| Summary: | Energy is not conserved in the muon decay | ||
|---|---|---|---|
| Product: | Geant4 | Reporter: | Artur Shaikhiev <artur.shaikhiev> |
| Component: | processes/decay | Assignee: | kurasige |
| Status: | RESOLVED FIXED | ||
| Severity: | minor | ||
| Priority: | P4 | ||
| Version: | 10.1 | ||
| Hardware: | All | ||
| OS: | All | ||
Hi, Artur
Thank you very much for reporting the bug.
I found that calculation of beta of 2 neutrino system in CM frame was wrong.
I've committed a bug fix version (particles-V10-04-04)
Cheers,
Hisaya2072 by Hisaya'
|
Greetings, I've checked energy conservation in the G4MuonDecayChannelWithSpin generator using sum of e+, nu_mu and anti_nue energies. In terms of generator I used the sum of the following variables: total_energy = energy + daughterparticle1->Get4Momentum().e() + daughterparticle2->Get4Momentum().e(); Then I compared my total_energy variable with EMMU (which is the muon mass) by introducing the difference (total_energy - EMMU)/EMMU. So, the difference is very low ~10^{-5} - 10^{-4}. I checked 193 muon decays with this channel and found 4 events with the high difference: -0.011572, -0.015309, -0.019909, -0.007233. It means that energy is not always conserved in the muon decays (2% of considering events!). I did the same exercise for the G4MuonRadiativeDecayChannelWithSpin. My total energy in terms of generator now is: total_energy = E + G + daughterparticle2->Get4Momentum().e() + daughterparticle3->Get4Momentum().e(); And again I compared total energy with muon mass by introducing the same difference: (total_energy - EMMU)/EMMU. I checked 193 events, the difference is higher than for the non-radiative case ~(1-3)x10^{-3}, but I found two events with very high difference -0.495478, -0.496089, this is large energy deficit! So ~1% of checked events are not consistent with the energy conservation law. Is this behaviour expected or the energy conservation check have to be added to the generator? Regards, Artur