http://savannah.cern.ch/bugs/?103960

A. Hansen

EVGEN/AliGenTunedOnPbPb.cxx

@@ -141,8 +141,10 @@ void AliGenTunedOnPbPb::Generate()
   Float_t psi = gRandom->Rndm()*TMath::Pi();
   fgEventplane = psi;
   Float_t psi3 = gRandom->Rndm()*TMath::Pi()*2/3;
+  Float_t psi4 = gRandom->Rndm()*TMath::Pi()*2/4;
   fgV2->SetParameter(1,psi);
   fgV2->SetParameter(3,psi3);
+  fgV2->SetParameter(4,psi4);
 
   Int_t npart = 0;
 
@@ -212,6 +214,7 @@ void AliGenTunedOnPbPb::Generate()
     header->SetCentrality(centrality);
     header->SetPsi2(psi);
     header->SetPsi3(psi3);
+    header->SetPsi4(psi4);
     gAlice->SetGenEventHeader(header); 
 }
 
@@ -235,7 +238,7 @@ TH1F *AliGenTunedOnPbPb::GetMultVsCentrality(Int_t species){
 //_____________________________________________________________________________
 void AliGenTunedOnPbPb::SetParameters(Float_t centrality){
 
-  if(!fgV2) fgV2 = new TF1("fv2Par","TMath::Max(0.,(1 + 2*[0]*cos(2*(x-[1])) + 2*[0]*[2]*cos(3*(x-[3]))))",-TMath::Pi(),TMath::Pi());
+  if(!fgV2) fgV2 = new TF1("fv2Par","TMath::Max(0.,(1 + 2*[0]*cos(2*(x-[1])) + 2*[0]*[2]*cos(3*(x-[3])) + [0]*[2]*cos(4*(x-[4]))))",-TMath::Pi(),TMath::Pi()); // v4 is approx. 0.5*v3
 
   Float_t fr[9] = {0.,0.,0.,0.,0.,0.,0.,0.,0.};
 

STEER/STEERBase/AliGenEventHeaderTunedPbPb.cxx

@@ -20,7 +20,7 @@
 // Stores as a minimum the date, run number, event number,
 // number of particles produced  
 // and the impact parameter.
-// + Psi_2 Psi_3
+// + Psi_2 Psi_3 Psi4
 // Author: [email protected]
 //---------------------------------------------------------------------
 
@@ -33,7 +33,8 @@ AliGenEventHeaderTunedPbPb::AliGenEventHeaderTunedPbPb():
   AliGenEventHeader(),
   fCentrality(0.),
   fPsi2(0.),
-  fPsi3(0.)
+  fPsi3(0.),
+  fPsi4(0.)
 {
   //
   // Constructor
@@ -45,7 +46,8 @@ AliGenEventHeaderTunedPbPb::AliGenEventHeaderTunedPbPb(const char * name):
   AliGenEventHeader(name),
   fCentrality(0.),
   fPsi2(0.),
-  fPsi3(0.)
+  fPsi3(0.),
+  fPsi4(0.)
 {
   //
   // Constructor

STEER/STEERBase/AliGenEventHeaderTunedPbPb.h

@@ -25,16 +25,19 @@ class AliGenEventHeaderTunedPbPb : public AliGenEventHeader
   Float_t GetCentrality() const {return fCentrality;};
   Float_t GetPsi2() const {return fPsi2;};
   Float_t GetPsi3() const {return fPsi3;};
+  Float_t GetPsi4() const {return fPsi4;};
   // Setters
   void SetCentrality(Float_t centrality){fCentrality = centrality;};
   void SetPsi2(Float_t psi){fPsi2 = psi;};
   void SetPsi3(Float_t psi){fPsi3 = psi;};
+  void SetPsi4(Float_t psi){fPsi4 = psi;};
 
 protected:
   Float_t fCentrality;// centrality
   Float_t fPsi2;     // psi_2 EP
   Float_t fPsi3;     // psi_3 EP
-  ClassDef(AliGenEventHeaderTunedPbPb, 1)        // Event header for primary event
+  Float_t fPsi4;     // psi_4 EP
+  ClassDef(AliGenEventHeaderTunedPbPb, 2)        // Event header for primary event
 };
 
 #endif