Mattione Update 11162011

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^-).

protons

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.
• Will fit mean and σ of these distributions and use them in calculation of χ²

FDC π⁺

• Generated up to p = 9.0 GeV/c

• FDC π⁺ dE/dx vs. βγ

FDC, π⁺

• FDC π⁺ dE/dx Mean, Resolution vs. βγ

FDC, π+

FDC, π+

• FDC π⁺ dE/dx Mean, Resolution in different dx Bins vs. βγ

FDC, π+

FDC, π+

CDC π⁺

• Generated up to p = 9.0 GeV/c

• CDC π⁺ dE/dx vs. βγ

CDC, π⁺

• CDC π⁺ dE/dx Mean, Resolution vs. βγ

CDC, π+

CDC, π+

CDC vs. FDC π⁺

• CDC vs. FDC π⁺ dE/dx Mean, Resolution vs. βγ

π+

π+