Difference between revisions of "Spring 2017 Analysis Launch Cuts"

From GlueXWiki
Jump to: navigation, search
(Track Energy Loss Cuts)
(fix small sign error)
Line 75: Line 75:
 
|-
 
|-
 
! &pi;<sup>+</sup>
 
! &pi;<sup>+</sup>
| dE/dx < e^(7.0*p + 3.0) + 6.2 || None || None || None || None || None
+
| dE/dx < e^(-7.0*p + 3.0) + 6.2 || None || None || None || None || None
 
|-
 
|-
 
! &pi;<sup>-</sup>
 
! &pi;<sup>-</sup>
| dE/dx < e^(7.0*p + 3.0) + 6.2 || None || None || None || None || None
+
| dE/dx < e^(-7.0*p + 3.0) + 6.2 || None || None || None || None || None
 
|-
 
|-
 
! K<sup>+</sup>
 
! K<sup>+</sup>
| dE/dx < e^(7.0*p + 3.0) + 6.2 || None || None || None || None || None
+
| dE/dx < e^(-7.0*p + 3.0) + 6.2 || None || None || None || None || None
 
|-
 
|-
 
! K<sup>-</sup>
 
! K<sup>-</sup>
| dE/dx < e^(7.0*p + 3.0) + 6.2 || None || None || None || None || None
+
| dE/dx < e^(-7.0*p + 3.0) + 6.2 || None || None || None || None || None
 
|-
 
|-
 
! e<sup>+</sup>
 
! e<sup>+</sup>
Line 93: Line 93:
 
|-
 
|-
 
! &mu;<sup>+</sup>
 
! &mu;<sup>+</sup>
| dE/dx < e^(7.0*p + 3.0) + 6.2 || None || None || None || E/p < 0.45 || E/p < 0.2
+
| dE/dx < e^(-7.0*p + 3.0) + 6.2 || None || None || None || E/p < 0.45 || E/p < 0.2
 
|-
 
|-
 
! &mu;<sup>-</sup>
 
! &mu;<sup>-</sup>
| dE/dx < e^(7.0*p + 3.0) + 6.2 || None || None || None || E/p < 0.45 || E/p < 0.2
+
| dE/dx < e^(-7.0*p + 3.0) + 6.2 || None || None || None || E/p < 0.45 || E/p < 0.2
 
|}
 
|}
 
<br style="clear:both;"/>
 
<br style="clear:both;"/>

Revision as of 13:02, 6 January 2020

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
±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
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
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 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)