Problem 2204

Summary: Wrong sampling of scattering angle of light ion off Hydrogen
Product: Geant4 Reporter: Vladimir.Ivantchenko
Component: processes/hadronic/models/coherent_elasticAssignee: Vladimir Uzhinskiy <Vladimir.Uzhinskiy>
Status: RESOLVED FIXED    
Severity: minor CC: Alberto.Ribon
Priority: P4    
Version: 10.5   
Hardware: All   
OS: All   

Description Vladimir.Ivantchenko 2019-11-15 09:56:16 CET
Hello,

In CMS simulation this warning message is seen:

-------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : hadEla002
      issued by : G4HadronElastic::ApplyYourself
 LARGE cost ! cost=-2.80074 for anti_proton ekin=102.834 MeV on (Z,A)=(1,1)
         Projectile stops and its energy is deposited locally:
         neglected recoil of the target nucleus!
*** This is just a warning message. ***
-------- WWWW -------- G4Exception-END --------- WWWW -------

The G4AntiNuclElastic model is used. 

Vladimir
Comment 1 Vladimir.Ivantchenko 2019-11-28 04:45:26 CET
Hi Vladimir,

likely model has problem for scattering off Hydrogen.

Cheers,
Vladimir
Comment 2 Alberto.Ribon 2020-07-20 15:00:31 CEST
Vladimir Uzhinsky is working on it and he hopes to fix the problem in time for the December release.
Comment 3 Alberto.Ribon 2021-12-15 16:16:55 CET
A Merge Request that should fix the problem is under testing, but there are still a few problems to fix.
Comment 4 Alberto.Ribon 2022-01-28 15:32:57 CET
The fix has been already integrated in the development, and therefore it will be included in the next release, G4 11.1, expected for December 2022.

The fix has also been proposed for the first patch of Geant4 11.0, i.e. 11.0.p01, expected for February.

Likely, the fix will be also included in the next patch of Geant4 10.7, i.e. 10.7.p04 (date not yet scheduled).

So, I leave the bug open, but it should have been solved.
Comment 5 Vladimir.Ivantchenko 2022-09-29 19:44:04 CEST
No more warning of this type is seen during the year. So, this ticket may be closed.