How to add particle decay?

Hello,

I’ve been searching through the particle files in geant4 and I noticed that particles like J/psi, B, D and Upsilon don’t have any decay associated to them. However, I need the following decays in my program:

B0 -> J/Psi (Psi’) X
B+/- -> J/Psi (Psi’)
B_s -> J/Psi (Psi’) X
J/Psi -> mu+ mu-
D+/- -> mu
D0 -> mu
D_s -> mu
Upsilon -> mu

Is there something I can do to add these decays?