Particle ID
From GlueXWiki
Charged Tracks
- DChargedTrackHypothesis::position() returns the position of the track at its position of closest approach to the beamline.
- DChargedTrackHypothesis::t1() is the measured hit time of the BCAL/TOF/FCAL hit/shower, if present, that is matched to the track (if hits in multiple systems, order of preference is BCAL/TOF/FCAL).
- If it is not matched to a hit, it's value is NaN (and the detector system is SYS_NULL).
- DChargedTrackHypothesis::pathLength() returns the path length along the track from it's hit in the BCAL/TOF/FCAL to position().
- DChargedTrackHypothesis::t0() is either:
- The selected RF bunch time, if present, propagated to position().
- The measured start counter hit time, if present, propagated to position().
- If neither is available, it's value is NaN (and the detector system is SYS_NULL).
- DChargedTrackHypothesis::measuredBeta() is pathLength()/(c*(t1() - t0())). Thus it is NaN if there aren't enough detector hits on the track.
