About TwoBodyDecayGen
The class TwoBodyDecayGen implements a decay tree for 2-body decays.
It achieves this by implementing a decay node as which is only aware
of the particle masses associated to itself and holds a handle to the
daughter nodes through pointers. This serves as a building block to
build the entire decay tree in an extremely flexible fashion. The
class provides a phase space event generation interface by wrapping
around the ROOT class TGenPhaseSpace. It also supports
implementing branching fractions for different decay channels by
assigning weights to each decay node.