HOWTO extract photons or pi0's from the framework

Many people will want to analyze final states with photons. There are several key high-level analysis objects for doing this. Unless you are doing calorimetry diagnostics it is not recommend that utilize any other object besides the ones listed below. This is because various corrections to the reconstructed photon four-momentum are applied through the reconstruction chain. Using the high level objects below guarantees that you will get a photon which has the current best measurement of the four-momentum and its error matrix.

Using DPhoton objects

The DPhoton objects contain a list of all (assumed) photons reconstructed by the FCAL and the BCAL. This