Torben Ferber

31 May 2018

Abstract: This figure shows the invariant mass distribution of $\pi^0 \to \gamma \gamma$ in 5 pb$^{-1}$ of collision data. Events are required to contain at least three good tracks to purity the sample with processes of the type $e^+e^- \to $ hadrons, while rejecting beam induced background, Bhabha scattering, and other low multiplicity background sources. The photon daughters of the $\pi^0$ candidates are required to have an energy of greater than 150 MeV, and to be within the acceptance of the Central Drift Chamber (CDC). The internal document reference is BELLE2-NOTE-PH-2018-002.