Glossary of data types

MonteCarlo truth.

Consists of:

MC Kinematics

The output of the event generator, before tracking through the detector (e.g. KINE+VERT banks), plus secondary tracks created in the detector via material interactions or decay in flight

MC Hits

Simulated hits resulting from tracking the kinematics particles through the active regions of the detector. This is the input to the digitisation step of the simulation.

Raw data

Can be real or simulated:

Real raw data is the data format at the output of the data acquisition system (e.g. ADC counts) and is the input to the higher level (software) triggers and the coordinate reconstruction.

Simulated raw data has identical format to the real raw data, with the addition of links to the MonteCarlo truth. It is produced in the digitisation step of the simulation by applying a detector response function.

Reconstructed coordinates

These are derived from the raw data by applying an apparatus function (such as a drift time-distance relation), using appropriate calibration and/or alignment constants. They are the input to the pattern recognition. They may be produced, with different levels of refinement, by the detector front ends, the software triggers or the reconstruction program. They contain links to the raw data.

In the simulation, they may in addition be produced directly from the MonteCarlo Truth. This can be the case in a fast MonteCarlo, where the digitisation step is skipped, but is forbidden in the complete detector simulation.

Reconstructed objects

This is the output of the reconstruction program and consists of physics quantities such as tracks and clusters, plus links to the coordinates.

Analysis objects

These are a different view of the reconstruction output, for use in the analysis. They may be a condensed form of the reconstruction objects (e.g. tracks defined only at the origin, with no reference to coordinates, but with some kind of association to the original MC Truth track) or a different abstraction (e.g. "tracks" could include also neutral calorimeter objects)