Mattione Kaon PID Studies eta1Prime(2300)
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Contents
Reaction
- γ p → η'1(2300), p
- η'1(2300) → K*(892)0, K0_bar
- K*(892)0 → K+, π-
- K0_bar → π+, π-
- K*(892)0 → K+, π-
- η'1(2300) → K*(892)0, K0_bar
- Final State: p, K+, π-, π+, π-
- Events generated with: Γη'1(2300) = 200 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 η'1(2300) Signal | genr8 η'1(2300) Background | bggen Background |
|---|---|---|---|
| Confidence Level |  |
 |
 |
| K0 Mass |  |
 |
 |
| Missing Mass |  |
 |
 |
| K*(892)0 Mass |  |
 |
 |
| η'1(2300) Mass |  |
 |
 |
Cherenkov Detector Comparison
genr8 η'1(2300) Background
- 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.
| Design | % of Pions That Fail Kaon Cut | Pions That Fail Kaon Cut | Pions That Survive Kaon Cut |
|---|---|---|---|
| All |  |
NA | NA |
| He DC | 30.02% |  |
 |
| Gas Threshold | 36.01% |  |
 |
| RICH | 71.93% |  |
 |
| LHCb RICH | 81.41% |  |
 |
bggen Background
- 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.
| Design | % of Pions That Fail Kaon Cut | Pions That Fail Kaon Cut | Pions That Survive Kaon Cut |
|---|---|---|---|
| All |  |
NA | NA |
| He DC | 26.01% |  |
 |
| Gas Threshold | 32.77% |  |
 |
| RICH | 51.69% |  |
 |
| LHCb RICH | 64.86% |  |
 |
Yields %'s
- ALL yield %'s are determined in the signal region (track combinations with invariant mass outside of the signal region are ignored)
genr8 η'1(2300) 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 |
|---|---|---|---|---|---|
| 1.50% | 1.73% | e% | f% |
- % of BAD reconstructed combos remaining (BAD combo: a combo where at least one track has the wrong THROWN PID)
| Stage | Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
|---|---|---|---|---|---|---|
| w/o CKOV | 0.61% | 0.58% | e% | f% | ||
| He DC | 0.59% | 0.56% | e% | f% | ||
| Gas Thresh. | 0.60% | 0.57% | e% | f% | ||
| RICH (Yi) | 0.58% | 0.55% | e% | f% | ||
| LHCb RICH | 0.57% | 0.54% | e% | f% |
genr8 η'1(2300) Background Events
- % of reconstructed combos remaining
| Stage | Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
|---|---|---|---|---|---|---|
| w/o CKOV | 0.94% | 1.01% | e% | f% | ||
| He DC | 0.67% | 0.72% | e% | f% | ||
| Gas Thresh. | 0.60% | 0.68% | e% | f% | ||
| RICH (Yi) | 0.33% | 0.32% | e% | f% | ||
| LHCb RICH | 0.23% | 0.23% | e% | f% |
bggen Background Events
- % of reconstructed combos remaining
| Stage | Missing p, No KinFit | Missing p, P4 KinFit | Missing p, VertexP4 KinFit | No Missing, No KinFit | No Missing, P4 KinFit | No Missing, VertexP4 KinFit |
|---|---|---|---|---|---|---|
| w/o CKOV | b% | c% | e% | f% | ||
| He DC | b% | c% | e% | f% | ||
| Gas Thresh. | b% | c% | e% | f% | ||
| RICH (Yi) | b% | c% | e% | f% | ||
| LHCb RICH | b% | c% | e% | f% |
