Electron Analysis

Abstract

For electron selection in the PHENIX central arms, some conventional techniques for analyzing the detector signals from other than the HBD are already established and form the basis of the electron analysis. Also in the electron measurement using the HBD, we utilized these techniques as well as the HBD response information. We explain these conventional methods in the following sections. In Sect. 3.1, we introduce the basic electron selection with the PHENIX detectors. Electrons sampled by these techniques largely include photonic and non-photonic background. In the previous measurement, two methods, “cocktail method” and “converter method”, were used to estimate the background fraction [1]. Though our new measurement with the HBD basically does not use these methods other than a part of the “cocktail method” results of dielectron decays of light vector mesons, we briefly explain these estimation methods to make clear the difference of the analysis techniques between the new and previous measurements. The detailed description about these methods can also be found elsewhere [1]. With the improved purity from the HBD, the double-spin asymmetry of the heavy flavor electrons was obtained. In Sect. 3.2, we discuss how the electron analysis and the purification of the heavy flavor electron using the HBD were performed.