SSD in the dst tables and dst analysis Dst tables StEvent
Dst tables
At the end of the reconstruction chain, parts of the produced tables are saved into dst tables. Information from the SSD is stored in several dst tables :

The dst_monitor_soft_svt table contains SVT-SSD event reconstruction monitoring quantities which are used to determine the general quality of the event reconstruction production chain (BFC). It is filled with information for one event per table row. This table is intended for both simulations and experimental data. Several variables (number of clusters, number of space points...) of this table contain 4 columns where the fourth one is dedicated for the SSD. Saving of SSD information in this table still need to be done.

The dst_point table contains event reconstruction information about the space points generated by each tracking detector. It is filled with information for one event with one space point per table row. All space points are loaded and data packing is used for each variable except id_track. The current hw_position (32 bit variable) packing algorithm for the SSD is the following (and different from the one appearing in the dst_point.idl header) :

bits variable
0-3 detector ID number (8)
4-12num_wafer (0-319)
13-22central strip of the n-side cluster (1-768)
23-27strip of the p-side cluster relat. to n-side (-15,+16)
28-29n-side cluster size (1-4)
30-31p-side cluster size (1-4)
This packing scheme will changed once the num_wafer is removed and the available bits will be used to encode cluster matching quality factor. This table is filled by dst_point_filler.F from the pams/global/dst directory.

The dst_track table contains event reconstruction information about the charged particle tracks generated by each tracking detector which have been assigned the status of global tracks by global tracking analysis. It is filled with information for one event with one track per table row. Several variables contain information wether or not SSD hits have been used in the tracks : iflag, n_max_point,det_id,map,... Look at the top part of the table idl file for more details. One should note that the method variable contains information about the tracking algorithm and can indicate that the EST package has been used.

The StEvent package has been build in order to built an object oriented representation of the event loaded for example from the dst tables. Several classes and functions have been defined in order to store the SSD hits from the dst_point table. They are defined and described in the following files :


Last modified: Wed Jan 19 16:48:51 MET