Electron-positron pair production: Numerical instable energy asymmetry sampling #382
Description
For electron-positron pair production by photons: When sampling the energy asymmetry x = E_electron / (E_electron + E_positron), one would expect a symmetric distribution.
If I sample a distribution for x, however, this is not fulfilled. See this example where I sample x for a photon energy of 10 MeV:
Same problem for Tsai instead of KochMotz:
The issue persists when going to higher energies, here for a photon energy of 1e5 MeV:
In each case, X Interpol refers to the secondary calculation using the CrossSectionInterpol functions, while X Integral refers to calculations based on the CrossSectionIntegral functions. The integral calculations seems to be fine, while only the interpol calculations behave incorrectly.