Difference between revisions of "Particle ID"
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* <span style="color:#0000FF">DChargedTrackHypothesis</span>::<span style="color:#008000">dChiSq_Timing</span> is defined as: | * <span style="color:#0000FF">DChargedTrackHypothesis</span>::<span style="color:#008000">dChiSq_Timing</span> is defined as: | ||
** Δt = <span style="color:#008000">t0</span>() - <span style="color:#008000">time</span>() | ** Δt = <span style="color:#008000">t0</span>() - <span style="color:#008000">time</span>() | ||
| − | ** χ<sup>2</sup> = (Δt/σ<sub>Δt</sub>) | + | ** χ<sup>2</sup> = (Δt/σ<sub>Δt</sub>)<sup>2</sup> |
** With NDF = 1 (0 if not enough matching detectors). | ** With NDF = 1 (0 if not enough matching detectors). | ||
== Neutral Showers == | == Neutral Showers == | ||
Revision as of 15:39, 6 September 2015
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.
- DChargedTrackHypothesis::time() is the hit time from the ST/BCAL/TOF/FCAL system propagated to position().
- This propagation is performed step by step along the track, taking into account the energy loss of the particle at each step. Thus, it is not calculated with a constant beta.
- DChargedTrackHypothesis::dChiSq_Timing is defined as:
- Δt = t0() - time()
- χ2 = (Δt/σΔt)2
- With NDF = 1 (0 if not enough matching detectors).
