VMC vs. generator

Hi,

What is the difference between a VMC backend and a generator?
Follow up: What is the most preferable settings for simulations? (I have seen Pythia as generator and Geant4 as VMC, but why exactly this setting?)

Best regards,
Zlatko

The generator generates the particles coming out from a collision. Pythia8 or pythia8hi are widely used generators for p-p / Pb-Pb collisions. We often test the simulation using these standards but in reality Monte Carlo production might use more specialized generators (for specific signals) or a mix of them.

Virtual Monte Carlo (VMC) is an abstraction API to talk to particle transport simulation packages. This is either Geant3 or Geant4. Either of them should be fine for testing purposes. Geant4 is the industry standard.

Thank you for a great explanation, Sandro!