Difference between revisions of "Mattione Update 07092012"
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* 40.4% of remaining f<sub>1</sub>(1285) track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 1.6%*40.4% = 0.65% of events (?) | * 40.4% of remaining f<sub>1</sub>(1285) track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 1.6%*40.4% = 0.65% of events (?) | ||
* 27.8% of remaining bggen track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 0.044%*27.8% = 0.012% of events (?) | * 27.8% of remaining bggen track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 0.044%*27.8% = 0.012% of events (?) | ||
+ | |||
+ | {| border="1" cellpadding="2" align="left" valign="top" style="text-align:center;" | ||
+ | !width="50"| Reaction | ||
+ | !width="200"| # Generated Events | ||
+ | !width="200"| % Events Survive Cuts | ||
+ | !width="200"| # Surviving Track Combos / Surviving Event | ||
+ | !width="200"| % Surviving Track Combos within +/- 2Γ (84.4%) of Y(2175) mass peak | ||
+ | !width="200"| Rough % Generated Events within +/- 2Γ (84.4%) of Y(2175) mass peak | ||
+ | |- | ||
+ | ! Y(2175) | ||
+ | | || | ||
+ | |- | ||
+ | ! f<sub>1</sub>(1285) | ||
+ | | || | ||
+ | |- | ||
+ | ! bggen | ||
+ | | || | ||
+ | |} | ||
+ | <br style="clear:both;"/> |
Revision as of 23:30, 8 July 2012
Contents
Y(2175) Study
Reaction
- γ p → Y(2175), p
- Y(2175) → π+, π-, φ
- φ → K+, K-
- Y(2175) → π+, π-, φ
- Final State: p, π+, π-, K+, K-
- ~530,000 Events Generated using genr8 with: 9 GeV Photons, ΓY(2175) = 61 MeV/c2, t-slope = 5.0, 50.0 < Vertex-Z (cm) < 80.0
Background Channel
- γ p → f1(1285), p
- f1(1285) → π+, π-, π+, π-
- NOTE: had to trick genr8 by having the f1(1285) decay to η, η, and then each decaying to π+, π-
- Final State: p, π+, π-, π+, π-
- ~530,000 Events Generated using genr8 with: 9 GeV Photons, Γf1(1285) = 24 MeV/c2, t-slope = 5.0, 50.0 < Vertex-Z (cm) < 80.0
bggen
- Generated entire photon energy region
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!)
- 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 reconstruction of 2-to-3 + Tracks, 2 - Tracks (proton is treated as missing)
- Required 45.0 < Track-Vertex-Z (cm) < 85.0
- Required DOCA between tracks < 5.0 cm
- Require the combined FOM for PID (π+, π-, K+, K-) be > 1%
- Place very loose cuts on the φ invariant mass (0.8 - 1.3) and p missing mass (0.5 - 1.4): reduces # of bogus track combinations to save time / cleanup histograms
- Phi mass cut: 1.004 < K+K- Invariant Mass (GeV/c2) < 1.04
- Kinematic Fit: 4-momentum conservation: p missing mass
- Require that the confidence level from the kinematic fit be > 1%
Thrown Track Parameters
- Thrown Track Parameters
Track | Y(2175) | f1(1285) | bggen |
---|---|---|---|
γ | |||
K+ | NA | ||
K- | NA | ||
π+ | |||
π- | |||
p |
Initial Mass Peaks
- Initial Mass Peaks
Mass Peak | Y(2175) | f1(1285) | bggen |
---|---|---|---|
φ | |||
p | |||
Y(2175) |
Kinematic Fitting
- Confidence Level
- NOTE: The pulls had sigmas of ~1.5 - 1.6, and the p_z means were +/- 0.2 (other means were 0). This is possibly due to my having an incorrect variance for the photon energy, and combinatoric background seeping into the distributions.
- NOTE: the spike at zero for these distributions is way above the top of the plots.
Fit Constraint | Y(2175) | f1(1285) | bggen |
---|---|---|---|
(p) |
Final Mass Peaks
- Final Mass Peaks
- NOTE: proton peak uses pre-kinfit track momentum, Y(2175) peak uses post-kinfit track momentum
Mass Peak | Y(2175) | f1(1285) | bggen |
---|---|---|---|
p | |||
Y(2175) |
Statistics
- 7.4% of all Y(2175) events survive all cuts (323196 Generated), with 1.17 surviving track combinations / event
- 1.6% of all f1(1285) events survive all cuts (503125 Generated), with 1.13 surviving track combinations / event
- 0.044% of all bggen events survive all cuts (1047972 Generated), with 1.31 surviving track combinations / event
- 73.8% of remaining Y(2175) track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 7.4%*73.8% = 5.5% of events (?)
- 40.4% of remaining f1(1285) track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 1.6%*40.4% = 0.65% of events (?)
- 27.8% of remaining bggen track combos are within +/- 2Γ (84.4%) of Y(2175) mass peak. 0.044%*27.8% = 0.012% of events (?)
Reaction | # Generated Events | % Events Survive Cuts | # Surviving Track Combos / Surviving Event | % Surviving Track Combos within +/- 2Γ (84.4%) of Y(2175) mass peak | Rough % Generated Events within +/- 2Γ (84.4%) of Y(2175) mass peak |
---|---|---|---|---|---|
Y(2175) | |||||
f1(1285) | |||||
bggen |