Difference between revisions of "Mattione Kaon PID Studies eta1Prime(2300)"

Revision as of 20:28, 15 September 2012

Reaction

• γ p → η'₁(2300), p
  • η'₁(2300) → K*(892)⁰, K⁰_bar
    • K*(892)⁰ → K⁺, π^-
      • K⁰_bar → π⁺, π^-
• Final State: p, K⁺, π^-, π⁺, π^-
• Events generated with: Γ_η'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

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.

All	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus HeDC MissingP VertexP4KinFit EtaPrime2300bkgnd.png He DC	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus GasThresh MissingP VertexP4KinFit EtaPrime2300bkgnd.png Gas Threshold
	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus RICH MissingP VertexP4KinFit EtaPrime2300bkgnd.png RICH	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus LHCbRICH MissingP VertexP4KinFit EtaPrime2300bkgnd.png LHCb RICH

Cherenkov Detector Comparison: 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.

All	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus HeDC MissingP VertexP4KinFit EtaPrime2300bggen.png He DC	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus GasThresh MissingP VertexP4KinFit EtaPrime2300bggen.png Gas Threshold
	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus RICH MissingP VertexP4KinFit EtaPrime2300bggen.png RICH	File:Mattione Update 09132012 PVsTheta PiPlusPassKPlus LHCbRICH MissingP VertexP4KinFit EtaPrime2300bggen.png LHCb RICH

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)

•  % of BAD reconstructed combos remaining (BAD combo: a combo where at least one track has the wrong THROWN PID)

genr8 η'₁(2300) Background Events

•  % of reconstructed combos remaining

bggen Background Events

•  % of reconstructed combos remaining