$\gamma \gamma n$ Event Candidates

After employing all the cuts as described in the preceding sections, from the analysis of the $\pi ^-p\rightarrow \gamma \gamma n$ data that consisted of a total of $3.1 \times 10^{11}$ pion stops in liquid hydrogen, 635 two-photon events survived. The energy-angle spectra of these two-photon events are shown in Figure 5.11.

Subtraction of the remaining background due to cut inefficiencies as well as determination of the absolute two-photon acceptance of the RMC detector is presented next in Chapter 6 along with the final results of the measurement.