This section describes the various event-data files that are used in the MuID offline software.
The raw-data files (also called PRDF files, referring to the PHENIX raw-data format) contain the packets from the data-collection modules (DCMs). When properly "unpacked" (as described in the section on the unpacking chain) the raw data from the DCM packets are placed in the dMuiRaw table. Note that this procedure holds for simulated raw data as well as real raw data.
The data-summary (DST) files contain the output of reconstruction. That is, some of the data that are produced in the reconstruction chain are saved to permit more refined analyses with the reconstructed track and particle information.
The primary MuID data that are saved to the DST are the dMuiRoads, dMuiClusters, and dMuiRoadClusterRel tables (not counting the dMuoTrackRoadRel table, which belongs more to the category of "global" muon data). The dMuiRoads table contains the data on the reconstructed roads, while the dMuiRoadClusterRel table shows which clusters each road contains, so that we can refer back to the dMuiClusters table to find out the space points used in each gap.
In addition, the dMuiClusterRawRel table is also saved to the DST at the current time, to allow the reconstructed roads and clusters to be traced back to their component raw hits. There should be no need to save the dMuiRaw data, assuming that the DST contains the identity of the raw event that produced each DST event; we can then retrieve the appropriate data directly from the raw data (PRDF) file.
It may be useful to save the parameter data (e.g., the "control" tables for the road and cluster finders) to the DST as well, for the purpose of documenting the conditions under which the data were reconstructed. The various parameter tables are being kept (instead of being integrated with the relevant modules) to allow this to be done, if people decide that it is useful. However, these data are not saved at the current time.
When running simulations, there are two additional types of files that are directly relevant to MuID, the PISA file and the evaluation (or "raw-relational") file.
The PISA file contains the output of the GEANT simulation of the trajectories of particles passing through the detector volumes, with its primary output in the form of hits and tracks. The GEANT hit data for MuID are contained in the munhits table. The parameters of the tracks are found in the fkin table; this information is primarily accessed through the ptrkorigin and ptrkstack utilities provided by the Vanderbilt group.
The evaluation file is intended to contain all of the information necessary to map the simulated raw data -- which is otherwise identical to real raw data -- to the GEANT hits and tracks that are responsible for producing the observed hit patterns. This information thus allows us to trace what was done in the response chain. The table containing this information for MuID is dMuiDCMGhitRel. As discussed in the evaluation section, all of the other relevant MuID information can be calculated from this table, when combined with the data from the PRDF and PISA files.