Introducing the interaction time into the aliroot generators. In case of gaussian...
[u/mrichter/AliRoot.git] / EVGEN / AliGenHIJINGpara.cxx
index dc4b01a..737b0cd 100644 (file)
 ///////////////////////////////////////////////////////////////////
 
 #include <TArrayF.h>
+#include <TCanvas.h>
 #include <TClonesArray.h>
 #include <TDatabasePDG.h>
 #include <TF1.h>
-#include <TParticle.h>
+#include <TH1.h>
 #include <TPDGCode.h>
+#include <TParticle.h>
+#include <TROOT.h>
 #include <TVirtualMC.h>
 
 #include "AliConst.h"
 #include "AliDecayer.h"
 #include "AliGenEventHeader.h"
 #include "AliGenHIJINGpara.h"
+#include "AliLog.h"
 #include "AliRun.h"
 
 ClassImp(AliGenHIJINGpara)
 
 
-AliGenHIJINGpara::AliGenHIJINGpara(const AliGenHIJINGpara & para):
-    AliGenerator(para)
-{
-// Copy constructor
-    para.Copy(*this);
-}
 
 //_____________________________________________________________________________
-static Double_t ptpi(Double_t *px, Double_t *)
+static Double_t ptpi(const Double_t *px, const Double_t *)
 {
   //
   //     PT-PARAMETERIZATION CDF, PRL 61(88) 1819
   //     POWER LAW FOR PT > 500 MEV
   //     MT SCALING BELOW (T=160 MEV)
   //
-  const Double_t kp0 = 1.3;
-  const Double_t kxn = 8.28;
-  const Double_t kxlim=0.5;
-  const Double_t kt=0.160;
-  const Double_t kxmpi=0.139;
-  const Double_t kb=1.;
+  const Double_t kp0    = 1.3;
+  const Double_t kxn    = 8.28;
+  const Double_t kxlim  = 0.5;
+  const Double_t kt     = 0.160;
+  const Double_t kxmpi  = 0.139;
+  const Double_t kb     = 1.;
   Double_t y, y1, xmpi2, ynorm, a;
-  Double_t x=*px;
+  Double_t x = *px;
   //
-  y1=TMath::Power(kp0/(kp0+kxlim),kxn);
-  xmpi2=kxmpi*kxmpi;
-  ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+xmpi2)/kt));
-  a=ynorm/y1;
+  y1 = TMath::Power(kp0 / (kp0 + kxlim), kxn);
+  xmpi2 = kxmpi * kxmpi;
+  ynorm = kb * (TMath::Exp(-sqrt(kxlim * kxlim + xmpi2) / kt ));
+  a = ynorm / y1;
   if (x > kxlim)
-    y=a*TMath::Power(kp0/(kp0+x),kxn);
+    y = a * TMath::Power(kp0 / (kp0 + x), kxn);
   else
-    y=kb*TMath::Exp(-sqrt(x*x+xmpi2)/kt);
+    y = kb* TMath::Exp(-sqrt(x * x + xmpi2) / kt);
+  
   return y*x;
 }
 
@@ -159,40 +158,46 @@ static Double_t etakac( Double_t *py, Double_t *)
 
 //_____________________________________________________________________________
 AliGenHIJINGpara::AliGenHIJINGpara()
-  :AliGenerator()
+    :AliGenerator(),
+       fNt(-1),
+       fNpartProd(0),
+       fPi0Decays(kFALSE),
+       fPtWgtPi(0.),
+       fPtWgtKa(0.),
+       fPtpi(0),
+       fPtka(0),
+       fETApic(0),
+       fETAkac(0),
+       fDecayer(0)
 {
     //
     // Default constructor
     //
-    fPtpi    =  0;
-    fPtka    =  0;
-    fETApic  =  0;
-    fETAkac  =  0;
-    fDecayer =  0;
-    fNt      = -1;
     SetCutVertexZ();
     SetPtRange();
-    SetPi0Decays();
 }
 
 //_____________________________________________________________________________
 AliGenHIJINGpara::AliGenHIJINGpara(Int_t npart)
-  :AliGenerator(npart)
+    :AliGenerator(npart),
+       fNt(-1),
+       fNpartProd(npart),
+       fPi0Decays(kFALSE),
+       fPtWgtPi(0.),
+       fPtWgtKa(0.),
+       fPtpi(0),
+       fPtka(0),
+       fETApic(0),
+       fETAkac(0),
+       fDecayer(0)
 {
   // 
   // Standard constructor
   //
     fName="HIJINGpara";
     fTitle="HIJING Parametrisation Particle Generator";
-    fPtpi    =  0;
-    fPtka    =  0;
-    fETApic  =  0;
-    fETAkac  =  0;
-    fDecayer =  0;
-    fNt      = -1;
     SetCutVertexZ();
     SetPtRange();
-    SetPi0Decays();
 }
 
 //_____________________________________________________________________________
@@ -218,15 +223,21 @@ void AliGenHIJINGpara::Init()
     Float_t etaMax = -TMath::Log(TMath::Tan(
        TMath::Max((Double_t)fThetaMin/2,1.e-10)));
     fPtpi   = new TF1("ptpi",&ptpi,0,20,0);
+    gROOT->GetListOfFunctions()->Remove(fPtpi);
     fPtka   = new TF1("ptka",&ptka,0,20,0);
+    gROOT->GetListOfFunctions()->Remove(fPtka);
+    fPtpi->SetNpx(1000);
+    fPtka->SetNpx(1000);
     fETApic = new TF1("etapic",&etapic,etaMin,etaMax,0);
+    gROOT->GetListOfFunctions()->Remove(fETApic);
     fETAkac = new TF1("etakac",&etakac,etaMin,etaMax,0);
+    gROOT->GetListOfFunctions()->Remove(fETAkac);
 
-    TF1 etaPic0("etapic",&etapic,-7,7,0);
-    TF1 etaKac0("etakac",&etakac,-7,7,0);
+    TF1 etaPic0("etaPic0",&etapic,-7,7,0);
+    TF1 etaKac0("etaKac0",&etakac,-7,7,0);
 
-    TF1 ptPic0("ptpi",&ptpi,0.,15.,0);
-    TF1 ptKac0("ptka",&ptka,0.,15.,0);
+    TF1 ptPic0("ptPic0",&ptpi,0.,15.,0);
+    TF1 ptKac0("ptKac0",&ptka,0.,15.,0);
 
     Float_t intETApi  = etaPic0.Integral(-0.5, 0.5);
     Float_t intETAka  = etaKac0.Integral(-0.5, 0.5);
@@ -247,30 +258,36 @@ void AliGenHIJINGpara::Init()
     Float_t phiFrac    = (fPhiMax-fPhiMin)/2/TMath::Pi();
 
     
-    fParentWeight = Float_t(fNpart)/(intETASel*ptFrac*phiFrac);
+    fParentWeight = (intETASel*ptFrac*phiFrac) / Float_t(fNpart);
     
     if (fAnalog != 0) {
        fPtWgtPi = (fPtMax - fPtMin) / fPtpi->Integral(0., 20.);
        fPtWgtKa = (fPtMax - fPtMin) / fPtka->Integral(0., 20.);
-       fParentWeight = Float_t(fNpart)/(intETASel*phiFrac);
+       fParentWeight = (intETASel*phiFrac) / Float_t(fNpart);
     }
     
     
-    printf("%s: The number of particles in the selected kinematic region corresponds to %f percent of a full event\n ", 
-          ClassName(),100.*fParentWeight);
+    AliInfo(Form("The number of particles in the selected kinematic region corresponds to %f percent of a full event", 
+                100./ fParentWeight));
 
 // Issue warning message if etaMin or etaMax are outside the alowed range 
 // of the parametrization
     if (etaMin < -8.001 || etaMax > 8.001) {
-       printf("\n \n WARNING FROM AliGenHIJINGPara !");
-       printf("\n YOU ARE USING THE PARAMETERISATION OUTSIDE ");       
-       printf("\n THE ALLOWED PSEUDORAPIDITY RANGE (-8. - 8.)");           
-       printf("\n YOUR LIMITS: %f %f \n \n ", etaMin, etaMax);
+       AliWarning("\nYOU ARE USING THE PARAMETERISATION OUTSIDE ");    
+       AliWarning("THE ALLOWED PSEUDORAPIDITY RANGE (-8. - 8.)");          
+       AliWarning(Form("YOUR LIMITS: %f %f \n ", etaMin, etaMax));
     }
 //
 //
     if (fPi0Decays && gMC)
        fDecayer = gMC->GetDecayer();
+
+    if (fPi0Decays)
+    {
+       fDecayer->SetForceDecay(kNeutralPion);
+       fDecayer->Init();
+    }
+    
 }
 
 
@@ -290,6 +307,7 @@ void AliGenHIJINGpara::Generate()
     const Int_t kKaons[4] = {kK0Long, kK0Short, kKPlus, kKMinus};
     //
     Float_t origin[3];
+    Float_t time;
     Float_t pt, pl, ptot, wgt;
     Float_t phi, theta;
     Float_t p[3];
@@ -301,16 +319,19 @@ void AliGenHIJINGpara::Generate()
     Float_t random[6];
     //
     for (j=0;j<3;j++) origin[j]=fOrigin[j];
+    time = fTimeOrigin;
 
     if(fVertexSmear == kPerEvent) {
        Vertex();
        for (j=0; j < 3; j++) origin[j] = fVertex[j];
+       time = fTime;
     } // if kPerEvent
     TArrayF eventVertex;
     eventVertex.Set(3);
     eventVertex[0] = origin[0];
     eventVertex[1] = origin[1];
     eventVertex[2] = origin[2];
+    Float_t eventTime = time;
      
     for(i=0;i<fNpart;i++) {
        while(1) {
@@ -349,8 +370,12 @@ void AliGenHIJINGpara::Generate()
                    origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
                        TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
                }
+               Rndm(random,2);
+               time = fTimeOrigin + fOsigma[2]/TMath::Ccgs()*
+                 TMath::Cos(2*random[0]*TMath::Pi())*
+                 TMath::Sqrt(-2*TMath::Log(random[1]));
            }
-           
+
            if (fAnalog == 0) { 
                wgt = fParentWeight;
            } else {
@@ -361,11 +386,13 @@ void AliGenHIJINGpara::Generate()
            if (part == kPi0 && fPi0Decays){
 //
 //          Decay pi0 if requested
-               PushTrack(0,-1,part,p,origin,polar,0,kPPrimary,fNt,fParentWeight);
+               PushTrack(0,-1,part,p,origin,polar,time,kPPrimary,fNt,wgt);
                KeepTrack(fNt);
-               DecayPi0(origin, p);
+               DecayPi0(origin, p, time);
            } else {
-               PushTrack(fTrackIt,-1,part,p,origin,polar,0,kPPrimary,fNt,fParentWeight);
+      // printf("fNt %d", fNt);
+               PushTrack(fTrackIt,-1,part,p,origin,polar,time,kPPrimary,fNt,wgt);
+
                KeepTrack(fNt);
            }
 
@@ -379,6 +406,8 @@ void AliGenHIJINGpara::Generate()
     AliGenEventHeader* header = new AliGenEventHeader("HIJINGparam");
 // Event Vertex
     header->SetPrimaryVertex(eventVertex);
+    header->SetInteractionTime(eventTime);
+    header->SetNProduced(fNpartProd);
     gAlice->SetGenEventHeader(header); 
 }
 
@@ -386,7 +415,7 @@ void AliGenHIJINGpara::SetPtRange(Float_t ptmin, Float_t ptmax) {
     AliGenerator::SetPtRange(ptmin, ptmax);
 }
 
-void AliGenHIJINGpara::DecayPi0(Float_t* orig, Float_t * p) 
+void AliGenHIJINGpara::DecayPi0(Float_t* orig, Float_t * p, Float_t time) 
 {
 //
 //    Decay the pi0
@@ -407,7 +436,8 @@ void AliGenHIJINGpara::DecayPi0(Float_t* orig, Float_t * p)
 //
     Float_t polar[3] = {0., 0., 0.};
     Int_t np = fDecayer->ImportParticles(particles);
-    Int_t nt;    
+    fNpartProd += (np-1);
+    Int_t nt = 0;    
     for (Int_t i = 1; i < np; i++)
     {
        TParticle* iParticle =  (TParticle *) particles->At(i);
@@ -416,13 +446,24 @@ void AliGenHIJINGpara::DecayPi0(Float_t* orig, Float_t * p)
        p[2] = iParticle->Pz();
        Int_t part = iParticle->GetPdgCode();
 
-       PushTrack(fTrackIt, fNt, part, p, orig, polar, 0, kPDecay, nt, fParentWeight);
+       PushTrack(fTrackIt, fNt, part, p, orig, polar, time, kPDecay, nt, fParentWeight);
        KeepTrack(nt);
     }
     fNt = nt;
 }
 
-void AliGenHIJINGpara::Copy(AliGenHIJINGpara &) const
+void AliGenHIJINGpara::Draw( const char * /*opt*/)
 {
-  Fatal("Copy","Not implemented!\n");
+    //
+    // Draw the pT and y Distributions
+    //
+     TCanvas *c0 = new TCanvas("c0","Canvas 0",400,10,600,700);
+     c0->Divide(2,1);
+     c0->cd(1);
+     fPtpi->Draw();
+     fPtpi->GetHistogram()->SetXTitle("p_{T} (GeV)");     
+     c0->cd(2);
+     fPtka->Draw();
+     fPtka->GetHistogram()->SetXTitle("p_{T} (GeV)");     
+
 }