EVGEN/AliGenTunedOnPbPb.cxx

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  15
  16 /* $Id: AliGenTunedOnPbPb.cxx 51126 2013-08-19 13:37:49Z fnoferin $ */
  17
  18 // Parameterisation based on 5.5 ATeV PbPb data
  19 // pi,K, p , K0, lambda, phi, Xi, Omega spectra, v2, v3 (no jets!)
  20 // Author: fnoferin@cern.ch
  21
  22 #include <TArrayF.h>
  23 #include <TCanvas.h>
  24 #include <TClonesArray.h>
  25 #include <TDatabasePDG.h>
  26 #include <TF1.h>
  27 #include <TH1.h>
  28 #include <TPDGCode.h>
  29 #include <TParticle.h>
  30 #include <TROOT.h>
  31 #include <TVirtualMC.h>
  32 #include <TLorentzVector.h>
  33
  34 #include "AliConst.h"
  35 #include "AliDecayer.h"
  36 #include "AliGenEventHeaderTunedPbPb.h"
  37 #include "AliLog.h"
  38 #include "AliRun.h"
  39 #include "AliGenTunedOnPbPb.h"
  40
  41 ClassImp(AliGenTunedOnPbPb)
  42
  43 // set default parameters for 10-20% centrality
  44 Int_t AliGenTunedOnPbPb::fgPdgInput[fgNspecies] = {211,-211,111,321,-321,2212,-2212,310,3122,-3122,333,3312,-3312,3334,-3334};
  45 Float_t AliGenTunedOnPbPb::fgMult[fgNspecies] = {450,450,450,70,70,21,21,70,20,20,8,2.4,2.4,0.4,0.4};
  46
  47 Float_t AliGenTunedOnPbPb::fgV3Overv2 = 6.25000000000000000e-01;
  48 Float_t AliGenTunedOnPbPb::fgEventplane=0;
  49
  50 TF1 *AliGenTunedOnPbPb::fgV2 = NULL;
  51
  52 //_____________________________________________________________________________
  53 AliGenTunedOnPbPb::AliGenTunedOnPbPb()
  54   :AliGenerator(),
  55    fCmin(0.),
  56    fCmax(100.),
  57    fChangeWithCentrality(kFALSE),
  58    fYMaxValue(2.0),
  59    fYlimitForFlatness(2.0),
  60    fYdecreaseSp(0.2),
  61    fYdecreaseV2(0.2)
  62 {
  63     //
  64     // Default constructor
  65     //
  66     SetCutVertexZ();
  67     SetPtRange();
  68
  69     for(Int_t i=0;i < fgNspecies;i++){
  70       fgHSpectrum[i] = NULL;
  71       fgHv2[i] = NULL;
  72     }
  73 }
  74
  75 //_____________________________________________________________________________
  76 AliGenTunedOnPbPb::~AliGenTunedOnPbPb()
  77 {
  78   //
  79   // Standard destructor
  80   //
  81 }
  82
  83 //_____________________________________________________________________________
  84 void AliGenTunedOnPbPb::Init()
  85 {
  86   //
  87   // Initialise the generator
  88   //
  89
  90   // define histos
  91 }
  92
  93
  94 //_____________________________________________________________________________
  95 void AliGenTunedOnPbPb::Generate()
  96 {
  97   //
  98   // Generate one trigger
  99   //
 100
 101   Float_t avCentr = (fCmin+fCmax)*0.5;
 102
 103   Float_t centrality = avCentr;
 104
 105   if(fChangeWithCentrality) centrality = fCmin + gRandom->Rndm()*(fCmax-fCmin);
 106
 107   SetParameters(centrality);
 108
 109   if(!fChangeWithCentrality){
 110     Float_t in=0;
 111     for(Int_t i=0;i < fgNspecies;i++){
 112       in=0;
 113       if(fgHSpectrum[i]){
 114         for(Int_t j=1;j<=fgHSpectrum[i]->GetNbinsX();j++){
 115           in += fgHSpectrum[i]->GetBinContent(j)*fgHSpectrum[i]->GetBinWidth(j);
 116         }
 117       }
 118
 119       // replace n-particles with the one in input file if centralidy dependece was disable
 120       fgMult[i] = in;
 121     }
 122   }
 123
 124
 125   TMCProcess statusPdg[fgNspecies] = {kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary,kPPrimary};
 126
 127   Float_t parV2scaling[3] = {1,0.202538,-0.00214468};
 128
 129   Float_t scaleV2 = 1.0;
 130
 131   TDatabasePDG *pdgD = TDatabasePDG::Instance();
 132
 133   if(fChangeWithCentrality){
 134     parV2scaling[0] = 1. / (1 + parV2scaling[1]*avCentr + parV2scaling[2]*avCentr*avCentr); // normalize to average centrality
 135
 136     scaleV2 = parV2scaling[0]*(1 + parV2scaling[1]*centrality + parV2scaling[2]*centrality*centrality); // apply the trand of v2 w.r.t. centrality
 137   }
 138
 139   fgV2->SetParameter(2,fgV3Overv2);
 140
 141   Float_t psi = gRandom->Rndm()*TMath::Pi();
 142   fgEventplane = psi;
 143   Float_t psi3 = gRandom->Rndm()*TMath::Pi()*2/3;
 144   fgV2->SetParameter(1,psi);
 145   fgV2->SetParameter(3,psi3);
 146
 147   Int_t npart = 0;
 148
 149   Float_t origin0[3];
 150   for (Int_t j=0;j<3;j++) origin0[j]=fOrigin[j];
 151   Float_t time;
 152   time = fTimeOrigin;
 153   if(fVertexSmear == kPerEvent) {
 154     Vertex();
 155     for (Int_t j=0; j < 3; j++) origin0[j] = fVertex[j];
 156     time = fTime;
 157   } // if kPerEvent
 158
 159   printf("Generate event with centrality = %3.1f%c, |y|<%4.1f\n",centrality,'%',fYMaxValue);
 160
 161   for(Int_t isp=0;isp < fgNspecies;isp++){
 162     if(! fgHSpectrum[isp]) continue;
 163
 164     Int_t npartSp = Int_t(fgMult[isp]*2*fYMaxValue + gRandom->Rndm());
 165
 166     printf("Total number of %i = %i\n",fgPdgInput[isp],npartSp);
 167
 168     for(Int_t ipart =0; ipart < npartSp; ipart++){
 169       Int_t pdg = fgPdgInput[isp];
 170
 171       Double_t y = gRandom->Rndm()*2*fYMaxValue - fYMaxValue;
 172       Double_t ytanh = TMath::TanH(y);
 173       Double_t pt = fgHSpectrum[isp]->GetRandom();
 174       Double_t mass = pdgD->GetParticle(pdg)->Mass();
 175       Double_t mt2 = pt*pt + mass*mass;
 176       Double_t pz = ytanh*TMath::Sqrt(mt2)/TMath::Sqrt(1-ytanh*ytanh);
 177       Double_t etot = TMath::Sqrt(mt2 + pz*pz);
 178       TLorentzVector tempVect(pt,0,pz,etot);
 179       Double_t eta = tempVect.PseudoRapidity();
 180       Double_t scaleEtaV2 = 1; // set the eta dependence
 181       if(TMath::Abs(y)> fYlimitForFlatness) scaleEtaV2 = 1 - fYdecreaseV2*(TMath::Abs(y) - fYlimitForFlatness);
 182
 183       if(fgHv2[isp]) fgV2->SetParameter(0,fgHv2[isp]->Interpolate(pt) * scaleV2 * scaleEtaV2);
 184       else fgV2->SetParameter(0,0.);
 185       Double_t phi = fgV2->GetRandom(-TMath::Pi(),TMath::Pi());
 186       Double_t px = pt*TMath::Cos(phi);
 187       Double_t py = pt*TMath::Sin(phi);
 188       Float_t p[3] = {px,py,pz};
 189       Float_t polar[3] = {0.,0.,0.};
 190
 191       if(TMath::Abs(y)< fYlimitForFlatness || gRandom->Rndm() < 1 - fYdecreaseSp*(TMath::Abs(y) - fYlimitForFlatness)){// check on pseudorapidity distribution
 192         //      printf("%f %f\n",eta,phi - psi); // for debugging
 193         PushTrack(1, -1, pdg, p, origin0, polar, time, statusPdg[isp], npart, 1., 1);
 194         KeepTrack(npart);
 195         npart++;
 196       }
 197     }
 198   }
 199
 200   TArrayF eventVertex;
 201   eventVertex.Set(3);
 202   eventVertex[0] = origin0[0];
 203   eventVertex[1] = origin0[1];
 204   eventVertex[2] = origin0[2];
 205
 206 // Header
 207     AliGenEventHeaderTunedPbPb* header = new AliGenEventHeaderTunedPbPb("tunedOnPbPb");
 208 // Event Vertex
 209     header->SetPrimaryVertex(eventVertex);
 210     header->SetInteractionTime(time);
 211     header->SetNProduced(npart);
 212     header->SetCentrality(centrality);
 213     header->SetPsi2(psi);
 214     header->SetPsi3(psi3);
 215     gAlice->SetGenEventHeader(header);
 216 }
 217
 218 void AliGenTunedOnPbPb::SetPtRange(Float_t ptmin, Float_t ptmax) {
 219     AliGenerator::SetPtRange(ptmin, ptmax);
 220 }
 221 //_____________________________________________________________________________
 222 TH1F *AliGenTunedOnPbPb::GetMultVsCentrality(Int_t species){
 223   char title[100];
 224   snprintf(title,100,"pdg = %i;centrality;dN/dy",fgPdgInput[species]);
 225   TH1F *h = new TH1F("multVsCentr",title,100,0,100);
 226
 227   for(Int_t i=1;i<=100;i++){
 228     Float_t x = i+0.5;
 229     SetParameters(x);
 230     h->SetBinContent(i,fgMult[species]);
 231   }
 232
 233   return h;
 234 }
 235 //_____________________________________________________________________________
 236 void AliGenTunedOnPbPb::SetParameters(Float_t centrality){
 237
 238   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());
 239
 240   Float_t fr[9] = {0.,0.,0.,0.,0.,0.,0.,0.,0.};
 241
 242   if(centrality < 7.5){
 243     fr[0] = (7.5 - centrality)/5.;
 244     fr[1] = (centrality-2.5)/5.;
 245   }
 246   else if(centrality < 15){
 247     fr[1] = (15-centrality)/7.5;
 248     fr[2] = (centrality-7.5)/7.5;
 249   }
 250   else if(centrality < 25){
 251     fr[2] = (25-centrality)/10.;
 252     fr[3] = (centrality-15)/10.;
 253   }
 254   else if(centrality < 35){
 255     fr[3] = (35-centrality)/10.;
 256     fr[4] = (centrality-25)/10.;
 257   }
 258   else if(centrality < 45){
 259     fr[4] = (45-centrality)/10.;
 260     fr[5] = (centrality-35)/10.;
 261   }
 262   else if(centrality < 55){
 263     fr[5] = (55-centrality)/10.;
 264     fr[6] = (centrality-45)/10.;
 265   }
 266   else if(centrality < 65){
 267     fr[6] = (65-centrality)/10.;
 268     fr[7] = (centrality-55)/10.;
 269   }
 270   else if(centrality < 75){
 271     fr[7] = (75-centrality)/10.;
 272     fr[8] = (centrality-65)/10.;
 273   }
 274   else{
 275     fr[8] = 1.0;
 276   }
 277
 278   // parameters as a function of centrality
 279   Float_t multCent[9*fgNspecies] = {733.,733.,733.,109.,109.,34.,34.,109.,28.,28.,11.5,3.1,3.1,0.5,0.5,
 280                                     606.,606.,606.,91.,91.,28.,28.,91.,24.,24.,9.,2.7,2.7,0.45,0.45,
 281                                     455.,455.,455.,68.,68.,21.,21.,68.,20.,20.,8.,2.4,2.4,0.4,0.4,
 282                                     307.,307.,307.,46.,46.,14.5,14.5,46.,14.,14.,5.5,1.5,1.5,0.2,0.2,
 283                                     201.,201.,201.,30.,30.,9.6,9.6,30.,9.,9.,3.5,0.9,0.9,0.08,0.08,
 284                                     124.,124.,124.,18.3,18.3,6.1,6.1,18.3,5.1,5.1,2.2,0.6,0.6,0.055,0.055,
 285                                     71.,71.,71.,10.2,10.2,3.6,3.6,10.2,2.6,2.6,1.4,0.36,0.36,0.035,0.035,
 286                                     37.,37.,37.,5.1,5.1,2.,2.,5.1,1.5,1.5,0.5,0.02,0.02,0.015,0.015,
 287                                     17.,17.,17.,2.3,2.3,0.9,0.9,2.3,0.6,0.6,0.16,0.006,0.006,0.005,0.005};
 288
 289   Float_t v3Overv2Cent[9] = {1.2,0.82,0.625,0.5,0.45,0.4,0.37,0.3,0.3};
 290
 291   fgV3Overv2 = 0;
 292   for(Int_t j=0;j < 9;j++)
 293       fgV3Overv2 += fr[j]*v3Overv2Cent[j];
 294
 295   // set parameters for current centrality
 296   for(Int_t i=0;i < fgNspecies;i++){
 297     fgMult[i] = 0;
 298
 299     for(Int_t j=0;j < 9;j++){
 300       fgMult[i] += fr[j]*multCent[i+j*fgNspecies];
 301     }
 302   }
 303
 304   if(centrality > 80){
 305     for(Int_t i=0;i < fgNspecies;i++)
 306       fgMult[i] /= TMath::Log(centrality-77.);
 307   }
 308 }