Merge pull request #5639 from bendavid/gentaufix_53x

add (and enable) option to override SPINUP in lhe file for Pythia8 tau decays
cms-sw · Oct 3, 2014 · 1413707 · 1413707
2 parents 8534dbf + af2c290
commit 1413707
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Showing 5 changed files with 15 additions and 2 deletions.
diff --git a/Configuration/Generator/python/Pythia8CommonSettings_cfi.py b/Configuration/Generator/python/Pythia8CommonSettings_cfi.py
@@ -9,5 +9,6 @@
       'ParticleDecays:limitTau0 = on',
       'ParticleDecays:tau0Max = 10',
       'ParticleDecays:allowPhotonRadiation = on',
+      'ParticleDecays:tauIgnoreSpinUpCMSSW = on',
     )
 )
diff --git a/GeneratorInterface/Pythia8Interface/plugins/LHAupLesHouches.cc b/GeneratorInterface/Pythia8Interface/plugins/LHAupLesHouches.cc
@@ -67,6 +67,9 @@ bool LHAupLesHouches::setEvent(int inProcId, double mRecalculate)
 
   unsigned int iscale = 0;
   for(int i = 0; i < hepeup.NUP; i++) {
+    //override spinup flag if so configured
+    double spinup = (std::abs(hepeup.IDUP[i])==15 && ignoreTauSpinUp_) ? 9. : hepeup.SPINUP[i];
+
     //retrieve scale corresponding to each particle
     double scalein = -1.;
 
@@ -87,7 +90,7 @@ bool LHAupLesHouches::setEvent(int inProcId, double mRecalculate)
                 hepeup.PUP[i][0], hepeup.PUP[i][1],
                 hepeup.PUP[i][2], hepeup.PUP[i][3],
                 hepeup.PUP[i][4], hepeup.VTIMUP[i],
-                hepeup.SPINUP[i],scalein);
+                spinup, scalein);
   }
 
   infoPtr->eventAttributes->clear();

diff --git a/GeneratorInterface/Pythia8Interface/plugins/LHAupLesHouches.h b/GeneratorInterface/Pythia8Interface/plugins/LHAupLesHouches.h
@@ -21,7 +21,7 @@
 
 class LHAupLesHouches : public Pythia8::LHAup {
   public:
-    LHAupLesHouches() {;}
+    LHAupLesHouches() : ignoreTauSpinUp_(false) {;}
 
     //void loadRunInfo(const boost::shared_ptr<lhef::LHERunInfo> &runInfo)
     void loadRunInfo(lhef::LHERunInfo* runInfo)
@@ -30,12 +30,16 @@ class LHAupLesHouches : public Pythia8::LHAup {
     //void loadEvent(const boost::shared_ptr<lhef::LHEEvent> &event)
     void loadEvent(lhef::LHEEvent* event)
       { this->event = event; }
+
+    void setIgnoreTauSpinUp(bool b) { ignoreTauSpinUp_ = b; }
 
   private:
 
     bool setInit();
     bool setEvent(int idProcIn, double mRecalculate = -1.);
 
+    bool ignoreTauSpinUp_;
+
     //boost::shared_ptr<lhef::LHERunInfo> runInfo;
     lhef::LHERunInfo* runInfo;
     //boost::shared_ptr<lhef::LHEEvent>	event;

diff --git a/GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc b/GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc
@@ -395,7 +395,10 @@ bool Pythia8Hadronizer::initializeForExternalPartons()
   } else {
 
     lhaUP.reset(new LHAupLesHouches());
+    lhaUP->setIgnoreTauSpinUp(fMasterGen->settings.flag("ParticleDecays:tauIgnoreSpinUpCMSSW"));
     lhaUP->loadRunInfo(lheRunInfo());
+
+
 
     if ( fJetMatchingHook )
     {

diff --git a/GeneratorInterface/Pythia8Interface/src/Py8InterfaceBase.cc b/GeneratorInterface/Pythia8Interface/src/Py8InterfaceBase.cc
@@ -17,6 +17,8 @@ Py8InterfaceBase::Py8InterfaceBase( edm::ParameterSet const& ps )
   fMasterGen.reset(new Pythia);
   fDecayer.reset(new Pythia);
 
+  fMasterGen->settings.addFlag("ParticleDecays:tauIgnoreSpinUpCMSSW",false);
+
   fMasterGen->readString("Next:numberShowEvent = 0");
   fDecayer->readString("Next:numberShowEvent = 0");