Add possibility to trigger on generated multiplicity in PYTHIA8

alisw · Sep 6, 2019 · 9f66f64 · 9f66f64
1 parent 7734c70
commit 9f66f64
Show file tree

Hide file tree

Showing 2 changed files with 63 additions and 2 deletions.
diff --git a/PYTHIA6/AliPythia6/AliGenPythiaPlus.cxx b/PYTHIA6/AliPythia6/AliGenPythiaPlus.cxx
@@ -99,7 +99,12 @@ AliGenPythiaPlus::AliGenPythiaPlus():
     fNewMIS(kFALSE),   
     fHFoff(kFALSE),    
     fTriggerParticle(0),
-    fTriggerEta(0.9),     
+    fTriggerEta(0.9),
+    fTriggerMultiplicity(0),
+    fTriggerMultiplicityEta(0),
+    fTriggerMultiplicityEtaMin(0),
+    fTriggerMultiplicityEtaMax(0),
+    fTriggerMultiplicityPtMin(0),  
     fCountMode(kCountAll),      
     fHeader(0),  
     fRL(0),      
@@ -199,6 +204,11 @@ AliGenPythiaPlus::AliGenPythiaPlus(AliPythiaBase* pythia)
      fHFoff(kFALSE),    
      fTriggerParticle(0),
      fTriggerEta(0.9),     
+     fTriggerMultiplicity(0),
+     fTriggerMultiplicityEta(0),
+     fTriggerMultiplicityEtaMin(0),
+     fTriggerMultiplicityEtaMax(0),
+     fTriggerMultiplicityPtMin(0),  
      fCountMode(kCountAll),      
      fHeader(0),  
      fRL(0),      
@@ -883,6 +893,42 @@ Int_t  AliGenPythiaPlus::GenerateMB()
       }
     }
 
+    // Check for minimum multiplicity
+    if (fTriggerMultiplicity > 0) {
+      Int_t multiplicity = 0;
+      for (i = 0; i < np; i++) {
+	TParticle *  iparticle = (TParticle *) fParticles.At(i);
+
+	Int_t statusCode = iparticle->GetStatusCode();
+
+	// Initial state particle
+	if (statusCode != 1)
+	  continue;
+	// eta cut
+	if (fTriggerMultiplicityEta > 0 && TMath::Abs(iparticle->Eta()) > fTriggerMultiplicityEta)
+	  continue;
+	//multiplicity check for a given eta range
+	if ((fTriggerMultiplicityEtaMin != fTriggerMultiplicityEtaMax) && 
+	    (iparticle->Eta() < fTriggerMultiplicityEtaMin || iparticle->Eta() > fTriggerMultiplicityEtaMax))
+	  continue;
+	// pt cut
+	if (iparticle->Pt() < fTriggerMultiplicityPtMin) 
+	    continue;
+
+	TParticlePDG* pdgPart = iparticle->GetPDG();
+	if (pdgPart && pdgPart->Charge() == 0)
+	  continue;
+
+	++multiplicity;
+      }
+
+      if (multiplicity < fTriggerMultiplicity) {
+	delete [] pParent;
+	return 0;
+      }
+      Printf("Triggered on event with multiplicity of %d >= %d", multiplicity, fTriggerMultiplicity);
+    }
+
     if (fTriggerParticle) {
 	Bool_t triggered = kFALSE;
 	for (i = 0; i < np; i++) {

diff --git a/PYTHIA6/AliPythia6/AliGenPythiaPlus.h b/PYTHIA6/AliPythia6/AliGenPythiaPlus.h
@@ -160,6 +160,16 @@ class AliGenPythiaPlus : public AliGenMC
     //---------------------------------------------------------  
 
 
+    // Trigger on a minimum multiplicity
+    virtual void  SetTriggerChargedMultiplicity(Int_t multiplicity, Float_t etamax = 0, Float_t ptmin = -1.) 
+    {fTriggerMultiplicity = multiplicity; fTriggerMultiplicityEta = etamax; 
+      fTriggerMultiplicityPtMin = ptmin;}
+
+    // Trigger on a minimum multiplicity for a given eta range
+    virtual void  SetTriggerMultiplicityEtaRange(Int_t multiplicity, Float_t etamin = 0., Float_t etamax = 0., Float_t ptmin = -1.) 
+    {fTriggerMultiplicity = multiplicity; fTriggerMultiplicityEtaMin = etamin; fTriggerMultiplicityEtaMax = etamax; 
+      fTriggerMultiplicityPtMin = ptmin;}
+
     // Trigger on a single particle (not related to calorimeter trigger above)
     virtual void    SetTriggerParticle(Int_t particle = 0, Float_t etamax = 0.9) 
 	{fTriggerParticle = particle; fTriggerEta = etamax;}
@@ -310,6 +320,11 @@ class AliGenPythiaPlus : public AliGenMC
     Bool_t  fHFoff;                 // Flag for switching heafy flavor production off
     Int_t   fTriggerParticle;       // Trigger on this particle ...
     Float_t fTriggerEta;            // .. within |eta| < fTriggerEta
+    Int_t       fTriggerMultiplicity;       // Trigger on events with a minimum charged multiplicity
+    Float_t     fTriggerMultiplicityEta;    // in a given eta range
+    Float_t     fTriggerMultiplicityEtaMin;    // in a given eta min
+    Float_t     fTriggerMultiplicityEtaMax;    // in a given eta max
+    Float_t     fTriggerMultiplicityPtMin;  // above this pT 
     CountMode_t fCountMode;         // Options for counting when the event will be finished.     
     // fCountMode = kCountAll         --> All particles that end up in the
     //                                    stack are counted
@@ -354,7 +369,7 @@ class AliGenPythiaPlus : public AliGenMC
     AliGenPythiaPlus(const AliGenPythiaPlus &Pythia);
     AliGenPythiaPlus & operator=(const AliGenPythiaPlus & rhs);
 
-    ClassDef(AliGenPythiaPlus, 5)
+    ClassDef(AliGenPythiaPlus, 6)
 
 };
 #endif