]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - EVGEN/AliGenMC.cxx
Changes needed for MC production of J/psi from B with radiative decays
[u/mrichter/AliRoot.git] / EVGEN / AliGenMC.cxx
index ce15a232008afac680f5577927808859c4298996..fab6219b00cf767c2af9e0a3973eac57851771a7 100644 (file)
 // decay products and particle selection.
 // andreas.morsch@cern.ch
 
+#include <TClonesArray.h>
 #include <TMath.h>
 #include <TPDGCode.h>
 #include <TParticle.h>
+#include <TLorentzVector.h>
+#include <TVector3.h>
 
 #include "AliGenMC.h"
+#include "AliGenEventHeader.h"
+#include "AliRun.h"
+#include "AliGeometry.h"
+#include "AliDecayer.h"
 
- ClassImp(AliGenMC)
+ClassImp(AliGenMC)
 
 AliGenMC::AliGenMC()
-                 :AliGenerator()
+    :AliGenerator(),
+     fParticles("TParticle", 1000),
+     fParentSelect(8),
+     fChildSelect(8),
+     fCutOnChild(0),
+     fChildPtMin(0.),
+     fChildPtMax(1.e10),
+     fChildPMin(0.),
+     fChildPMax(1.e10),
+     fChildPhiMin(0.),
+     fChildPhiMax(2. * TMath::Pi()),
+     fChildThetaMin(0.),
+     fChildThetaMax(TMath::Pi()),
+     fChildYMin(-12.),
+     fChildYMax(12.),
+     fXingAngleX(0.),
+     fXingAngleY(0.),
+     fForceDecay(kAll),
+     fMaxLifeTime(1.e-15),
+     fDyBoost(0.),
+     fGeometryAcceptance(0),
+     fPdgCodeParticleforAcceptanceCut(0),
+     fNumberOfAcceptedParticles(0),
+     fNprimaries(0)
 {
 // Default Constructor
-    SetCutOnChild();
-    SetChildMomentumRange();
-    SetChildPtRange();
-    SetChildPhiRange();
-    SetChildThetaRange(); 
-    SetChildYRange(); 
-    SetMaximumLifetime();
-    SetGeometryAcceptance();
-    SetPdgCodeParticleforAcceptanceCut();
-    SetNumberOfAcceptedParticles();
-    SetTarget();
-    SetProjectile();
+  fAProjectile = 1;
+  fZProjectile = 1;
+  fATarget = 1;
+  fZTarget = 1;
+  fProjectile = "P";
+  fTarget = "P";
 }
 
 AliGenMC::AliGenMC(Int_t npart)
-                 :AliGenerator(npart)
+    :AliGenerator(npart),
+     fParticles("TParticle", 1000),
+     fParentSelect(8),
+     fChildSelect(8),
+     fCutOnChild(0),
+     fChildPtMin(0.),
+     fChildPtMax(1.e10),
+     fChildPMin(0.),
+     fChildPMax(1.e10),
+     fChildPhiMin(0.),
+     fChildPhiMax(2. * TMath::Pi()),
+     fChildThetaMin(0.),
+     fChildThetaMax(TMath::Pi()),
+     fChildYMin(-12.),
+     fChildYMax(12.),
+     fXingAngleX(0.),
+     fXingAngleY(0.),
+     fForceDecay(kAll),
+     fMaxLifeTime(1.e-15),
+     fDyBoost(0.),
+     fGeometryAcceptance(0),
+     fPdgCodeParticleforAcceptanceCut(0),
+     fNumberOfAcceptedParticles(0),
+     fNprimaries(0)
 {
 //  Constructor
-    SetCutOnChild();
-    SetChildMomentumRange();
-    SetChildPtRange();
-    SetChildPhiRange();
-    SetChildThetaRange();
-    SetChildYRange(); 
 // 
-    fParentSelect.Set(8);
-    fChildSelect.Set(8);
-    for (Int_t i=0; i<8; i++) fParentSelect[i]=fChildSelect[i]=0;
-    SetMaximumLifetime();
-    SetGeometryAcceptance();
-    SetPdgCodeParticleforAcceptanceCut();
-    SetNumberOfAcceptedParticles();
-    SetTarget();
-    SetProjectile();
-}
-
-AliGenMC::AliGenMC(const AliGenMC & mc)
-{
-// copy constructor
+  fAProjectile = 1;
+  fZProjectile = 1;
+  fATarget = 1;
+  fZTarget = 1;
+  fProjectile = "P";
+  fTarget = "P";
+  for (Int_t i=0; i<8; i++) fParentSelect[i]=fChildSelect[i]=0;
 }
 
 AliGenMC::~AliGenMC()
@@ -84,30 +118,71 @@ void AliGenMC::Init()
 //
 //  Initialization
     switch (fForceDecay) {
+    case kBSemiElectronic:
     case kSemiElectronic:
     case kDiElectron:
     case kBJpsiDiElectron:
     case kBPsiPrimeDiElectron:
+    case kElectronEM:
+    case kDiElectronEM:
        fChildSelect[0] = kElectron;    
        break;
+    case kHardMuons:   
+    case kBSemiMuonic:
     case kSemiMuonic:
     case kDiMuon:
+    case kJpsiDiMuon:
     case kBJpsiDiMuon:
     case kBPsiPrimeDiMuon:
     case kPiToMu:
     case kKaToMu:
+    case kWToMuon:
+    case kWToCharmToMuon:
+    case kZDiMuon:
+    case kZDiElectron:
        fChildSelect[0]=kMuonMinus;
        break;
+    case kWToCharm:
+       break;
     case kHadronicD:
+    case kHadronicDWithout4Bodies:
        fChildSelect[0]=kPiPlus;
        fChildSelect[1]=kKPlus;
        break;
     case kPhiKK:
        fChildSelect[0]=kKPlus;
-    case kOmega:       
+       break;
+    case kBJpsi:
+    case kBJpsiUndecayed:
+       fChildSelect[0]= 443;
+       break;
+   case kChiToJpsiGammaToMuonMuon:
+        fChildSelect[0]= 22;
+        fChildSelect[1]= 13;
+        break;
+    case kChiToJpsiGammaToElectronElectron:
+        fChildSelect[0]= 22;
+        fChildSelect[1]= 11;
+        break;
+    case kLambda:      
+       fChildSelect[0]= kProton;
+        fChildSelect[1]= 211;
+       break;
+    case kPsiPrimeJpsiDiElectron:
+        fChildSelect[0]= 211;
+        fChildSelect[1]= 11;
+       break;
+    case kGammaEM:
+        fChildSelect[0] = kGamma;      
+        break;
+    case kOmega:
     case kAll:
+    case kAllMuonic:
     case kNoDecay:
     case kNoDecayHeavy:
+    case kNoDecayBeauty:
+    case kNeutralPion:
+    case kBeautyUpgrade:
        break;
     }
 
@@ -139,17 +214,21 @@ Bool_t AliGenMC::ChildSelected(Int_t ip) const
     return kFALSE;
 }
 
-Bool_t AliGenMC::KinematicSelection(TParticle *particle, Int_t flag) const
+Bool_t AliGenMC::KinematicSelection(const TParticle *particle, Int_t flag) const
 {
 // Perform kinematic selection
-    Float_t pz    = particle->Pz();
-    Float_t  e    = particle->Energy();
-    Float_t pt    = particle->Pt();
-    Float_t p     = particle->P();
-    Float_t theta = particle->Theta();
-    Float_t mass  = particle->GetCalcMass();
-    Float_t mt2   = pt * pt + mass * mass;
-    Float_t phi   = particle->Phi();
+    Double_t pz    = particle->Pz();
+    Double_t pt    = particle->Pt();
+    Double_t p     = particle->P();
+    Double_t theta = particle->Theta();
+    Double_t mass  = particle->GetCalcMass();
+    Double_t mt2   = pt * pt + mass * mass;
+    Double_t phi   = particle->Phi();
+    Double_t e     = particle->Energy();
+    
+    if (e == 0.)     
+       e = TMath::Sqrt(p * p + mass * mass);
+
     
     Double_t y, y0;
 
@@ -244,24 +323,26 @@ Bool_t AliGenMC::KinematicSelection(TParticle *particle, Int_t flag) const
 
 Bool_t AliGenMC::CheckAcceptanceGeometry(Int_t np, TClonesArray* particles)
 {
-  Bool_t Check ;  // All fPdgCodeParticleforAcceptanceCut particles are in in the fGeometryAcceptance acceptance
-  Int_t NumberOfPdgCodeParticleforAcceptanceCut=0;
-  Int_t NumberOfAcceptedPdgCodeParticleforAcceptanceCut=0;
+// Check the geometrical acceptance for particle.
+
+  Bool_t check ;  
+  Int_t numberOfPdgCodeParticleforAcceptanceCut = 0;
+  Int_t numberOfAcceptedPdgCodeParticleforAcceptanceCut = 0;
   TParticle * particle;
   Int_t i;
-  for (i=0; i<np; i++) {
+  for (i = 0; i < np; i++) {
     particle =  (TParticle *) particles->At(i);
     if( TMath::Abs( particle->GetPdgCode() ) == TMath::Abs( fPdgCodeParticleforAcceptanceCut ) ) {
-      NumberOfPdgCodeParticleforAcceptanceCut++;
-      if (fGeometryAcceptance->Impact(particle)) NumberOfAcceptedPdgCodeParticleforAcceptanceCut++;
+      numberOfPdgCodeParticleforAcceptanceCut++;
+      if (fGeometryAcceptance->Impact(particle)) numberOfAcceptedPdgCodeParticleforAcceptanceCut++;
     }   
   }
-  if ( NumberOfAcceptedPdgCodeParticleforAcceptanceCut > (fNumberOfAcceptedParticles-1) )
-    Check = kTRUE;
+  if ( numberOfAcceptedPdgCodeParticleforAcceptanceCut > (fNumberOfAcceptedParticles-1) )
+    check = kTRUE;
   else
-    Check = kFALSE;
+    check = kFALSE;
 
-  return Check;
+  return check;
 }
 
 Int_t AliGenMC::CheckPDGCode(Int_t pdgcode) const
@@ -304,16 +385,16 @@ void AliGenMC::Boost()
 //
 
     Double_t beta  = TMath::TanH(fDyBoost);
-    Double_t gamma = 1./TMath::Sqrt(1.-beta*beta);
+    Double_t gamma = 1./TMath::Sqrt((1.-beta)*(1.+beta));
     Double_t gb    = gamma * beta;
 
-    //    printf("\n Boosting particles to lab frame %f %f %f", fDyBoost, beta, gamma);
+    printf("\n Boosting particles to lab frame %f %f %f", fDyBoost, beta, gamma);
     
     Int_t i;
-    Int_t np = fParticles->GetEntriesFast();
+    Int_t np = fParticles.GetEntriesFast();
     for (i = 0; i < np; i++) 
     {
-       TParticle* iparticle = (TParticle*) fParticles->At(i);
+       TParticle* iparticle = (TParticle*) fParticles.At(i);
 
        Double_t e   = iparticle->Energy();
        Double_t px  = iparticle->Px();
@@ -327,11 +408,53 @@ void AliGenMC::Boost()
     }
 }
 
-
-         
-AliGenMC& AliGenMC::operator=(const  AliGenMC& rhs)
+void AliGenMC::BeamCrossAngle()
 {
-// Assignment operator
-    return *this;
+  // Applies a boost in the y-direction in order to take into account the 
+  // beam crossing angle
+
+  Double_t thetaPr0, phiPr0, pyPr2, pzPr2;
+  TVector3 beta;
+  
+  thetaPr0 = fXingAngleY / 2.;
+  phiPr0 = 0;
+
+  // Momentum of the CMS system
+  pyPr2 = TMath::Sqrt(fEnergyCMS * fEnergyCMS/ 4 - 0.938 * 0.938) * TMath::Sin(thetaPr0); 
+  pzPr2 = TMath::Sqrt(fEnergyCMS * fEnergyCMS/ 4 - 0.938 * 0.938) * TMath::Cos(thetaPr0);
+
+  TLorentzVector proj1Vect, proj2Vect, projVect;
+  proj1Vect.SetPxPyPzE(0., pyPr2, pzPr2, fEnergyCMS/2);
+  proj2Vect.SetPxPyPzE(0., pyPr2,-pzPr2, fEnergyCMS/2);
+  projVect = proj1Vect + proj2Vect;
+  beta=(1. / projVect.E()) * (projVect.Vect());
+
+  Int_t i;
+  Int_t np = fParticles.GetEntriesFast();
+  for (i = 0; i < np; i++) 
+    {
+      TParticle* iparticle = (TParticle*) fParticles.At(i);
+
+      Double_t e   = iparticle->Energy();
+      Double_t px  = iparticle->Px();
+      Double_t py  = iparticle->Py();
+      Double_t pz  = iparticle->Pz();
+      
+      TLorentzVector partIn;
+      partIn.SetPxPyPzE(px,py,pz,e);
+      partIn.Boost(beta);
+      iparticle->SetMomentum(partIn.Px(),partIn.Py(),partIn.Pz(),partIn.E());
+    }
 }
 
+
+void AliGenMC::AddHeader(AliGenEventHeader* header)
+{
+    // Passes header either to the container or to gAlice
+    if (fContainer) {
+        header->SetName(fName);
+       fContainer->AddHeader(header);
+    } else {
+       gAlice->SetGenEventHeader(header);      
+    }
+}