Embedding

To accurately assess the influence of the high track density environment of a heavy ion collision on the track reconstruction, simulated data from MTSIM can be superimposed onto an real experimentally measured event. In this case, the number of simulated tracks in each event must comprise a small fraction of the number of tracks in the experimental event, so that the event characteritics is not modified too strongly.

GTEMBED is the program that embeds the simulated data from MTSIM into experimental raw data. Track embedding is the process of adding together ADC signals in each pad-timeslice pixel from both data sets. The maximum possible signal of 255 ADC counts is imposed on the combined data and then the embedded event is compressed. A shortcoming of this method is that the 5 ADC count threshold of the data aquisition system had already been imposed upon both the simulated and experimental data before the embedding process occurs. As a result, the edges of some simulated charge clusters may be slightly cropped.

For simulating full event generator events, GTEMBED can also be run in a mode which does no embedding but only implements the simulation of the electronics saturation.

Below you can see two scripts: one for reconstruction without embedding, and the last one with embedding.

Script to run reconstruction without embedding

Script to run reconstruction with embedding