)=0.167±0.005±0.014{\cal B}(\psi^\prime \to J/\psi \pi^0 \pi^0) = 0.167\pm0.005\pm0.014 and B(ψâ€Č→J/ψη)=0.028±0.002±0.002{\cal B}(\psi^\prime \to J/\psi \eta) = 0.028\pm0.002\pm0.002. We also present a measurement of the dipion mass distribution in the decays ψâ€Č→J/ψππ\psi^\prime \to J/\psi \pi \pi
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