Data Quality Management

1. Calibrations ProductionExe Beam Lines Data Quality Management (DQM) for the CDF Experiment IFAE-CDF group has taken major responsibilities on data quality control of the physics data collected by the experiment. This implies the design and construction of 'online' and 'offline' DQM expert systems. They will allow IFAE to perform a real-time 'online' control check of the data being collected, as well as to validate the 'offline' reconstruction of high-level objects used in physics analyzes. Official lists of 'good runs' are provided based on DQM decisions on data quality. ONLINE OFFLINE During data taking ... After data is reprocessed… The DQMOnline system uses histograms produced by ConsumerMonitors to make a complete diagnostic, in real-time, of the detector’s status. It monitors the basic performance of the different sub-systems (occupancies, high-voltages, dead/hot channels,etc..) It also identifies possible problems inside a run, and marks the affected run-sections differently, in order to ignore them in the physics analyses. The DQMOffline system uses histograms produced during the offline reprocessing (Production+Validation) of the data, where the latest calibration and alignment constants are used to reconstruct high-level objects (electrons,. Photons, jets, J/Y , etc..) employed in physics analyses. A number of critical quantities are selected, enough to provide a complete characterization of the quality of the data. Detectors HV Status CSL ValidationExe (Streams A/B/C) Online Consumer Monitors (L3 Objects, % events) DQM Online Run Summary DQM Critical Histograms RC YMon ……. PhysMon XMon TrigMon SPL’s Alarm!! CO DQM Offline (expert system) Alarm!! SciCo ACEs DQM Online (expert system) WWW Regular reports DataBase Online Good Run GUI CDF Collaboration DQM Responsible on call DataBase DQM bits • Online Consumers produce histograms (from a limited sample of events) which provide information about the status of the different sub-detectors. • The DQM Online expert system analyzes those histograms and flags any possible error detected. • The DQM Online monitor (running inside the CDF control room) displays the status of online consumers and detectors, as well as beam conditions. • Colors indicate: error (red), warning (yellow), ok (green) and no decision (cyan). • User is able to disable or enable different sub-detectors. • An error log is kept for each run and it is available via the WWW. • A voice alarm is triggered to alert the shift crew of any problems. • The online monitor GUI determines the Online Good Run Bits and writes them into the online database. • DQM Online decisions are monitored daily and validated by DQM representatives. • Fundamental quantities and high-level physics objects are reconstructed taking into account the latest calibration constants and beam lines reconstructed offline. • The expert system implements the logic to automatically analyze the critical histograms and evaluate the quality of the data. The DQM Online decision is also used as an input. • The errors detected (either due to raw detector quantities or caused by offline reconstruction codes) are promptly reported to detector experts (SPL’s). • The final DQM results are translated into a set of bits and collected on databases. In addition, complete documentation is provided via Web pages and regular reports to CDF. • Lists of Good Runs are defined using the DQM decisions, that are combined according to different quality requirements as established within each physics group. Look for empty channels J/ Reconstructed Mass The position and the width of the reconstructed J/Y mass peak, and the relative size of signal and background (sideband) regions, are sensitive to the global performance of the CDF tracking system , as well as to the algorithms for track reconstruction, calibration constants and beam-line position. GUI to update problematic channels A GUI interface (to be used by detector experts) keeps a reference database of good and bad channels and allows the DQM expert system to identify ‘already-known’ problems