How to process HepMC information

To access HepMC-information one can uses the method gselect that is very similar to the methods select and mcselect discussed above.

gBs = self.gselect ( 'bs' ,  "[ Beauty => ( D_s+ ==> K- K+ pi+ ) K-]CC ")

Again, as selection criteria one can use the decay descriptors or LoKi HepMC-functors.