EM Pen
This physics list uses “Penelope” Geant4 electromagnetic physics as built by the G4EmPenelopePhysics
constructor.
Specific low-energy Penelope models are used for gamma, \(e^-\), and \(e^+\) below
1 GeV. Above 1 GeV and for all other charged particles the configuration is the same
as in the G4EmStandardPhysics_option4
constructor.