The basic concept of the ReactionFilter Plugin is to use a defined physics reaction, usually described in a configuration file, to analyze the reconstructed data (REST files) event by event testing the hypothesis of the proposed reaction. It creates an output root file referred to as Physics Analysis Root Tree (PART) which in turn will be analyzed by other code like the DSelector.
The plugin applies basic PID selection criteria (time, mass, and dEdx) and by default a Kinematic Fitter to the reconstructed charged track and/or neutral showers in each each event and applies the Kinematic Fitter based on the chosen reaction requirements.
The ReactionFilter plugin is located in ReactionFilter plugin on github and depends heavily on the Analysis Library all part of the halld_recon package.
- An introduction to the ReactionFilter plugin can be found in this DocDB document and some information on the wiki in Analysis DReaction. Note that most of this documentation is 5 years old and no updates have been made since then.
- An example of how such a configuration file looks like can be found here: Create a Reaction Config File
- Important: Generally an analysis reaction is submitted to the global analysis system administrator, by the above link, who will run the reaction over the specified data set for all submitted reactions in one go. So the user will be provided with the resulting PART files. These files will have the specified reaction in their file name.
- This step by the administrator is called an Analysis Launch and details can be found here: Analysis Launch and Monitoring
- The output data (PART) will be located on the cache disk system of the jlab computing system. An example of such a location is /cache/halld/RunPeriod-2018-01/analysis/ver19/. The data is discriminated by Run-Period and version the latter referring to the software version begin used.