Several scientific fields, including Astrophysics, Astroparticle Physics, Cosmology, Nuclear and Particle Physics, and Research with Photons, are estimating that by the 2020 decade they will require ...data handling systems with data volumes approaching the Zettabyte distributed amongst as many as 1018 individually addressable data objects (Zettabyte-Exascale systems). It may be convenient or necessary to deploy such systems using multiple physical sites. This paper describes the findings of a working group composed of experts from several
The BaBar experiment's computing resources are geographically spread out. A direct consequence of this is that a large amount of data is transferred between sites. Providing easy management and ...access to these data is a challenging task. To accomplish this task we are employing the storage resource broker (SRB), developed at the San Diego Super Computing Center, to manage the BaBar data files and to replicate them between Tier-A centers. The system has been tested between the computing centers l'Institut National de Physique Nucle/spl acute/aire et de Physique des Particules (CC-IN2P3), Lyon, France, and at Stanford Linear Accelerator Center (SLAC), Menlo Park, CA, and this paper discusses our experience with a view to production use. We describe how the system could be used to manage the data import/export between the computing sites and how it fits into building a BaBar data grid. We also explain how a user benefits from this system to access and obtain data in an easy and transparent fashion.
Policy-oriented data management is an emerging field that provides automation of large collection management using policies encoded as machine-executable rules. Digital archives provide long term ...preservation of collections that can span decades across multiple technology refreshes. Policy-based data management is critical for digital archives because of the need to maintain integrity across long spans of time. The management of preservation policies for large collections can be an onerous task. Typical policies may control ingest of records, extraction of required provenance information, replication of records, retention and disposition, and validation of assessment criteria. The iRODS (the integrated Rule-Oriented Data System) is an exemplar that provides distributed data management under a policy-oriented framework that can be applied to long-term data archiving. We will present a demonstration of the preservation environment, including the composition of preservation policies and automated enforcement of policies. A user interface framework will be demonstrated that manages ingest of records into a staging area, automates application of preservation policies, and tracks status of the processing steps.
Data collected at centre-of-mass energies of 181-184 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 56.9 pb^-1, are analysed in a search for pair-produced charged Higgs bosons H+-. ...Three analyses are employed to select the tau nu tau nu, tau nu c s and c s c s final states. No evidence for a signal is found. Mass limits are set as a function of the branching fraction B( H+ -> tau+ nu ). Under the assumption that the decay modes considered cover the totality of the possible final states, charged Higgs bosons with masses below 59 GeV/c^2 are excluded at 95% C.L. independently of B( H+ -> tau+ nu ).
A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQDbar coupling has been performed using the data collected by ALEPH at ...centre-of-mass energies of 130-172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m_0=500 GeV/c^2 and tan(beta)=sqrt(2) charginos with masses smaller than 81 GeV/c^2 and neutralinos with masses smaller than 29 GeV/c^2 are excluded at the 95% confidence level for any generation structure of the LQDbar coupling.
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