Mattione Kaon PID Studies h2Prime(2600)
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Contents
Reaction
- γ p → h'2(2600), p
- h'2(2600) → K1(1400)+, K-
- K1(1400)+ → K*(892)0, π+
- K*(892)0 → K+, π-
- K1(1400)+ → K*(892)0, π+
- h'2(2600) → K1(1400)+, K-
- Final State: p, K-, π+, K+, π-
- Events generated with: Γh'2(2600) = 100 MeV/c2, t-slope = 5.0, 50.0 < Vertex-Z (cm) < 80.0
Analysis Overview
- For each q = +/- particle in the reaction, all detected q = +/- tracks are tested as to whether or not they are that particle
- e.g. If a q = + track has PID FOM > 1% for both the π+ & K+: allow both combinations (DO NOT take the best FOM as true!)
- Maximum of 8 tracks per event (to cut down on memory spikes).
- The analysis (cuts/histing/kinfits) is then performed on each possible track combination (events are only cut if every one of their track combinations is cut):
- Required 45.0 < Track-Vertex-Z (cm) < 85.0
- EXTREMELY loose mass cuts around each mass peak (typically at the histogram edges): saves time by reducing # of kinematic fits to perform
- Require the combined FOM for PID (χ2 and NDF of all tracks summed together) be > 1%
- Where kinematic fit: Require that the confidence level from the kinematic fit be > 1%
- Mass cuts as illustrated.
Mass Peaks & Kinematic Fitting
- NOTES:
- Plots are shown for "Missing p, VertexP4 KinFit" only.
- Mass Plots: Pre-KinFit is Magenta, Post-KinFit is Teal
- Kinematic Fit Confidence Level is zoomed in: spike at 0 confidence is well off the top of the plot
- For the genr8 background, It wasn't possible to lineup every mass peak (without generating the recoil proton at a bogus mass), so the missing mass peak is a little off-center.
- If a cut is shown, then all "Post-KinFit" plots after that cut include it.
Plot | genr8 h'2(2600) Signal | genr8 h'2(2600) Background | bggen Background |
---|---|---|---|
Confidence Level | |||
Missing Mass | |||
K*(892)0 Mass | |||
K1(1400)+ Mass | |||
h'2(2600) Mass |
Cherenkov Detector Comparison
genr8 h'2(2600) Background: K+'s
- P vs. θ of π+'s as K+ candidates ("All" means all post-analysis cuts, pre-Cherenkov cuts)
- Plots are shown for "Missing p, VertexP4 KinFit" only.
Detector | % of Pions That Fail Kaon Cut | Pions That Fail Kaon Cut | Pions That Survive Kaon Cut |
---|---|---|---|
No CKOV | NA | NA | |
He DC | 22.20% | ||
Gas Threshold | 20.78% | ||
HBRICH | 76.86% | ||
LHCb RICH | 79.25% |
genr8 h'2(2600) Background: K-'s
- P vs. θ of π-'s as K- candidates ("All" means all post-analysis cuts, pre-Cherenkov cuts)
- Plots are shown for "Missing p, VertexP4 KinFit" only.
Detector | % of Pions That Fail Kaon Cut | Pions That Fail Kaon Cut | Pions That Survive Kaon Cut |
---|---|---|---|
No CKOV | NA | NA | |
He DC | 28.86% | ||
Gas Threshold | 35.31% | ||
HBRICH | 50.99% | ||
LHCb RICH | 67.77% |
bggen Background: K+'s
- P vs. θ of π+'s as K+ candidates ("All" means all post-analysis cuts, pre-Cherenkov cuts)
- Plots are shown for "Missing p, VertexP4 KinFit" only.
Detector | % of Pions That Fail Kaon Cut | Pions That Fail Kaon Cut | Pions That Survive Kaon Cut |
---|---|---|---|
No CKOV | NA | NA | |
He DC | 22.87% | ||
Gas Threshold | 20.76% | ||
HBRICH | 65.65% | ||
LHCb RICH | 71.76% |
bggen Background: K-'s
- P vs. θ of π-'s as K- candidates ("All" means all post-analysis cuts, pre-Cherenkov cuts)
- Plots are shown for "Missing p, VertexP4 KinFit" only.
Detector | % of Pions That Fail Kaon Cut | Pions That Fail Kaon Cut | Pions That Survive Kaon Cut |
---|---|---|---|
No CKOV | NA | NA | |
He DC | 21.69% | ||
Gas Threshold | 28.71% | ||
HBRICH | 49.84% | ||
LHCb RICH | 59.30% |
Yield %'s & Signal / Background Ratios
- ALL data are determined in the signal region (track combinations with invariant mass outside of the signal region are ignored), and from Eγ = 8.5 - 9.0 GeV
Yield %'s
- % of generated events remaining after all cuts (including a final cut requiring that all tracks have the correct THROWN PID)
Detector / PID Cut | Missing p, No Fit | Missing p, P4 Fit | Missing p, VertexP4 Fit | No Missing, No Fit | No Missing, P4 Fit | No Missing, VertexP4 Fit |
---|---|---|---|---|---|---|
No CKOV | 5.12568% | 4.95312% | 2.99637% | 2.1999% | 1.31276% | 0.98661% |
He DC K: 1 Exclusive |
3.40657% | 3.29236% | 2.05918% | 1.514% | 0.925587% | 0.698757% |
Gas Threshold K: 1 Exclusive |
3.89032% | 3.75968% | 2.31741% | 1.70962% | 1.04419% | 0.785577% |
HBRICH K: 1 Exclusive |
4.32309% | 4.17475% | 2.61845% | 1.91705% | 1.20329% | 0.909531% |
LHCb RICH K: 1 Exclusive |
4.07889% | 3.92964% | 2.43328% | 1.79283% | 1.10076% | 0.829916% |
Signal / Background Ratios
- Signal / Background Ratios
Detector / PID Cut | Missing p, No Fit | Missing p, P4 Fit | Missing p, VertexP4 Fit | No Missing, No Fit | No Missing, P4 Fit | No Missing, VertexP4 Fit |
---|---|---|---|---|---|---|
No CKOV | 0.000500823 | 0.000570429 | 0.0047081 | 0.00607969 | 0.0970875 | 0.181681 |
He DC K: Inclusive |
0.000619695 | 0.000706717 | 0.00650644 | 0.00859298 | 0.113015 | 0.176589 |
Gas Threshold K: Inclusive |
0.000680933 | 0.000771428 | 0.00744195 | 0.0103961 | 0.117505 | 0.176502 |
HBRICH K: Inclusive |
0.00104882 | 0.00115179 | 0.0122539 | 0.0166758 | 0.130213 | 0.187071 |
LHCb RICH K: Inclusive |
0.000880024 | 0.000983796 | 0.0103902 | 0.0141128 | 0.131352 | 0.173167 |
He DC K: 1 Exclusive |
0.00135639 | 0.00156158 | 0.0119952 | 0.0154022 | 0.136579 | 0.171659 |
Gas Threshold K: 1 Exclusive |
0.00144715 | 0.00166568 | 0.0123712 | 0.0151753 | 0.121752 | 0.158017 |
HBRICH K: 1 Exclusive |
0.00223502 | 0.00253165 | 0.0202096 | 0.0230668 | 0.133195 | 0.182703 |
LHCb RICH K: 1 Exclusive |
0.0019454 | 0.00222221 | 0.0167062 | 0.0197641 | 0.128297 | 0.166855 |
Signal / Background Ratios : Improvements Over No CKOV
- Detector Signal / Background Ratio (StBR) DIVIDED BY No CKOV StBR
Detector / PID Cut | Missing p, No Fit | Missing p, P4 Fit | Missing p, VertexP4 Fit | No Missing, No Fit | No Missing, P4 Fit | No Missing, VertexP4 Fit |
---|---|---|---|---|---|---|
He DC K: Inclusive |
1.23736 | 1.23892 | 1.38197 | 1.41339 | 1.16405 | 0.971973 |
Gas Threshold K: Inclusive |
1.35963 | 1.35237 | 1.58067 | 1.70997 | 1.2103 | 0.971494 |
HBRICH K: Inclusive |
2.0942 | 2.01917 | 2.60273 | 2.74287 | 1.34119 | 1.02967 |
LHCb RICH K: Inclusive |
1.75716 | 1.72466 | 2.20688 | 2.32131 | 1.35292 | 0.953137 |
He DC K: 1 Exclusive |
2.70832 | 2.73756 | 2.54777 | 2.53338 | 1.40676 | 0.944839 |
Gas Threshold K: 1 Exclusive |
2.88955 | 2.92005 | 2.62763 | 2.49606 | 1.25404 | 0.86975 |
HBRICH K: 1 Exclusive |
4.46269 | 4.43816 | 4.29252 | 3.79408 | 1.37191 | 1.00563 |
LHCb RICH K: 1 Exclusive |
3.88442 | 3.89569 | 3.54839 | 3.25083 | 1.32146 | 0.918396 |