Tasks and Responsibilities of the Data Preparation area

This area is in charge of the the first three steps of analysis after the data arrive at the Tier0, and of the corresponding aspects for the simulated events:

1) Offline data quality and data treatment

2) Reconstruction, calibration and alignment at the (sub-)detector level, that is up to clusters in the individual calorimeters and tracks in the Inner Detector and Muon Spectrometer separately. This is performed for both the real data and the simulated data.

3) First combined reconstruction of physics objects (electrons, muons, jets, etc.) by putting together the information of various sub-detectors, and use of these objects to align and calibrate the various sub-detectors. These studies are made with both the real data and the simulated data. Here “first reconstruction” indicates that the target is to understand the detector performance rather than to optimize the algorithms for their use in different physics channels (the latter is a task of the Combined Performance WGs).

4) Improvement and maintenance of the sub-detector G4-simulations, in particular injecting more realism based on information from the data (simulation of electronic noise, cross-talk, dead regions, of the response variation with time, etc.).

Point 3) and other general tasks of the Data Preparation area are described here

Points 1), 2) and 4) above are the tasks and responsibilities of the (sub-)systems and are described below

Examples of aspects to be covered in Point 1) are:

• development of algorithms and procedures to spot and correct detector problems, like noisy channels, dead regions, HV problems, etc.
• application of these algorithms and procedures to the data
• calibration of the detector response at the readout channel (e.g. calorimeter cell) level using the results of the hardware calibration systems (e.g. pedestals, test pulses) as well as software techniques (e.g. optimal filtering)

Examples of aspects to be covered in Point 2) are:

• maintain and improve algorithms for the reconstruction up to clusters in the individual calorimeters and up to track segments in the two tracking systems
• align the Inner Detector and Muon Spectrometer using track segments and fully reconstructed global tracks in each system
• apply the needed corrections to the clusters (e.g. containment) and perform first calibration (e.g. corrections for upstream material)

The sub-system activities described above have two reporting lines:

-- the Computing area, for the technical coordination of the Software developments and their integration into the overall ATLAS Software system (more here).

-- the Data Preparation area, for the overall coordination and strategy (more here).

-- FabiolaGianotti - 21 Sep 2005