What is the difference?

Physics Processes, Models and Cross Sections
1

The example from /examples/extended/electromagnetic/TestEm0 is about calculating the cross section of electromagnetic and others, in the example, two methods of calculating the cross section are used:
‘’’
G4EmCalculator::ComputeCrossSectionPerVolume(energy,particle,emName[j],material,enerCut[j]);

and
G4EmCalculator::ComputeCrossSectionPerVolume(energy,particle,emName[j],material);
‘’’
one is about enerCut[j] and the other not, what is the difference between the two methods?

_Geant4 Version:_11.2.0
_Operating System:_Ubuntu 20.04
Compiler/Version: 9.4.0
_CMake Version:_3.16.3

2

This line. If cut is not provided defaults to 0 and it uses the cut for electrons. The cross reference library is a useful tool to get familiar with if your IDE can’t access the geant4 libraries for some reason.

3

@jrellin , thank you for the excellent reply!