Mattione Update 11302011
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Contents
DC dE/dx Study Overview
Introduction
- DC dE/dx information used for PID is bad, is disabled until fixed.
- DC dE/dx Confidence Level (for protons, similar for K+'s, π+'s, and π-).
Procedure
- Look at reconstructed dE/dx in CDC & FDC (treated separately: different gas mixtures).
- Half of the track hits in each of the FDC/CDC (those with the largest dE/dx) are ignored: truncates Landau distribution to resemble Gaussian distribution.
- Fit mean and σ of these distributions and use them in calculation of χ2
FDC
- FDC π+ dE/dx μ & σ
- σ is dependent on amount of information: # hits USED (= 1/2 of total # hits: reject largest dE/dx hits to remove Landau tail)
- FDC protons dE/dx μ & σ
- σ is dependent on amount of information: # hits USED (= 1/2 of total # hits: reject largest dE/dx hits to remove Landau tail)
CDC
- CDC π+ dE/dx μ & σ
- σ is dependent on amount of information: # hits USED (= 1/2 of total # hits: reject largest dE/dx hits to remove Landau tail)
- CDC protons dE/dx μ & σ
- σ is dependent on amount of information: # hits USED (= 1/2 of total # hits: reject largest dE/dx hits to remove Landau tail)
CDC Proton Confidence Levels
- Confidence Level of all protons with # CDC hits >= 6 (# used hits > 3)
- Confidence Level of protons with varying # of CDC hits used