Spring 2017 Analysis Launch Cuts
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Revision as of 12:11, 30 June 2021 by Reinhold (Talk | contribs) (→Analysis Launches Using These Cuts: : added hyperlinks to analysis launch pages in private wiki)
These cuts also apply to 2018 and 2019 GlueX data
Contents
[hide]PreSelect Cuts
- For a given DChargedTrack, at least one hypothesis must have a hit in either: BCAL/FCAL/TOF/SC.
- For a given DNeutralShower, it must at least have a shower energy of 100 MeV/c.
- For neutral showers in the BCAL, they must have hits in at least 2 cells.
Timing Cuts
- Timing cuts are applied only on the system with the best timing information available, in the order: BCAL/TOF/FCAL/SC. In other words, if a track has a hit in the TOF, then no cut is applied on the FCAL or SC time.
- Note that some hypotheses may not have a hit in any system and thus survive all of these cuts.
- Also, even if the SC is the best-available detector, no cut is placed on the timing if the track has been matched to more than one SC hit, UNLESS it's the only track in the combo.
- This is because the SC timing is not really good enough for PID over such a short flight distance, so the cut is primarily used to reject tracks from other beam bunches or ghost tracks.
- Also, all kaons are cut that:
- Do not have a hit in one of these timing detectors, AND
- Do not have enough hits in the CDC to compute dE/dx
- This is because their background is huge already, without letting these combos through.
- Cuts are re-placed after the kinematic fit, using updated momentum and vertex information.
- If a kinfit is not performed, then the timing cut at detached vertices is looser than otherwise: +/- 2ns WIDER for charged tracks, ~0.05ns for FCAL photons, ~0.5ns for BCAL photons
| PID | BCAL/RF Δt (ns) | TOF/RF Δt (ns) | FCAL/RF Δt (ns) | SC/RF Δt (ns) |
|---|---|---|---|---|
| γ | ±1.5 | NA | ±2.5 | NA |
| e+ | ±1.0 | ±0.5 | ±2.0 | ±2.5 |
| e- | ±1.0 | ±0.5 | ±2.0 | ±2.5 |
| μ+ | ±1.0 | ±0.5 | ±2.0 | ±2.5 |
| μ- | ±1.0 | ±0.5 | ±2.0 | ±2.5 |
| π+ | ±1.0 | ±0.5 | ±2.0 | ±2.5 |
| π- | ±1.0 | ±0.5 | ±2.0 | ±2.5 |
| K+ | ±0.75 | ±0.3 | ±2.5 | ±2.5 |
| K- | ±0.75 | ±0.3 | ±2.5 | ±2.5 |
| p | ±1.0 | ±0.6 | ±2.0 | ±2.5 |
| p̅ | ±1.0 | ±0.6 | ±2.0 | ±2.5 |
Track Energy Loss Cuts
| PID | CDC dE/dx (keV/cm) | FDC dE/dx (keV/cm) | SC dE/dx (MeV/cm) | TOF dE/dx (MeV/cm) | BCAL Shower_E/Track_p (c) | FCAL Shower_E/Track_p (c) |
|---|---|---|---|---|---|---|
| p | dE/dx > e^(-4.0*x + 2.25) + 1.0 | None | None | None | None | None |
| p̅ | dE/dx > e^(-4.0*x + 2.25) + 1.0 | None | None | None | None | None |
| π+ | dE/dx < e^(-7.0*p + 3.0) + 6.2 | None | None | None | None | None |
| π- | dE/dx < e^(-7.0*p + 3.0) + 6.2 | None | None | None | None | None |
| K+ | dE/dx < e^(-7.0*p + 3.0) + 6.2 | None | None | None | None | None |
| K- | dE/dx < e^(-7.0*p + 3.0) + 6.2 | None | None | None | None | None |
| e+ | dE/dx < 5.5 | None | None | None | E/p > 0.7 | E/p > 0.7 |
| e- | dE/dx < 5.5 | None | None | None | E/p > 0.7 | E/p > 0.7 |
| μ+ | dE/dx < e^(-7.0*p + 3.0) + 6.2 | None | None | None | E/p < 0.45 | E/p < 0.2 |
| μ- | dE/dx < e^(-7.0*p + 3.0) + 6.2 | None | None | None | E/p < 0.45 | E/p < 0.2 |
Mass Cuts
- Note that if there are no particles missing, there is also a cut on the missing energy: -3.0 < Missing Energy (GeV) < 3.0
- Detected Particles
| PID | Invariant Mass (GeV/c2) | Missing Mass2 (GeV/c2)2 |
|---|---|---|
| None | NA | -0.1 < MM2 < 0.1 |
| γ | NA | -0.1 < MM2 < 0.1 |
| e+ | NA | -1.0 < MM2 < 1.0 |
| e- | NA | -1.0 < MM2 < 1.0 |
| π- | None | -1.0 < MM2 < 1.0 |
| π+ | None | -1.0 < MM2 < 1.0 |
| K+ | None | -1.0 < MM2 < 2.0 |
| K- | None | -1.0 < MM2 < 2.0 |
| p | NA | -0.5 < MM2 < 4.41 |
| p̅ | NA | -0.5 < MM2 < 4.41 |
| n | None | -0.5 < MM2 < 4.41 |
- Decaying Mesons
| PID | Invariant Mass (GeV/c2) | Missing Mass2 (GeV/c2)2 |
|---|---|---|
| π0 | 0.08 < IM < 0.19 | -1.0 < MM2 < 1.0 |
| KS | 0.3 < IM < 0.7 | -1.0 < MM2 < 2.0 |
| η | 0.35 < IM < 0.75 | None |
| ω | 0.4 < IM < 1.2 | None |
| η' | 0.6 < IM < 1.3 | None |
| φ | 0.8 < IM < 1.2 | None |
| D0 | 1.8 < IM < 1.92 | None |
| J/ψ | None | None |
- Decaying Baryons
| PID | Invariant Mass (GeV/c2) | Missing Mass2 (GeV/c2)2 |
|---|---|---|
| Λ | 1.0 < IM < 1.2 | None |
| Λ̅ | 1.0 < IM < 1.2 | None |
| Σ0 | 1.1 < IM < 1.3 | None |
| Σ+ | 1.1 < IM < 1.3 | None |
| Σ- | 1.1 < IM < 1.3 | None |
| Ξ0 | 1.1 < IM < 1.5 | None |
| Ξ- | 1.1 < IM < 1.5 | None |
| Ω- | 1.32 < IM < 2.22 | 1.44 < MM2 < 4.84 |
| Λc | 2.0 < IM < 2.6 | None |
Kinematic Fit
- If a kinematic fit has been performed, it must have converged.
Fiducial Cuts
- Implemented in August 2019, first used in Analysis Launch 2017-01 ver31, 2018-08 ver08, and 2018-08 ver02
- Maximum Z in BCal: 393.0cm
- Maximum R in FCal: 105.5cm
- Block innermost 16 FCal channels around the beam hole
Analysis Launches Using These Cuts
- Spring 2016: ver09 -> ver17 (as of Aug.30, 2018)
- Spring 2017: ver05 -> ver16 (as of Aug.30, 2018)
