newly implemented model for slow nucleon production
[u/mrichter/AliRoot.git] / EVGEN / AliGenParam.cxx
index 59d117e..717dae0 100644 (file)
@@ -44,19 +44,22 @@ ClassImp(AliGenParam)
 
 //------------------------------------------------------------
 
-  //Begin_Html
-  /*
+//Begin_Html
+/*
     <img src="picts/AliGenParam.gif">
-  */
-  //End_Html
+*/
+//End_Html
 
 //____________________________________________________________
-    AliGenParam::AliGenParam():
-       fPtParaFunc(0),
+AliGenParam::AliGenParam()
+: fPtParaFunc(0),
        fYParaFunc(0),
        fIpParaFunc(0),
+  fV2ParaFunc(0),
        fPtPara(0),
        fYPara(0),
+  fV2Para(0),
+  fdNdPhi(0),
        fParam(0),
        fdNdy0(0.),
        fYWgt(0.),
@@ -64,18 +67,22 @@ ClassImp(AliGenParam)
        fBias(0.),
        fTrials(0),
        fDeltaPt(0.01),
+       fSelectAll(kFALSE),
        fDecayer(0)
 {
-// Default constructor
+  // Default constructor
 }
 //____________________________________________________________
-AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library,  Int_t param, char* tname)
+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.),
@@ -83,9 +90,10 @@ AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library,  Int_t param, char* t
      fBias(0.),
      fTrials(0),
      fDeltaPt(0.01),
+     fSelectAll(kFALSE),
      fDecayer(0)
 {
-// 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";
     fAnalog = kAnalog;
@@ -97,8 +105,11 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char
     fPtParaFunc(0),
     fYParaFunc (0),
     fIpParaFunc(0),
+  fV2ParaFunc(0),
     fPtPara(0),
     fYPara(0),
+  fV2Para(0),
+  fdNdPhi(0),
     fParam(param),
     fdNdy0(0.),
     fYWgt(0.),
@@ -106,10 +117,11 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char
     fBias(0.),
     fTrials(0),
     fDeltaPt(0.01),
+    fSelectAll(kFALSE),
     fDecayer(0)
 {
-// Constructor using parameterisation id and number of particles
-//
+  // Constructor using parameterisation id and number of particles
+  //
     fName = name;
     fTitle= "Particle Generator using pT and y parameterisation";
       
@@ -117,6 +129,7 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char
     fPtParaFunc = pLibrary->GetPt(param, tname);
     fYParaFunc  = pLibrary->GetY (param, tname);
     fIpParaFunc = pLibrary->GetIp(param, tname);
+  fV2ParaFunc = pLibrary->GetV2(param, tname);
     
     fAnalog = kAnalog;
     fChildSelect.Set(5);
@@ -131,16 +144,20 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char
 //____________________________________________________________
 
 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),
      
      fPtParaFunc(PtPara),
      fYParaFunc(YPara),
      fIpParaFunc(IpPara),
+   fV2ParaFunc(V2Para),
      fPtPara(0),
      fYPara(0),
+   fV2Para(0),
+   fdNdPhi(0),
      fParam(param),
      fdNdy0(0.),
      fYWgt(0.),
@@ -148,10 +165,11 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param,
      fBias(0.),
      fTrials(0),
      fDeltaPt(0.01),
+     fSelectAll(kFALSE),
      fDecayer(0)
 {
-// Constructor
-// Gines Martinez 1/10/99 
+  // Constructor
+  // Gines Martinez 1/10/99 
     fName = "Param";
     fTitle= "Particle Generator using pT and y parameterisation";
 
@@ -169,15 +187,17 @@ AliGenParam::AliGenParam(Int_t npart, Int_t param,
 //____________________________________________________________
 AliGenParam::~AliGenParam()
 {
-// Destructor
+  // Destructor
     delete  fPtPara;
     delete  fYPara;
+  delete  fV2Para;
+  delete  fdNdPhi;
 }
 
 //____________________________________________________________
 void AliGenParam::Init()
 {
-// Initialisation
+  // Initialisation
 
     if (gMC) fDecayer = gMC->GetDecayer();
   //Begin_Html
@@ -186,39 +206,52 @@ void AliGenParam::Init()
   */
   //End_Html
     char name[256];
-    sprintf(name, "pt-parameterisation for %s", GetName());
+    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
+  //  Set representation precision to 10 MeV
     Int_t npx= Int_t((fPtMax - fPtMin) / fDeltaPt);
     
     fPtPara->SetNpx(npx);
 
-    sprintf(name, "y-parameterisation  for %s", GetName());
+    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?
     
-    sprintf(name, "pt-for-%s", GetName());
+  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?
+    
+    snprintf(name, 256, "pt-for-%s", GetName());
     TF1 ptPara(name ,fPtParaFunc, 0, 15, 0);
-    sprintf(name, "y-for-%s", GetName());
+    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
+  //
+  // Integral over generation region
     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);
-    Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
+  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;
@@ -228,36 +261,45 @@ 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
+  // 
+  // 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], 
@@ -274,36 +316,36 @@ 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
+  // Generating fNpart particles
   fNprimaries = 0;
   
-  while (ipa<fNpart) {
+  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;
@@ -320,15 +362,25 @@ 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;
@@ -339,25 +391,29 @@ 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);
 
              //  Selecting  GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
@@ -377,14 +433,14 @@ void AliGenParam::Generate()
              
              if (np >1) {
                  decayed = kTRUE;
-                 TParticle* iparticle =  (TParticle *) particles->At(0);
+                 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();
@@ -393,14 +449,14 @@ 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();       
@@ -410,10 +466,10 @@ 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();
@@ -438,18 +494,18 @@ void AliGenParam::Generate()
              Int_t iparent;
              if ((fCutOnChild && ncsel >0) || !fCutOnChild){
                  ipa++;
-//
-// Parent
+         //
+         // Parent
                  
                  
-                 PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp, ((decayed)? 11 : 1));
+                 PushTrack(0, -1, iPart, p, origin0, polar, time0, kPPrimary, nt, wgtp, ((decayed)? 11 : 1));
                  pParent[0] = nt;
                  KeepTrack(nt); 
                  fNprimaries++;
                  
-//
-// Decay Products
-//               
+         //
+         // Decay Products
+         //              
                  for (i = 1; i < np; i++) {
                      if (pSelected[i]) {
                          TParticle* iparticle = (TParticle *) particles->At(i);
@@ -457,9 +513,9 @@ void AliGenParam::Generate()
                          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();
@@ -472,7 +528,7 @@ void AliGenParam::Generate()
                         
                          PushTrack(fTrackIt * trackIt[i], iparent, kf,
                                           pc, och, polar,
-                                          0, kPDecay, nt, wgtch, ksc);
+                                          time0 + iparticle->T(), kPDecay, nt, wgtch, ksc);
                          pParent[i] = nt;
                          KeepTrack(nt); 
                          fNprimaries++;
@@ -488,7 +544,7 @@ void AliGenParam::Generate()
          else  // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
          {
            gAlice->GetMCApp()->
-               PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp, 1);
+               PushTrack(fTrackIt,-1,iPart,p,origin0,polar,time0,kPPrimary,nt,wgtp, 1);
             ipa++; 
            fNprimaries++;
          }
@@ -500,15 +556,16 @@ void AliGenParam::Generate()
 
   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
-//
+  //
+  // Normalisation for selected kinematic region
+  //
   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)   *