81 research outputs found
GridCertLib: a Single Sign-on Solution for Grid Web Applications and Portals
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
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
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 Annihilations
I present preliminary results on the search for in its
and decay modes. We observe an excess of \eta_c\gamma{\cal P} \sim 0.001M=3525.8 \pm 0.2 \pm 0.2
\Gamma\leq10.6\pm 3.7\pm3.4(br) <
\Gamma_{\bar{p}p}B_{\eta_c\gamma} < 12.8\pm 4.8\pm4.5(br) 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
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
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 and States of Charmonium formed in Antiproton-Proton Annihilations
We have studied the ( 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 for the
and by means of the inclusive reaction . Using the subsample of
events where is
fully reconstructed, we derive . We summarize the results of the E760
(updated) and E835 measurements of mass, width and (J=0,1,2) and discuss the significance of
these measurements
Housing metadata for the common physicist using a relational database
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 two photon decay of the Ïc0(13P0) state of charmonium
AbstractWe report on the decay to two photons of the Ïc0(13P0) charmonium resonance formed in pÌp interactions at Fermilab experiment E835. We have measured the product of branching ratios BR(Ïc0âpÌp)ĂBR(Ïc0âγγ)=(6.52±1.18(stat)+0.48â0.72(sys))Ă10â8. Using values from the 2002 PDG, this measurement leads to the partial width Î(Ïc0âγγ)=2.9±0.9 keV
Measurement of the branching ratios , and
We have measured several branching ratios for decay using the
data collected by FNAL E835 experiment during year 2000, obtaining , , and . We also present a measurement of the
dipion mass distribution in the decays
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