Fractional charge in monopole package

Dear users,
I wonder if you have experience using the GEANT4 example monopole (geant4/examples/extended/exoticphysics/monopole). I would like to study the monopole with fractional magnetic charges (Qmag). The energy deposit, to my knowledge, is proportional to the magnetic charge square (Qmag^2). In order to test it, first I simply changed Qmag from 1 to 2 and keep other parameters like monopole mass (100 GeV) and energy (100 GeV) as default. The energy deposit (h1 in the output monopole.root) changed as expected and so on when Qmag=3, 4, etc. However, when I changed Qmag from 1 to 0.1 (or 0.01), the energy deposit was always the same as when Qmag = 1. The physics process (G4MonopoleEquation) seems to have the correct equations where the energy deposit is proportional to Qmag^2. I wonder if you know how to debug this. Thank you very much.



please, specify Geant4 version.


I’ve tried geant4.10.07.p04. Thanks.

I’ve tested Geant4.11.1.2 but the results are the same.
The following figures show the h1 in the output monopole.root with different magnetic charges, showing Edep along the absorber… h1_0 is when Q=1, h1_1 is when Q=0.1 and h1_2 is when Q=10. It is obvious that h1_2 and h1_0 are very different because of the magnetic charge. When h1_0 and h1_1 have different Q, h1_0 and h1_1 are still similar, which implied something is wrong in the code.

monopole_h1.pdf (132.0 KB)