Speakers
Dr
Donatella Lucchesi
(INFN Padova)Dr
Francesco Delli Paoli
(INFN Padova)
Description
The CDF experiment has a new trigger which selects events depending on the
significance of the track impact parameters. With this trigger a sample of events
enriched of b and c mesons has been selected and it is used for several important
physics analysis like the Bs mixing. The size of the dataset is of about 20 TBytes
corresponding to an integrated luminosity of 1 fb-1 collected by CDF. CDF has
developed a skimming procedure to reduce the dataset by selecting events which
contain only B mesons in specifics decay modes. The rejected events are almost
background, and this guarantees that no signal is lost while the processing time is
reduced by factor 10. This procedure is based on SAM (Sequential Access via
Metadata), the CDF data handling system. Each file from the original dataset is read
via SAM and processed on the CDF users farm at Fermilab. The outputs are stored and
cataloged via SAM on a temporary disk location at Fermilab in order to be finally
concatenated. This final step consists of copy and then store and catalog the output
in Italy on disks hosted at Tier 1, permanently. These skimmed data are available in
Italy for the CDF collaboration, and user can access them via the Italian CDF farm.
We will describe the procedure to skim data, concatenate the output and the method
used to control that each input file is processed once and only once. The tool to
copy data from the users farm to temporary and permanent disk locations, developed
by CDF,consists of users authentication plus a transfer layer. Users allowed to
perform the copy are mapped in a gridmap file and authenticated with a Globus
Security Infrastructure (GSI). Details on the tool performances and the use and the
definition of a remote permanent disk location will be described in detail.
Primary author
Dr
Donatella Lucchesi
(INFN Padova)
Co-authors
Dr
Armando Fella
(INFN Pisa)
Dr
Francesco Delli Paoli
(INFN Padova)
Dr
Massimo Casarsa
(INFN Trieste)
Dr
Saverio Da Ronco
(INFN Padova)
