Uncertainties and bugs in MMC and MUM

Dmitry Chirkin

UC Berkeley

The problem

• Propagation of 100 TeV muons through 300 meters of Frejus Rock

Different Bremsstrahlung implementations

• In ice/water

Both bremsstrahlung implementations

• In Standard Rock/water

Other cross sections

• Comparison with MUM

E+- pair production

• 5% difference with MUM

All cross sections

• Comparison with MUM

The Agreement

• Between MMC and MUM

Conclusions

• MMC e+- pair production cross section was corrected. It was underestimated by 5%, which led to a ~3% error in propagation of 100 TeV muons.

• MUM 8-point integration used for e+- cross section has an insufficient precision.

• ABB and KKP bremsstrahlung cross section parameterizations differ for hydrogen. KKP is used in AMANDA and the most recent.

• All cross sections now agree between MMC and MUM, and differences can be explained.