Merge pull request #20108 from zhangzc11/71X_dev_longLived_sendDaught…

…erToGeant4 backport from 93X to 71X - for neutral non-detectable exotic - send their daughters to Geant4
cms-sw · Aug 30, 2017 · 7890a59 · 7890a59
2 parents c467a50 + a4dea2a
commit 7890a59
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Showing 3 changed files with 20 additions and 2 deletions.
diff --git a/SimG4Core/Generators/BuildFile.xml b/SimG4Core/Generators/BuildFile.xml
@@ -5,6 +5,7 @@
 <use   name="FWCore/MessageLogger"/>
 <use   name="SimDataFormats/GeneratorProducts"/>
 <use   name="boost"/>
+<use   name="heppdt"/>
 <use   name="geant4core"/>
 <use   name="rootmath"/>
 <use   name="expat"/>
diff --git a/SimG4Core/Generators/interface/Generator.h b/SimG4Core/Generators/interface/Generator.h
@@ -34,6 +34,7 @@ class Generator
 
   bool particlePassesPrimaryCuts(const G4ThreeVector& p) const;
   bool isExotic(HepMC::GenParticle* p) const;
+  bool isExoticNonDetectable(HepMC::GenParticle* p) const;
   void particleAssignDaughters(G4PrimaryParticle * p, HepMC::GenParticle * hp, 
 			       double length);
   void setGenId(G4PrimaryParticle* p, int id) const 

diff --git a/SimG4Core/Generators/src/Generator.cc b/SimG4Core/Generators/src/Generator.cc
@@ -6,6 +6,8 @@
 
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
+#include "HepPDT/ParticleID.hh"
+
 #include "G4Event.hh"
 
 #include "G4HEPEvtParticle.hh"
@@ -150,7 +152,7 @@ void Generator::HepMC2G4(const HepMC::GenEvent * evt_orig, G4Event * g4evt)
       // 2:  particles are decayed by generator but need to be propagated by GEANT
       // 3:  particles are decayed by generator but do not need to be propagated by GEANT
       int status = (*pitr)->status();
-      if (status > 3 && isExotic(*pitr)) {
+      if (status > 3 && isExotic(*pitr) && (!(isExoticNonDetectable(*pitr)))) {
         // In Pythia 8, there are many status codes besides 1, 2, 3.
         // By setting the status to 2 for exotic particles, they will be checked:
         // if its decay vertex is outside the beampipe, it will be propagated by GEANT.
@@ -226,7 +228,7 @@ void Generator::HepMC2G4(const HepMC::GenEvent * evt_orig, G4Event * g4evt)
       double decay_length = 0.0;
       int status = (*pitr)->status();
 
-      if (status > 3 && isExotic(*pitr)) {
+      if (status > 3 && isExotic(*pitr) && (!(isExoticNonDetectable(*pitr))) ) {
 	status = 2;
       }
 
@@ -525,6 +527,20 @@ bool Generator::isExotic(HepMC::GenParticle* p) const
   return false;
 }
 
+bool Generator::isExoticNonDetectable(HepMC::GenParticle* p) const
+{
+  int pdgid = abs(p->pdg_id());  
+  HepPDT::ParticleID pid(p->pdg_id());
+  int charge = pid.threeCharge();
+  if ((charge==0) && (pdgid >= 1000000 && pdgid <  1000040)) // SUSY 
+    {
+    return true;
+  } 
+
+  return false;
+}
+
+
 
 void Generator::nonBeamEvent2G4(const HepMC::GenEvent * evt, G4Event * g4evt) 
 {