Analysis of Data

Herein we describe the analysis of the April-May, 1999, data. Specifically, we discuss the steps we followed to firstly identify the photon-pairs emerging from the target and secondly, the methods we employed to separate the $\pi ^-p\rightarrow \gamma \gamma n$ signal from the two-photon backgrounds.

The chapter is organized as follows. In Section 5.1, we discuss the determination of the drift velocity and the time pedestals for the drift chamber. In Section 5.2, we describe the tracking cuts and photon cuts we used to identify a photon. Section 5.3 discusses the various processes that led to two-photon backgrounds, and Section 5.4 describes the various cuts we used to reject two-photon backgrounds and select two-photon event candidates.