Problem 2228

Summary: GEANT4 elastic scattering model selection ability
Product: Geant4 Reporter: yoshikazu.nagai
Component: physics_listsAssignee: Alberto.Ribon
Status: RESOLVED FIXED    
Severity: enhancement CC: Gunter.Folger, Vladimir.Ivantchenko
Priority: P4    
Version: other   
Hardware: All   
OS: All   

Description yoshikazu.nagai 2020-02-13 14:19:32 CET 
(Below discussion has been already initiated with Alberto Ribon, but I post same topic here to be able to track the status)

Between Geant4 10.4 and 10.5, the default model of elastic scattering in many physics lists (e.g. FTFP_BERT) has changed, and it brings elastic scattering cross-section change up to 10% for proton 60 GeV and 120 GeV interactions on several materials.

I heard that there are two models on elastic scattering:
1. Chips cross section (class G4ChipsProtonElasticXS)
2. Barashenkov-Glauber-Gribov cross section (class G4BGGNucleonElasticXS)

Is there any possibility introducing a switch to choose a model without hacking Geant4 codes and without re-installation?
For analysis, we need to estimate systematic uncertainty coming from different model predictions, and we would like to use both models from the same Geant4 version.
Comment 1 Alberto.Ribon 2020-02-17 17:14:14 CET 
The feature you are requiring is in our plan of work for 2020.
Comment 2 yoshikazu.nagai 2020-09-10 22:21:36 CEST 
Do you foresee that this feature will be implemented for the next G4 version 10.7?
Our collaboration (NA61/SHINE) now wants to move to the later version of G4 version but still one show stopper is this feature relating to elastic scattering model.

Thanks,
Yoshikazu
Comment 3 Alberto.Ribon 2020-09-11 10:34:37 CEST 
Dear Yoshikazu,
yes, it is basically already included in our development version, and therefore will be released, in December, in G4 10.7.
We still have to test it, but we should have time for this before the release!
Alberto