Code for the production of the ntuples of the Eta decays analysis

Code to create the ntuples for the analysis of multiple \eta and \eta^\prime decays. Namely, we are looking for \eta\to \mu^+\mu^-, \eta^\prime \to \mu^+\mu^-, \eta\to \pi^+\pi^-\mu^+\mu^-, and \eta^\prime\to\pi^+\pi^-\mu^+\mu^-.

The \eta and \eta^\prime come from either a D_s^+ or a D^+. The normalization channel is \phi\to\mu^+\mu^-, where again \phi comes from either a D_s^+ or a D^+.