Calculate a heavy neutrino flux from a dk2nu format neutrino beamline simulation.
This creates a TH2D named h_HN{mu/e}_d{DD}_{LLL}, with neutrino momentum on the x-axis, and heavy neutrino mass on the y-axis. dDD is the decay type (ndecay in dk2nu format, e.g. d05 is K+ decay). LLL is a location, defined in the dkMeta tree of the input.
The normalisation is such that each parent decays producing a heavy neutrino with 100% probability. A different flux is created for the muon coupling h_HNmu_... and electron coupling h_HNe_..., to allow your analysis to change the coupling constants independently.
Also creates a TH1D of the light neutrino flux, for comparison.
Also creates a TH2D named h_ndecay_nu{mu/e} of the decay types contributing to the heavy neutrino creation
Either compile directly, linking to ROOT and DK2NU.
Or compile within root: root -l -b heavify.C
Trying to compile directly, .L heavify.C+, will cause errors, you need to define the DK2NU include paths first.
The macro assume you have loaded DK2NU via UPS first. If using a standalone DK2NU, modify the last section of the program from the line #else // if __CINT__ is defined.