New neutral particle with simple elastic process

Physics Processes, Models and Cross Sections
1

Hello,

I have created a new neutral particle with custom mass, charge, etc. and other properties.
I would like now to associate it with a single elastic scattering process with a fixed (perhaps
target nucleus dependent) effective cross section. Is there perhaps a similar example already in Geant4?

Thanks a lot for help.

Best,
Balint

2

Hello,

please, check $G4INSTALL/examples/extended/exotic_physics/monopole

VI

3

Hello,

Thanks a lot for this pointer. If I understand correctly, my neutral particle would be indeed quite similar to the Monopole case, when the Monopole has zero charge. In this particular case I see that in G4MonopolePhysics::ConstructProcess the main process registered is G4Transportation. While for other cases the with non-zero charge various energy loss processes are registered, eg. G4mplIonisation and a custom G4MonopoleTransportation.

So, for my neutral case the main energy loss mechanism would be giving recoil energy to a detector target nucleus. The parameters in this process are the masses of the new particle and the target nucleus, and some effective cross section. So, naively (unless I am overcomplicating it) I am guessing that I would have to create a new process class that inherits from G4VEnergyLossProcess (that is also what G4mplIonisation is inheriting from) and that handles the particle changes for the projectile and the target.

Is this correct?

Thanks a lot,
B.

4

Hello,

just to wrap this up, at the end I solved the problem by deriving a new class from G4VDiscreteProcess,
and registering the various energy deposits and momentum changes as a G4VParticleChange in PostStepDoIt, and also setting some appropriate things GetMeanFreePath. Finally, I just added this DiscreteProcess to the G4ProcessManager for my new particle. Like this it works.

Best,
B.

5

That’s exactly right! You’ve written a clean “bare minimum” process for your needs.

The process frameworks for EM and hadronic stuff in Geant4 are very complicated, but you don’t need to implement those complications yourself.