Difference between revisions of "Mattione Update 10312011"
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* Plot Δβ vs p for π<sup>+</sup> candidates to see proton, π<sup>+</sup> separation. | * Plot Δβ vs p for π<sup>+</sup> candidates to see proton, π<sup>+</sup> separation. | ||
− | === Details === | + | === 1234 Segmentation BCAL Time-Smear Details === |
− | * The 1234 segmentation is not available in the HDGEANT simulation, so | + | * The 1234 segmentation is not available in the HDGEANT simulation, so its BCAL shower time was smeared manually during reconstruction |
− | * | + | * The BCAL hit-time smear was disabled in mc_smear |
− | * | + | * The shower time was smeared by: σ<sub>smear</sub> = sqrt(σ<sup>2</sup><sub>t_334</sub> - σ<sup>2</sup><sub>t_334_NoSmear</sub>) * σ<sub>t_1234</sub> / σ<sub>t_334</sub> |
− | * | + | ** These time uncertainties were studied as a function of dE and θ |
− | * | + | ** The σ<sub>t_1234</sub> / σ<sub>t_334</sub> ratio was obtained from fitting the results of David Lawrence's studies of photons |
− | + | ** The σ<sup>2</sup><sub>t_334</sub> and σ<sup>2</sup><sub>t_334_NoSmear</sub> variances were determined separately for protons and pions | |
− | + | ||
− | + | === Improvements from last week's study === | |
− | + | * Looking at | |
− | + | ||
== David's BCAL Photon Time Resolution Studies == | == David's BCAL Photon Time Resolution Studies == |
Revision as of 11:26, 31 October 2011
Contents
Procedure
- Reconstruct π(1600) -> b1π events with t-slope = 2.0 (was 5.0 for X(2000)) using both the 334 and 1234 segmentations
- Plot Δβ vs p for π+ candidates to see proton, π+ separation.
1234 Segmentation BCAL Time-Smear Details
- The 1234 segmentation is not available in the HDGEANT simulation, so its BCAL shower time was smeared manually during reconstruction
- The BCAL hit-time smear was disabled in mc_smear
- The shower time was smeared by: σsmear = sqrt(σ2t_334 - σ2t_334_NoSmear) * σt_1234 / σt_334
- These time uncertainties were studied as a function of dE and θ
- The σt_1234 / σt_334 ratio was obtained from fitting the results of David Lawrence's studies of photons
- The σ2t_334 and σ2t_334_NoSmear variances were determined separately for protons and pions
Improvements from last week's study
- Looking at
David's BCAL Photon Time Resolution Studies
- γ BCAL σt vs. dE (GeV):
Time Resolution Segmentation Ratio
- γ BCAL σt_1234 / σt_334 vs. dE (GeV):
- Fits to γ BCAL σt_1234 / σt_334 vs. θ in dE bins:
- Don't trust fits at low-θ, so linearly-interpolate between 12 and 16 degrees.
BCAL π- 334 Segmentation σt Fits
- BCAL π- 334 Segmentation σt Fits vs. θ in dE bins:
X(2000) -> b1pi Events, π+ BCAL Δβ vs p
Δβ = βp - βt = p/sqrt(p*p + m*m) - path/(c*TOF)
- X(2000) -> b1pi Events, π+ BCAL Δβ vs p, 334 Segmentation:
- X(2000) -> b1pi Events, π+ BCAL Δβ vs p, 1234 Segmentation: