Modifications in Gaudi v5 release: Access to SICB data Modifications in Gaudi v5 release: Pile up. Other new features: Pre-staging of several tapes Access to new data base Gonzalo Gracia Abril

Pile Up Implementation Pile up infra-structure was already in Gaudi v4 But it uses internally SICB and it was not working. Some more debugging was required. Pile up is implemented as a separate algorithm which has to run before any other algorithm which access data: JobOptions: ApplicationMgr.TopAlg = { "PileUpAlg",”myAlg1",”myAlg2" }; Number of pile up events is calculated as a function of the luminosity. RELUMI re-implemented in C++: Reads beam.cdf file to get input parameters. Uses new random generator service (See later) Two files read in, one for the main event and the second for pile up events.

SicbEventSelector ApplicationMgr taSvc icnbSicbPileupAlg ReMerge SICB IProperty IProperty “ EventSetector ” SicbEventSelector IEventSelector SicbEventSelector IEventSelector ApplicationMgr ApplicationMgr IDataManagerService IDataManagerSvc ZEBRA “ EventDataSvc ” taSvc EventDataSvc “ PileupAlg ” icnbSicbPileupAlg SicbPileUpAlg IDataProviderSvc ReMerge IDataProviderSvc SICB specific IDataProviderSvc “ PileupSvc ” SicbPileupSvc “ PileupDataSvc ” EventDataSvc SicbPileUpSvc EventDataSvcvc ZEBRA IDataManagerService IDataManagerSvc “ PileupSelector ” SicbEventSelector IEventSelector SicbEventSelector The Algorithm and Service are merged into one Algorithm for the Sicb version Not needed for the SICB version IEventSelector The Algorithm and Not needed for Service are merged the Sicb version IProperty into one Algorithm for IProperty the Sibc version

Random Numbers Reminder : Two random numbers are generated for every event to get the number of pile up events: First number generated following a flat distribution (0,1) to calculate the current luminosity (from the fill duration and beam decay time, the current time in the fill is the random number). Second (number of interactions): Follows a Poisson distribution whose mean is equal to the average number of interactions for the current luminosity (extracted from the cross section and the bunch crossing rate) If the number of iterations is 0 we repeat the process until is different than 0 Random number service is now available in Gaudi and we have chosen to use it.

Number of interactions. Histogram: Gaudi Points: SICBDST 500 Events Number of interactions.

Average number of interactions per bunch crossing. Histogram: Gaudi Points: SICBDST 500 Events Average number of interactions per bunch crossing.

Pile Up: Some comments The actual merging of events is done by REMERGE ATMC, AVMC and raw hits banks are merged. (CALO raw banks are not converted) When you retrieve, from your Gaudi Algorithm, data converted from one of these banks you will get the merged data. In the conversion Gaudi follows every reference, we find always the missing or wrong references!!. (It runs in 500 events, several data samples tried… but watch the DST2 problems!!) Two instances of the event selector which are configured separately

Other new features Pre-staging of several tapes: You wait for the first tape. The others are staged while you read the first one. If you finish reading the first file and the second tape is not staged you will get a message and will have to wait. Access to tapes is not possible from NT Access to new data base Gaudi sends a request to the ORACLE web server Executes the same procedure used by mcstagein to get the volume number, file sequence number and size.