]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - EVGEN/AliGenParam.cxx
Changes concerning the cocktail simulations used for heavy flavour v2 analyses.
[u/mrichter/AliRoot.git] / EVGEN / AliGenParam.cxx
index 32191ad86951433b920d27b227f437aed1edc86b..be599f95fc3b88b6136984c3c4049c947daca54e 100644 (file)
 // Decays are performed using Pythia.
 // andreas.morsch@cern.ch
 
-#include "AliGenParam.h"
-#include "AliDecayer.h"
-#include "AliGenMUONlib.h"
-#include "AliRun.h"
-#include <TParticle.h>
-#include <TParticlePDG.h>
+#include <TCanvas.h>
+#include <TClonesArray.h>
 #include <TDatabasePDG.h>
+#include <TF1.h>
+#include <TH1F.h>
 #include <TLorentzVector.h>
+#include <TMath.h>
+#include <TParticle.h>
+#include <TParticlePDG.h>
+#include <TROOT.h>
+#include <TVirtualMC.h>
 
-#include <TF1.h>
-#include <TCanvas.h>
-#include <TH1.h>
+#include "AliDecayer.h"
+#include "AliGenMUONlib.h"
+#include "AliGenParam.h"
+#include "AliMC.h"
+#include "AliRun.h"
+#include "AliGenEventHeader.h"
 
 ClassImp(AliGenParam)
 
 //------------------------------------------------------------
 
-  //Begin_Html
-  /*
+//Begin_Html
+/*
     <img src="picts/AliGenParam.gif">
-  */
-  //End_Html
+*/
+//End_Html
 
-//____________________________________________________________
 //____________________________________________________________
 AliGenParam::AliGenParam()
+: fPtParaFunc(0),
+       fYParaFunc(0),
+       fIpParaFunc(0),
+  fV2ParaFunc(0),
+       fPtPara(0),
+       fYPara(0),
+  fV2Para(0),
+  fdNdPhi(0),
+       fParam(0),
+       fdNdy0(0.),
+       fYWgt(0.),
+       fPtWgt(0.),
+       fBias(0.),
+       fTrials(0),
+       fDeltaPt(0.01),
+       fSelectAll(kFALSE),
+  fDecayer(0),
+  fForceConv(kFALSE)
 {
-// Deafault constructor
-    fPtPara = 0;
-    fYPara  = 0;
-    fParam  = 0;
-    fAnalog = kAnalog;
-    SetDeltaPt();
-    fDecayer = 0;
-
-
+  // Default constructor
 }
-
-AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library,  Int_t param, char* tname):AliGenMC(npart)
+//____________________________________________________________
+AliGenParam::AliGenParam(Int_t npart, const AliGenLib * Library,  Int_t param, const char* tname)
+    :AliGenMC(npart),
+     fPtParaFunc(Library->GetPt(param, tname)),
+     fYParaFunc (Library->GetY (param, tname)),
+     fIpParaFunc(Library->GetIp(param, tname)),
+   fV2ParaFunc(Library->GetV2(param, tname)),
+     fPtPara(0),
+     fYPara(0),
+   fV2Para(0),
+   fdNdPhi(0),
+     fParam(param),
+     fdNdy0(0.),
+     fYWgt(0.),
+     fPtWgt(0.),
+     fBias(0.),
+     fTrials(0),
+     fDeltaPt(0.01),
+     fSelectAll(kFALSE),
+   fDecayer(0),
+   fForceConv(kFALSE)
 {
-// Constructor using number of particles parameterisation id and library
+  // Constructor using number of particles parameterisation id and library
     fName = "Param";
     fTitle= "Particle Generator using pT and y parameterisation";
-    
-    fPtParaFunc = Library->GetPt(param, tname);
-    fYParaFunc  = Library->GetY (param, tname);
-    fIpParaFunc = Library->GetIp(param, tname);
-    
-    fPtPara = 0;
-    fYPara  = 0;
-    fParam  = param;
     fAnalog = kAnalog;
     SetForceDecay();
-    SetDeltaPt(); 
 }
-
 //____________________________________________________________
-
-AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
+AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char* name):
+    AliGenMC(npart),
+    fPtParaFunc(0),
+    fYParaFunc (0),
+    fIpParaFunc(0),
+  fV2ParaFunc(0),
+    fPtPara(0),
+    fYPara(0),
+  fV2Para(0),
+  fdNdPhi(0),
+    fParam(param),
+    fdNdy0(0.),
+    fYWgt(0.),
+    fPtWgt(0.),
+    fBias(0.),
+    fTrials(0),
+    fDeltaPt(0.01),
+    fSelectAll(kFALSE),
+  fDecayer(0),
+  fForceConv(kFALSE)
 {
-// Constructor using parameterisation id and number of particles
-//
-    fName = "Param";
+  // Constructor using parameterisation id and number of particles
+  //
+    fName = name;
     fTitle= "Particle Generator using pT and y parameterisation";
       
     AliGenLib* pLibrary = new AliGenMUONlib();
     fPtParaFunc = pLibrary->GetPt(param, tname);
     fYParaFunc  = pLibrary->GetY (param, tname);
     fIpParaFunc = pLibrary->GetIp(param, tname);
+  fV2ParaFunc = pLibrary->GetV2(param, tname);
     
-    fPtPara = 0;
-    fYPara  = 0;
-    fParam  = param;
     fAnalog = kAnalog;
     fChildSelect.Set(5);
     for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
@@ -104,27 +143,40 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
     SetChildPtRange();
     SetChildPhiRange();
     SetChildThetaRange(); 
-    SetDeltaPt(); 
 }
+//____________________________________________________________
 
 AliGenParam::AliGenParam(Int_t npart, Int_t param,
-                         Double_t (*PtPara) (Double_t*, Double_t*),
-                         Double_t (*YPara ) (Double_t* ,Double_t*),
+                         Double_t (*PtPara) (const Double_t*, const Double_t*),
+                         Double_t (*YPara ) (const Double_t* ,const Double_t*),
+                         Double_t (*V2Para) (const Double_t* ,const Double_t*),
                         Int_t    (*IpPara) (TRandom *))                 
-    :AliGenMC(npart)
+    :AliGenMC(npart),
+     
+     fPtParaFunc(PtPara),
+     fYParaFunc(YPara),
+     fIpParaFunc(IpPara),
+   fV2ParaFunc(V2Para),
+     fPtPara(0),
+     fYPara(0),
+   fV2Para(0),
+   fdNdPhi(0),
+     fParam(param),
+     fdNdy0(0.),
+     fYWgt(0.),
+     fPtWgt(0.),
+     fBias(0.),
+     fTrials(0),
+     fDeltaPt(0.01),
+     fSelectAll(kFALSE),
+  fDecayer(0),
+  fForceConv(kFALSE)
 {
-// Constructor
-// Gines Martinez 1/10/99 
+  // Constructor
+  // Gines Martinez 1/10/99 
     fName = "Param";
     fTitle= "Particle Generator using pT and y parameterisation";
 
-    fPtParaFunc = PtPara; 
-    fYParaFunc  = YPara;  
-    fIpParaFunc = IpPara;
-//  
-    fPtPara = 0;
-    fYPara  = 0;
-    fParam  = param;
     fAnalog = kAnalog;
     fChildSelect.Set(5);
     for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
@@ -134,29 +186,136 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param,
     SetChildPtRange();
     SetChildPhiRange();
     SetChildThetaRange();  
-    SetDeltaPt();
-}
-
-
-AliGenParam::AliGenParam(const AliGenParam & Param)
-    :AliGenMC(Param)
-{
-// Copy constructor
-    Param.Copy(*this);
 }
 
 //____________________________________________________________
 AliGenParam::~AliGenParam()
 {
-// Destructor
+  // Destructor
     delete  fPtPara;
     delete  fYPara;
+  delete  fV2Para;
+  delete  fdNdPhi;
+}
+
+//-------------------------------------------------------------------
+TVector3 AliGenParam::OrthogonalVector(TVector3 &inVec){
+  double abc[]={inVec.x(), inVec.y(), inVec.z()}; 
+  double xyz[]={1,1,1};
+  int solvDim=0;
+  double tmp=abc[0];
+  for(int i=0; i<3; i++)
+    if(abs(abc[i])>tmp){
+      solvDim=i;
+      tmp=abs(abc[i]);
+    }
+  xyz[solvDim]=(-abc[(1+solvDim)%3]-abc[(2+solvDim)%3])/abc[(0+solvDim)%3];
+  
+  TVector3 res(xyz[0],xyz[1],xyz[2]);
+  return res;
+}
+
+double AliGenParam::ScreenFunc1(double d){
+  if(d>1)
+    return 21.12-4.184*log(d+0.952);
+  else
+    return 20.867-3.242*d+0.652*d*d;
+}
+
+double AliGenParam::ScreenFunc2(double d){
+  if(d>1)
+    return 21.12-4.184*log(d+0.952);
+  else
+    return 20.209-1.93*d-0.086*d*d;
+}
+
+double AliGenParam::EnergyFraction(double Z, double E){
+  double e0=0.000511/E;
+  double aZ=Z/137.036;
+  double dmin=ScreenVar(Z,e0,0.5);
+  double fcZ=(aZ*aZ)*(1/(1+aZ*aZ)+0.20206-0.0368*aZ*aZ+0.0083*aZ*aZ*aZ);
+  double Fz=8*log(Z)/3;
+  if(E>0.05)
+    Fz+=8*fcZ;
+  double dmax=exp((42.24-Fz)/8.368)-0.952;
+  if(!(dmax>dmin))
+    return fRandom->Uniform(e0,0.5);
+
+  double e1=0.5-0.5*sqrt(1-dmin/dmax);
+  double emin=TMath::Max(e0,e1);
+  
+  double normval=1/(0.5*(ScreenFunc1(dmin)-0.5*Fz)+0.1666667*(ScreenFunc2(dmin)-0.5*Fz));
+  while(true){
+    double y=fRandom->Uniform(emin,1);
+    double eps=y*(0.38453+y*(0.10234+y*(0.026072+y*(0.014367-0.027313*y)))); //inverse to the enveloping cumulative probability distribution
+    double val=fRandom->Uniform(0,2.12*(eps*eps-eps)+1.53); //enveloping probability density
+    double d=ScreenVar(Z,e0,eps);
+    double bh=((eps*eps)+(1-eps)*(1-eps))*(ScreenFunc1(d)-0.5*Fz)+0.6666667*eps*(1-eps)*(ScreenFunc2(d)-0.5*Fz);
+    bh*=normval;
+    if(val<bh)
+      return eps;
+  }
+}
+
+double AliGenParam::PolarAngle(double E){
+  float rand[3];
+  AliRndm rndm;
+  rndm.Rndm(rand,3);
+  double u=-8*log(rand[1]*rand[2])/5;
+  if(!(rand[0]<9.0/36))
+    u/=3;
+  return u*0.000511/E;
+}
+
+Int_t AliGenParam::ForceGammaConversion(TClonesArray *particles, Int_t nPart)
+{
+  //based on: http://geant4.cern.ch/G4UsersDocuments/UsersGuides/PhysicsReferenceManual/html/node27.html
+  //     and: http://geant4.cern.ch/G4UsersDocuments/UsersGuides/PhysicsReferenceManual/html/node58.html
+  Int_t nPartNew=nPart;
+  for(int iPart=0; iPart<nPart; iPart++){      
+    TParticle *gamma = (TParticle *) particles->At(iPart);
+    if(gamma->GetPdgCode()!=22) continue;
+
+    TVector3 gammaV3(gamma->Px(),gamma->Py(),gamma->Pz());
+    Float_t az=fRandom->Uniform(TMath::Pi()*2);
+    double frac=EnergyFraction(1,gamma->Energy());
+    double Ee1=frac*gamma->Energy();
+    double Ee2=(1-frac)*gamma->Energy();
+    double Pe1=Ee1;//sqrt(Ee1*Ee1-0.000511*0.000511);
+    double Pe2=Ee2;//sqrt(Ee2*Ee2-0.000511*0.000511);
+    
+    TVector3 rotAxis(OrthogonalVector(gammaV3));
+    rotAxis.Rotate(az,gammaV3);
+    TVector3 e1V3(gammaV3);
+    e1V3.Rotate(PolarAngle(Ee1),rotAxis);
+    e1V3=e1V3.Unit();
+    e1V3*=Pe1;
+    TVector3 e2V3(gammaV3);
+    e2V3.Rotate(-PolarAngle(Ee2),rotAxis);
+    e2V3=e2V3.Unit();
+    e2V3*=Pe2;
+    // gamma = new TParticle(*gamma);
+    // particles->RemoveAt(iPart);
+    gamma->SetFirstDaughter(nPartNew+1);
+    gamma->SetLastDaughter(nPartNew+2);
+    // new((*particles)[iPart]) TParticle(*gamma);
+    // delete gamma;
+
+    TLorentzVector vtx;
+    gamma->ProductionVertex(vtx);
+    new((*particles)[nPartNew]) TParticle(11, gamma->GetStatusCode(), iPart+1, -1, 0, 0, TLorentzVector(e1V3,Ee1), vtx);
+    nPartNew++;
+    new((*particles)[nPartNew]) TParticle(-11, gamma->GetStatusCode(), iPart+1, -1, 0, 0, TLorentzVector(e2V3,Ee2), vtx);
+    nPartNew++;
+  }
+  // particles->Compress();
+  return particles->GetEntriesFast();
 }
 
 //____________________________________________________________
 void AliGenParam::Init()
 {
-// Initialisation
+  // Initialisation
 
     if (gMC) fDecayer = gMC->GetDecayer();
   //Begin_Html
@@ -164,29 +323,59 @@ void AliGenParam::Init()
     <img src="picts/AliGenParam.gif">
   */
   //End_Html
-    fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
-//  Set representation precision to 10 MeV
-    Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
+    char name[256];
+    snprintf(name, 256, "pt-parameterisation for %s", GetName());
+    
+    if (fPtPara) fPtPara->Delete();
+    fPtPara = new TF1(name, fPtParaFunc, fPtMin, fPtMax,0);
+    gROOT->GetListOfFunctions()->Remove(fPtPara);
+  //  Set representation precision to 10 MeV
+    Int_t npx= Int_t((fPtMax - fPtMin) / fDeltaPt);
     
     fPtPara->SetNpx(npx);
+
+    snprintf(name, 256, "y-parameterisation  for %s", GetName());
+    if (fYPara) fYPara->Delete();
+    fYPara  = new TF1(name, fYParaFunc, fYMin, fYMax, 0);
+    gROOT->GetListOfFunctions()->Remove(fYPara);
+
+  snprintf(name, 256, "v2-parameterisation for %s", GetName());
+  if (fV2Para) fV2Para->Delete();
+  fV2Para  = new TF1(name, fV2ParaFunc, fPtMin, fPtMax, 0);
+  // fV2Para  = new TF1(name, "2*[0]/(1+TMath::Exp([1]*([2]-x)))-[0]", fPtMin, fPtMax);
+  // fV2Para->SetParameter(0, 0.236910);
+  // fV2Para->SetParameter(1, 1.71122);
+  // fV2Para->SetParameter(2, 0.0827617);
+  //gROOT->GetListOfFunctions()->Remove(fV2Para);  //TR: necessary?
+    
+  snprintf(name, 256, "dNdPhi for %s", GetName());
+  if (fdNdPhi) fdNdPhi->Delete();
+  fdNdPhi  = new TF1(name, "1+2*[0]*TMath::Cos(2*(x-[1]))", fPhiMin, fPhiMax);
+  //gROOT->GetListOfFunctions()->Remove(fdNdPhi);  //TR: necessary?
     
-    fYPara  = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
-    TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
-    TF1* yPara  = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
+    snprintf(name, 256, "pt-for-%s", GetName());
+    TF1 ptPara(name ,fPtParaFunc, 0, 15, 0);
+    snprintf(name, 256, "y-for-%s", GetName());
+    TF1 yPara(name, fYParaFunc, -6, 6, 0);
 
-//
-// dN/dy| y=0
+  //
+  // dN/dy| y=0
     Double_t y1=0;
     Double_t y2=0;
     
     fdNdy0=fYParaFunc(&y1,&y2);
-//
-// Integral over generation region
-    Float_t intYS  = yPara ->Integral(fYMin, fYMax);
-    Float_t intPt0 = ptPara->Integral(0,15);
-    Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
-    Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
+  //
+  // Integral over generation region
+#if ROOT_VERSION_CODE < ROOT_VERSION(5,99,0)
+    Float_t intYS  = yPara.Integral(fYMin, fYMax,(Double_t*) 0x0,1.e-6);
+    Float_t intPt0 = ptPara.Integral(0,15,(Double_t *) 0x0,1.e-6);
+    Float_t intPtS = ptPara.Integral(fPtMin,fPtMax,(Double_t*) 0x0,1.e-6);
+#else
+    Float_t intYS  = yPara.Integral(fYMin, fYMax,1.e-6);
+    Float_t intPt0 = ptPara.Integral(0,15,1.e-6);
+    Float_t intPtS = ptPara.Integral(fPtMin,fPtMax,1.e-6);
+#endif
+  Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();    //TR: should probably be done differently in case of anisotropic phi...
     if (fAnalog == kAnalog) {
        fYWgt  = intYS/fdNdy0;
        fPtWgt = intPtS/intPt0;
@@ -196,34 +385,45 @@ void AliGenParam::Init()
        fPtWgt = (fPtMax-fPtMin)/intPt0;
        fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
     }
-//
-// particle decay related initialization
+  //
+  // particle decay related initialization
     fDecayer->SetForceDecay(fForceDecay);
     fDecayer->Init();
 
-//
+  //
     AliGenMC::Init();
 }
 
 //____________________________________________________________
 void AliGenParam::Generate()
 {
-//
-// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
-// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and 
-// antineutrons in the the desired theta, phi and momentum windows; 
-// Gaussian smearing on the vertex is done if selected. 
-// The decay of heavy mesons is done using lujet, 
-//    and the childern particle are tracked by GEANT
-// However, light mesons are directly tracked by GEANT 
-// setting fForceDecay = nodecay (SetForceDecay(nodecay)) 
-//
-//
-//  Reinitialize decayer
-    fDecayer->Init();
-//
+  // 
+  // Generate 1 event (see Generate(Int_t ntimes) for details
+  //
+  GenerateN(1);
+}
+//____________________________________________________________
+void AliGenParam::GenerateN(Int_t ntimes)
+{
+  //
+  // Generate ntimes*'npart' light and heavy mesons (J/Psi, upsilon or phi, Pion,
+  // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and 
+  // antineutrons in the the desired theta, phi and momentum windows; 
+  // Gaussian smearing on the vertex is done if selected. 
+  // The decay of heavy mesons is done using lujet, 
+  //    and the childern particle are tracked by GEANT
+  // However, light mesons are directly tracked by GEANT 
+  // setting fForceDecay = nodecay (SetForceDecay(nodecay)) 
+  //
+  //
+  //  Reinitialize decayer
+  fDecayer->SetForceDecay(fForceDecay);
+  fDecayer->Init();
+
+  //
   Float_t polar[3]= {0,0,0};  // Polarisation of the parent particle (for GEANT tracking)
   Float_t origin0[3];         // Origin of the generated parent particle (for GEANT tracking)
+  Float_t time0;              // Time0 of the generated parent particle
   Float_t pt, pl, ptot;       // Transverse, logitudinal and total momenta of the parent particle
   Float_t phi, theta;         // Phi and theta spherical angles of the parent particle momentum
   Float_t p[3], pc[3], 
@@ -240,34 +440,36 @@ void AliGenParam::Generate()
   //
   Float_t random[6];
  
-// Calculating vertex position per event
+  // Calculating vertex position per event
   for (j=0;j<3;j++) origin0[j]=fOrigin[j];
+  time0 = fTimeOrigin;
   if(fVertexSmear==kPerEvent) {
       Vertex();
       for (j=0;j<3;j++) origin0[j]=fVertex[j];
+      time0 = fTime;
   }
   
   Int_t ipa=0;
   
-// Generating fNpart particles
-  while (ipa<fNpart) {
+  // Generating fNpart particles
+  fNprimaries = 0;
+  
+  Int_t nGen = fNpart*ntimes;
+  while (ipa<nGen) {
       while(1) {
-//
-// particle type
+      //
+      // particle type 
          Int_t iPart = fIpParaFunc(fRandom);
          fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;          
          TParticlePDG *particle = pDataBase->GetParticle(iPart);
          Float_t am = particle->Mass();
          
          Rndm(random,2);
-//
-// phi
-         phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
-//
-// y
+      //
+      // y
          ty = TMath::TanH(fYPara->GetRandom());
-//
-// pT
+      //
+      // pT
          if (fAnalog == kAnalog) {
              pt=fPtPara->GetRandom();
              wgtp=fParentWeight;
@@ -284,15 +486,25 @@ void AliGenParam::Generate()
              Fatal("AliGenParam", 
                    "Division by 0: Please check you rapidity range !");
          }
+      //
+      // phi
+         //      if(!ipa)
+         //phi=fEvPlane; //align first particle of each event with event plane
+         //else{
+       double v2 = fV2Para->Eval(pt);
+       fdNdPhi->SetParameter(0,v2);
+       fdNdPhi->SetParameter(1,fEvPlane);
+       phi=fdNdPhi->GetRandom();
+       //     }
          
-         pl=xmt*ty/sqrt(1.-ty*ty);
+         pl=xmt*ty/sqrt((1.-ty)*(1.+ty));
          theta=TMath::ATan2(pt,pl);
-// Cut on theta
+      // Cut on theta
          if(theta<fThetaMin || theta>fThetaMax) continue;
          ptot=TMath::Sqrt(pt*pt+pl*pl);
-// Cut on momentum
+      // Cut on momentum
          if(ptot<fPMin || ptot>fPMax) continue;
-//
+      //
          p[0]=pt*TMath::Cos(phi);
          p[1]=pt*TMath::Sin(phi);
          p[2]=pl;
@@ -303,25 +515,39 @@ void AliGenParam::Generate()
                      fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
                      TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
              }
+             Rndm(random,2);
+             time0 = fTimeOrigin + fOsigma[2]/TMath::Ccgs()*
+               TMath::Cos(2*random[0]*TMath::Pi())*
+               TMath::Sqrt(-2*TMath::Log(random[1]));
          }
          
-// Looking at fForceDecay : 
-// if fForceDecay != none Primary particle decays using 
-// AliPythia and children are tracked by GEANT
-//
-// if fForceDecay == none Primary particle is tracked by GEANT 
-// (In the latest, make sure that GEANT actually does all the decays you want)   
-//
+      // Looking at fForceDecay : 
+      // if fForceDecay != none Primary particle decays using 
+      // AliPythia and children are tracked by GEANT
+      //
+      // if fForceDecay == none Primary particle is tracked by GEANT 
+      // (In the latest, make sure that GEANT actually does all the decays you want)     
+      //
+         Bool_t decayed = kFALSE;
+         
 
          if (fForceDecay != kNoDecay) {
-// Using lujet to decay particle
+       // Using lujet to decay particle
              Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
              TLorentzVector pmom(p[0], p[1], p[2], energy);
              fDecayer->Decay(iPart,&pmom);
-//
-// select decay particles
+       //
+       // select decay particles
              Int_t np=fDecayer->ImportParticles(particles);
 
+       if(fForceConv) np=ForceGammaConversion(particles,np);
+
+       // for(int iPart=0; iPart<np; iPart++){
+       //   TParticle *gamma = (TParticle *) particles->At(iPart);
+       //   printf("%i %i:", iPart, gamma->GetPdgCode());
+       //   printf("%i %i %i|",gamma->GetFirstMother(),gamma->GetFirstDaughter(),gamma->GetLastDaughter());
+       // }
+
              //  Selecting  GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
              if (fGeometryAcceptance) 
                if (!CheckAcceptanceGeometry(np,particles)) continue;
@@ -338,14 +564,15 @@ void AliGenParam::Generate()
              }
              
              if (np >1) {
-                 TParticle* iparticle =  (TParticle *) particles->At(0);
+                 decayed = kTRUE;
+                 TParticle* iparticle =  0;
                  Int_t ipF, ipL;
                  for (i = 1; i<np ; i++) {
                      trackIt[i] = 1;
                      iparticle = (TParticle *) particles->At(i);
                      Int_t kf = iparticle->GetPdgCode();
                      Int_t ks = iparticle->GetStatusCode();
-// flagged particle
+           // flagged particle
 
                      if (pFlag[i] == 1) {
                          ipF = iparticle->GetFirstDaughter();
@@ -354,14 +581,14 @@ void AliGenParam::Generate()
                          continue;
                      }
 
-// flag decay products of particles with long life-time (c tau > .3 mum)                     
+           // flag decay products of particles with long life-time (c tau > .3 mum)                  
                      
                      if (ks != 1) { 
-//                       TParticlePDG *particle = pDataBase->GetParticle(kf);
+             //                          TParticlePDG *particle = pDataBase->GetParticle(kf);
                          
                          Double_t lifeTime = fDecayer->GetLifetime(kf);
-//                       Double_t mass     = particle->Mass();
-//                       Double_t width    = particle->Width();
+             //                          Double_t mass     = particle->Mass();
+             //                          Double_t width    = particle->Width();
                          if (lifeTime > (Double_t) fMaxLifeTime) {
                              ipF = iparticle->GetFirstDaughter();
                              ipL = iparticle->GetLastDaughter();       
@@ -371,10 +598,10 @@ void AliGenParam::Generate()
                              pSelected[i]   = 1;
                          }
                      } // ks==1 ?
-//
-// children
+           //
+           // children
                      
-                     if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
+                     if ((ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll || fSelectAll) && trackIt[i])
                      {
                          if (fCutOnChild) {
                              pc[0]=iparticle->Px();
@@ -399,38 +626,44 @@ void AliGenParam::Generate()
              Int_t iparent;
              if ((fCutOnChild && ncsel >0) || !fCutOnChild){
                  ipa++;
-//
-// Parent
-                 PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
+         //
+         // Parent
+                 
+                 
+                 PushTrack(0, -1, iPart, p, origin0, polar, time0, kPPrimary, nt, wgtp, ((decayed)? 11 : 1));
                  pParent[0] = nt;
                  KeepTrack(nt); 
-//
-// Decay Products
-//               
+                 fNprimaries++;
+                 
+         //
+         // Decay Products
+         //              
                  for (i = 1; i < np; i++) {
                      if (pSelected[i]) {
                          TParticle* iparticle = (TParticle *) particles->At(i);
-                         Int_t kf  = iparticle->GetPdgCode();
-                         Int_t ipa = iparticle->GetFirstMother()-1;
+                         Int_t kf   = iparticle->GetPdgCode();
+                         Int_t ksc  = iparticle->GetStatusCode();
+                         Int_t jpa  = iparticle->GetFirstMother()-1;
                          
-                         och[0] = origin0[0]+iparticle->Vx()/10;
-                         och[1] = origin0[1]+iparticle->Vy()/10;
-                         och[2] = origin0[2]+iparticle->Vz()/10;
+                         och[0] = origin0[0]+iparticle->Vx();
+                         och[1] = origin0[1]+iparticle->Vy();
+                         och[2] = origin0[2]+iparticle->Vz();
                          pc[0]  = iparticle->Px();
                          pc[1]  = iparticle->Py();
                          pc[2]  = iparticle->Pz();
                          
-                         if (ipa > -1) {
-                             iparent = pParent[ipa];
+                         if (jpa > -1) {
+                             iparent = pParent[jpa];
                          } else {
                              iparent = -1;
                          }
                         
-                         PushTrack(fTrackIt*trackIt[i], iparent, kf,
+                         PushTrack(fTrackIt * trackIt[i], iparent, kf,
                                           pc, och, polar,
-                                          0, kPDecay, nt, wgtch);
+                                          time0 + iparticle->T(), kPDecay, nt, wgtch, ksc);
                          pParent[i] = nt;
                          KeepTrack(nt); 
+                         fNprimaries++;
                      } // Selected
                  } // Particle loop 
              }  // Decays by Lujet
@@ -442,17 +675,46 @@ void AliGenParam::Generate()
          } // kinematic selection
          else  // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
          {
-           gAlice->
-               PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
+           gAlice->GetMCApp()->
+               PushTrack(fTrackIt,-1,iPart,p,origin0,polar,time0,kPPrimary,nt,wgtp, 1);
             ipa++; 
+           fNprimaries++;
          }
          break;
     } // while
   } // event loop
+  
   SetHighWaterMark(nt);
+
+  AliGenEventHeader* header = new AliGenEventHeader("PARAM");
+  header->SetPrimaryVertex(fVertex);
+  header->SetInteractionTime(fTime);
+  header->SetNProduced(fNprimaries);
+  AddHeader(header);
 }
+//____________________________________________________________________________________
+Float_t AliGenParam::GetRelativeArea(Float_t ptMin, Float_t ptMax, Float_t yMin, Float_t yMax, Float_t phiMin, Float_t phiMax)
+{
+  //
+  // Normalisation for selected kinematic region
+  //
+#if ROOT_VERSION_CODE < ROOT_VERSION(5,99,0)
+  Float_t ratio =  
+    fPtPara->Integral(ptMin,ptMax,(Double_t *)0,1.e-6) / fPtPara->Integral( fPtPara->GetXmin(), fPtPara->GetXmax(),(Double_t *)0,1.e-6) *
+    fYPara->Integral(yMin,yMax,(Double_t *)0,1.e-6)/fYPara->Integral(fYPara->GetXmin(),fYPara->GetXmax(),(Double_t *)0,1.e-6)   *
+    (phiMax-phiMin)/360.;
+#else
+  Float_t ratio =  
+    fPtPara->Integral(ptMin,ptMax,1.e-6) / fPtPara->Integral( fPtPara->GetXmin(), fPtPara->GetXmax(),1.e-6) *
+    fYPara->Integral(yMin,yMax,1.e-6)/fYPara->Integral(fYPara->GetXmin(),fYPara->GetXmax(),1.e-6)   *
+    (phiMax-phiMin)/360.;
+#endif
+  return TMath::Abs(ratio);
+}
+
+//____________________________________________________________________________________
 
-void AliGenParam::Draw()
+void AliGenParam::Draw( const char * /*opt*/)
 {
     //
     // Draw the pT and y Distributions
@@ -467,12 +729,6 @@ void AliGenParam::Draw()
      fYPara->GetHistogram()->SetXTitle("y");     
 }
 
-AliGenParam& AliGenParam::operator=(const  AliGenParam& rhs)
-{
-// Assignment operator
-    rhs.Copy(*this);
-    return *this;
-}