Mattione Kaon PID Studies phi3(1850)
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Contents
Reaction
- γ p → φ3(1850), p
- φ3(1850) → K+, K-
- Final State: p, K+, K-
- Events generated with: Γφ3(1850) = 87 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 φ3(1850) Signal | genr8 φ3(1850) Background | bggen Background |
---|---|---|---|
Confidence Level | |||
Missing Mass | |||
φ3(1850) Mass |
Cherenkov Detector Comparison
genr8 φ3(1850) Background
- P vs. θ of π+'s as K+ candidates ("All" means all post-analysis cuts, pre-Cherenkov cuts)
- π-'s as K- not shown: identical due to symmetry.
- 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 | 39.13% | ||
Gas Threshold | 46.58% | ||
HBRICH | 53.69% | ||
LHCb RICH | 88.03% |
bggen Background
- P vs. θ of π+'s as K+ candidates ("All" means all post-analysis cuts, pre-Cherenkov cuts)
- π-'s as K- not shown: identical due to symmetry.
- 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 | 29.32% | ||
Gas Threshold | 40.64% | ||
HBRICH | 54.70% | ||
LHCb RICH | 75.50% |
Yields %'s
- ALL yield %'s are determined in the signal region (track combinations with invariant mass outside of the signal region are ignored)
genr8 φ3(1850) Signal Events
- % of generated events remaining after all cuts (including a final cut requiring that all tracks have the correct THROWN PID)
Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
---|---|---|---|---|---|
30.21% | 29.34% | 10.17% | 9.73% |
- % of BAD reconstructed combos remaining (BAD combo: a combo where at least one track has the wrong THROWN PID)
Detector | Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
---|---|---|---|---|---|---|
No CKOV | 11.08% | 6.56% | 10.04% | 8.11% | ||
He DC | 10.60% | 6.11% | 9.90% | 7.98% | ||
Gas Thresh. | 11.08% | 6.56% | 10.04% | 8.11% | ||
HBRICH | 10.59% | 6.10% | 9.89% | 7.97% | ||
LHCb RICH | 9.90% | 5.44% | 9.70% | 7.79% |
genr8 φ3(1850) Background Events
- % of reconstructed combos remaining
Detector | Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
---|---|---|---|---|---|---|
No CKOV | 42.99% | 40.45% | ||||
He DC | 15.47% | 14.28% | ||||
Gas Thresh. | 4.96% | 4.50% | ||||
HBRICH | 7.55% | 6.29% | ||||
LHCb RICH | 0.79% | 0.61% |
bggen Background Events
- % of reconstructed combos remaining
Detector | Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
---|---|---|---|---|---|---|
No CKOV | 3.56% | 1.86% | ||||
He DC | 2.53% | 1.17% | ||||
Gas Thresh. | 2.18% | 0.92% | ||||
HBRICH | 1.61% | 0.72% | ||||
LHCb RICH | 1.19% | 0.44% |