document the change in the production yield of kaons between Geant4 versions 9.6.p04 and 10.1.p02
Explain and document the change in the production yield of kaons
(electron neutrinos) between versions 9.6.p04 and 10.1.p02 when
120 GeV protons strike thin Carbon target
#1 Updated by Hans-Joachim Wenzel about 5 years ago
- File proton-C-31GeV-K-pi-ratio-qgsp-regre-g4.10.1.p01.gif proton-C-31GeV-K-pi-ratio-qgsp-regre-g4.10.1.p01.gif added
- File proton-C-31GeV-K-pi-ratio-qgsp-regre-g4.10.2.gif proton-C-31GeV-K-pi-ratio-qgsp-regre-g4.10.2.gif added
- Status changed from Assigned to Resolved
- Assignee changed from Julia Yarba to Hans-Joachim Wenzel
- % Done changed from 0 to 100
The changes as reported by Paul Lebrun are well understood and documented by the geant 4 collaboration (see e.g. release notes for geant 4 release 4.10.1
https://geant4.web.cern.ch/geant4/support/ReleaseNotes4.10.1.html or see validation results concerning k/pi ratio from validation test 19: High energy test, provides comparison with NA61 (31 GeV/c proton beam) and NA49 (158 GeV/c proton beam) data sets which can be found in the geant 4 validation databases). We also contacted he experts to discuss our observation.
There have been number of changes in geant 4 QGS model. The changes started out as early as Geant4.10.0 series, and propagated into geant4.10.1 cycle, including geant4.10.1.p02. Motivation for the change was to make the geant 4 implementation to closer resemble the original theoretical paper. The changes while yet incomplete resulted in a better agreement of kaon/pion production ratio between simulation and experiment. This is documented in the attached figures which have been extracted from the Geant 4 validation repository:
We have kept Paul Lebrun in loop and communicated our findings.
The experimental data which was used to make the plots is at lower proton incident energies than what is used at the numi beam line. We are evaluating if data from the fermilab mipp experiment can be used for future validation (same proton energy).