Page History

...

The HPS physics reconstruction is implemented in within the HPS Java project as a chain of org.lcsim Drivers which  (event processors) which process LCIO Data Format events that are accessed using through the EventHeader API.  The driver list is described in Drivers are described by an lcsim xml steering file, which is configured read by the lcsim job manager.  

Detector Conditions including per channel calibrations are read and applied in the initialization phase.  The data from each event is processed to produce additional output collections containing reconstructed objects such as tracks and calorimeter clusters. 

First, the raw data must be converted from EVIO Data Format using The EVIO Data Format is converted into LCIO by an LCSimEventBuilder such as LCSimEngRunEventBuilder.  The EvioToLcio command line tool reads is used to read EvioEvents with an EvioReader and then uses an the event builder to create LCIO events representing the raw data events.  The driver full Driver chain is then run on the raw data collections to perform the physics reconstruction which will add additional object collections to the event.  The combined events with the data and recon collections .  These combined events are written out to an LCIO file.  The LCIO output can , which can subsequently be converted to ROOT DST Data Format for ROOT compatibility, or it may .  The LCIO events may also be loaded back into HPS Java for analysis. 

...

1.  EVIO data files are read in and converted to LCIO events containing the raw data collections.
2. The HPS Java reconstruction is run to add physics object collections to , defined by a list of Drivers in an XML steering file, adds additional reconstructed object collections to the events.
3. The events are written to an LCIO file containing the results of the recon.
4. The recon output LCIO file can be is converted to ROOT DST Data Format for analysis.

Oftentimes, steps Steps 1-3 are typically performed in the same job (process) for efficiency using the EvioToLcio command line utility.

...

.

Reconstruction Drivers 

The reconstruction Driver chain is defined in production steering files such as EngineeringRun2015FullRecon.lcsim, which are kept in this SVN folder and typically accessed as a class resource from a jar file.

...

Algorithm Details

Data Conversion

The LCSimEventBuilder defines an interface for converting from EVIO to LCIO events, with the LCSimEngRunEventBuilder providing the current implementation of this conversion process.  EVIO collections are processed by a reader which gets raw bank data and converts it into a typed LCIO collection.

SVT data banks are handled by an SvtEvioReader and converted into RawTrackerHit and GenericObject collections.

Various modes of EVIO ECal data are converted using the EcalEvioReader.The following collections are added to the event by the ECal reader.

...

The default builder will also convert and write 

...

DAQ config information, EPICS data, and scaler bank data into the output LCSim events, if these banks are present in the EVIO data.

Track Reconstruction

These are the steps in the HPS Java track reconstruction:

...