The utilization of τ pairs in determining the tracking efficiency at the BaBar experiment

Abstract

This thesis presents the detailed measurements of the tracking efficiency of the BaBar detector using T pair events. These efficiency measurements are critical for many physics analyses at BaBar. The tracking efficiency is dctcrmined both as a global valuc for the detector and in terms of the parameters on which the BaBar tracking reconstruction software depends. In addition, the charge asymmetry of the tracking efficiency as well as a detailed analysis of the systematic uncertainties related to this method are also presented. It was discovered that the sample of data conventionally used by BaBar for measuring the efficiency is contaminated by background and a ncw protocol for measuring thc cfficicncies is presented. Undcr this new protocol, the global tracking efficiency correction factor and the global tracking efficiency charge asymmetry are determined to be consistent with zero. A new method for determining the efficiency as a function of the reconstruction parameters, was also successfully demonstrated.