Problem 1713

Summary: eta_prime decay channels missing
Product: Geant4 Reporter: o.freyermuth
Component: processes/decayAssignee: kurasige
Status: RESOLVED FIXED    
Severity: normal    
Priority: P5    
Version: 10.1   
Hardware: All   
OS: All   

Description o.freyermuth 2015-02-12 23:22:45 CET 
Dear Geant'ers, 

we noticed in our analysis that two important and well-established eta_prime decay channels are missing from the most up-to-date list used in Geant4, and also the branching ratios are slightly off: 
http://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/ForApplicationDeveloper/html/AllResources/TrackingAndPhysics/particleList.src/mesons/omega.html

This list is missing the decay to gamma+gamma and also the decay to omega+gamma. 
Both these decay channels are interesting for all meson photoproduction experiments, and the PDG lists branching ratios for these: 
http://pdg.lbl.gov/2014/listings/rpp2014-list-eta-prime-958.pdf

Could these be added to the eta_prime decay list in Geant4 / is there a reason they were left out? 

Thanks!
Oliver
Comment 2 kurasige 2015-02-16 10:26:56 CET 
Thank you for reporting the bug.

No reason why they were left out. Just forgot adding.
G4EtaPrime.cc will be updated as follows.

  // EtaPrime -> eta + pi+ + pi-
  mode[0] = new G4PhaseSpaceDecayChannel("eta_prime",0.429,3,"eta","pi+","pi-");
  // EtaPrime -> eta + pi0 + pi0
  mode[1] = new G4PhaseSpaceDecayChannel("eta_prime",0.222,3,"eta","pi0","pi0");
  // EtaPrime -> rho0 + gamma
  mode[2] = new G4PhaseSpaceDecayChannel("eta_prime",0.291,2,"rho0","gamma");
  // EtaPrime -> gamma + gamma
  mode[3] = new G4PhaseSpaceDecayChannel("eta_prime",0.0220,2,"gamma","gamma");
  // EtaPrime -> omega + gamma
  mode[4] = new G4PhaseSpaceDecayChannel("eta_prime",0.0275,2,"omega","gamma");

Thanks
Hisaya
Comment 3 o.freyermuth 2015-02-16 19:19:45 CET 
Thanks a lot for the quick fix, Hisaya! 

Greetings, 
Oliver