Difference between revisions of "Spring 2017 Analysis Launch Cuts"
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! Ω<sup>-</sup> | ! Ω<sup>-</sup> | ||
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! Λ<sub>c</sub> | ! Λ<sub>c</sub> |
Revision as of 12:25, 7 August 2017
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.
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^(0.1*p + 0.5) + 1.2 | None | None | None | None | None |
π- | dE/dx < e^(0.1*p + 0.5) + 1.2 | None | None | None | None | None |
K+ | dE/dx < e^(-2.0*p + 0.8) + 3.0 | None | None | None | None | None |
K- | dE/dx < e^(-2.0*p + 0.8) + 3.0 | None | None | None | None | None |
e+ | dE/dx < 5.5 | dE/dx < 3.5 | None | None | None | None |
e- | dE/dx < 5.5 | dE/dx < 3.5 | None | None | None | None |
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 | None |
e- | NA | None |
π- | None | -1.0 < MM2 < 1.0 |
π+ | None | -1.0 < MM2 < 1.0 |
K+ | None | None |
K- | None | None |
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 | None |
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 | None |
Λc | 2.0 < IM < 2.6 | None |
Kinematic Fit
- If a kinematic fit has been performed, it must have converged.