PWGCF/EBYE/BalanceFunctions/AliBalancePsi.cxx

   1 /**************************************************************************
   2  * Author: Panos Christakoglou.                                           *
   3  * Contributors are mentioned in the code where appropriate.              *
   4  *                                                                        *
   5  * Permission to use, copy, modify and distribute this software and its   *
   6  * documentation strictly for non-commercial purposes is hereby granted   *
   7  * without fee, provided that the above copyright notice appears in all   *
   8  * copies and that both the copyright notice and this permission notice   *
   9  * appear in the supporting documentation. The authors make no claims     *
  10  * about the suitability of this software for any purpose. It is          *
  11  * provided "as is" without express or implied warranty.                  *
  12  **************************************************************************/
  13
  14 /* $Id: AliBalancePsi.cxx 54125 2012-01-24 21:07:41Z miweber $ */
  15
  16 //-----------------------------------------------------------------
  17 //           Balance Function class
  18 //   This is the class to deal with the Balance Function wrt Psi analysis
  19 //   Origin: Panos Christakoglou, Nikhef, Panos.Christakoglou@cern.ch
  20 //-----------------------------------------------------------------
  21
  22
  23 //ROOT
  24 #include <Riostream.h>
  25 #include <TCanvas.h>
  26 #include <TMath.h>
  27 #include <TAxis.h>
  28 #include <TH2D.h>
  29 #include <TH3D.h>
  30 #include <TLorentzVector.h>
  31 #include <TObjArray.h>
  32 #include <TGraphErrors.h>
  33 #include <TString.h>
  34
  35 #include "AliVParticle.h"
  36 #include "AliMCParticle.h"
  37 #include "AliESDtrack.h"
  38 #include "AliAODTrack.h"
  39 #include "AliTHn.h"
  40 #include "AliAnalysisTaskTriggeredBF.h"
  41
  42 #include "AliBalancePsi.h"
  43
  44 ClassImp(AliBalancePsi)
  45
  46 //____________________________________________________________________//
  47 AliBalancePsi::AliBalancePsi() :
  48   TObject(),
  49   fShuffle(kFALSE),
  50   fAnalysisLevel("ESD"),
  51   fAnalyzedEvents(0) ,
  52   fCentralityId(0) ,
  53   fCentStart(0.),
  54   fCentStop(0.),
  55   fHistP(0),
  56   fHistN(0),
  57   fHistPN(0),
  58   fHistNP(0),
  59   fHistPP(0),
  60   fHistNN(0),
  61   fHistHBTbefore(0),
  62   fHistHBTafter(0),
  63   fHistConversionbefore(0),
  64   fHistConversionafter(0),
  65   fHistPsiMinusPhi(0),
  66   fPsiInterval(15.),
  67   fDeltaEtaMax(2.0),
  68   fHBTCut(kFALSE),
  69   fConversionCut(kFALSE),
  70   fEventClass("EventPlane"){
  71   // Default constructor
  72 }
  73
  74 //____________________________________________________________________//
  75 AliBalancePsi::AliBalancePsi(const AliBalancePsi& balance):
  76   TObject(balance), fShuffle(balance.fShuffle),
  77   fAnalysisLevel(balance.fAnalysisLevel),
  78   fAnalyzedEvents(balance.fAnalyzedEvents),
  79   fCentralityId(balance.fCentralityId),
  80   fCentStart(balance.fCentStart),
  81   fCentStop(balance.fCentStop),
  82   fHistP(balance.fHistP),
  83   fHistN(balance.fHistN),
  84   fHistPN(balance.fHistPN),
  85   fHistNP(balance.fHistNP),
  86   fHistPP(balance.fHistPP),
  87   fHistNN(balance.fHistNN),
  88   fHistHBTbefore(balance.fHistHBTbefore),
  89   fHistHBTafter(balance.fHistHBTafter),
  90   fHistConversionbefore(balance.fHistConversionbefore),
  91   fHistConversionafter(balance.fHistConversionafter),
  92   fHistPsiMinusPhi(balance.fHistPsiMinusPhi),
  93   fPsiInterval(balance.fPsiInterval),
  94   fDeltaEtaMax(balance.fDeltaEtaMax),
  95   fHBTCut(balance.fHBTCut),
  96   fConversionCut(balance.fConversionCut),
  97   fEventClass("EventPlane"){
  98   //copy constructor
  99 }
 100
 101 //____________________________________________________________________//
 102 AliBalancePsi::~AliBalancePsi() {
 103   // Destructor
 104   delete fHistP;
 105   delete fHistN;
 106   delete fHistPN;
 107   delete fHistNP;
 108   delete fHistPP;
 109   delete fHistNN;
 110
 111   delete fHistHBTbefore;
 112   delete fHistHBTafter;
 113   delete fHistConversionbefore;
 114   delete fHistConversionafter;
 115   delete fHistPsiMinusPhi;
 116
 117 }
 118
 119 //____________________________________________________________________//
 120 void AliBalancePsi::InitHistograms() {
 121   // single particle histograms
 122
 123   // global switch disabling the reference
 124   // (to avoid "Replacing existing TH1" if several wagons are created in train)
 125   Bool_t oldStatus = TH1::AddDirectoryStatus();
 126   TH1::AddDirectory(kFALSE);
 127
 128   Int_t anaSteps   = 1;       // analysis steps
 129   Int_t iBinSingle[kTrackVariablesSingle];        // binning for track variables
 130   Double_t* dBinsSingle[kTrackVariablesSingle];   // bins for track variables
 131   TString axisTitleSingle[kTrackVariablesSingle]; // axis titles for track variables
 132
 133   // two particle histograms
 134   Int_t iBinPair[kTrackVariablesPair];         // binning for track variables
 135   Double_t* dBinsPair[kTrackVariablesPair];    // bins for track variables
 136   TString axisTitlePair[kTrackVariablesPair];  // axis titles for track variables
 137   /**********************************************************
 138
 139   ======> Modification: Change Event Classification Scheme
 140
 141   ---> fEventClass == "EventPlane"
 142
 143    Default operation with Event Plane
 144
 145   ---> fEventClass == "Multiplicity"
 146
 147    Work with kTPCITStracklet multiplicity (from GetReferenceMultiplicity)
 148
 149   ---> fEventClass == "Centrality"
 150
 151    Work with Centrality Bins
 152
 153   ***********************************************************/
 154
 155   //--- Multiplicity Bins ------------------------------------
 156     const Int_t kMultBins = 8;
 157     //A first rough attempt at four bins
 158     Double_t kMultBinLimits[kMultBins+1]={0,10,20,30,40,50,60,70,80};
 159   //----------------------------------------------------------
 160
 161   //--- Centrality Bins --------------------------------------
 162     const Int_t kNCentralityBins = 9;
 163     Double_t centralityBins[kNCentralityBins+1] = {0.,5.,10.,20.,30.,40.,50.,60.,70.,80.};
 164   //----------------------------------------------------------
 165
 166   //--- Event Plane Bins -------------------------------------
 167     //Psi_2: -0.5->0.5 (in plane), 0.5->1.5 (intermediate), 1.5->2.5 (out of plane), 2.5->3.5 (rest)
 168     const Int_t kNPsi2Bins = 4;
 169     Double_t psi2Bins[kNPsi2Bins+1] = {-0.5,0.5,1.5,2.5,3.5};
 170   //----------------------------------------------------------
 171
 172   //Depending on fEventClass Variable, do one thing or the other...
 173     if(fEventClass == "Multiplicity"){
 174         iBinSingle[0]       = kMultBins;
 175         dBinsSingle[0]      = kMultBinLimits;
 176         axisTitleSingle[0]  = "kTPCITStracklet multiplicity";
 177         iBinPair[0]       = kMultBins;
 178         dBinsPair[0]      = kMultBinLimits;
 179         axisTitlePair[0]  = "kTPCITStracklet multiplicity";
 180     }
 181     if(fEventClass == "Centrality"){
 182         iBinSingle[0]       = kNCentralityBins;
 183         dBinsSingle[0]      = centralityBins;
 184         axisTitleSingle[0]  = "Centrality percentile [%]";
 185         iBinPair[0]       = kNCentralityBins;
 186         dBinsPair[0]      = centralityBins;
 187         axisTitlePair[0]  = "Centrality percentile [%]";
 188     }
 189     if(fEventClass == "EventPlane"){
 190         iBinSingle[0]       = kNPsi2Bins;
 191         dBinsSingle[0]      = psi2Bins;
 192         axisTitleSingle[0]  = "#varphi - #Psi_{2} (a.u.)";
 193         iBinPair[0]       = kNPsi2Bins;
 194         dBinsPair[0]      = psi2Bins;
 195         axisTitlePair[0]  = "#varphi - #Psi_{2} (a.u.)";
 196     }
 197
 198    // delta eta
 199   const Int_t kNDeltaEtaBins = 80;
 200   Double_t deltaEtaBins[kNDeltaEtaBins+1];
 201   for(Int_t i = 0; i < kNDeltaEtaBins+1; i++)
 202     deltaEtaBins[i] = - fDeltaEtaMax + i * 2 * fDeltaEtaMax / (Double_t)kNDeltaEtaBins;
 203   iBinPair[1]       = kNDeltaEtaBins;
 204   dBinsPair[1]      = deltaEtaBins;
 205   axisTitlePair[1]  = "#Delta#eta";
 206
 207    // delta phi
 208   const Int_t kNDeltaPhiBins = 72;
 209   Double_t deltaPhiBins[kNDeltaPhiBins+1];
 210   for(Int_t i = 0; i < kNDeltaPhiBins+1; i++){
 211     //deltaPhiBins[i] = -180.0 + i * 5.;
 212     deltaPhiBins[i] = -TMath::Pi()/2. + i * 5.*TMath::Pi()/180.;
 213   }
 214   iBinPair[2]       = kNDeltaPhiBins;
 215   dBinsPair[2]      = deltaPhiBins;
 216   axisTitlePair[2]  = "#Delta#varphi (rad)";
 217
 218   // pt(trigger-associated)
 219   const Int_t kNPtBins = 16;
 220   Double_t ptBins[kNPtBins+1] = {0.2,0.6,1.0,1.5,2.0,2.5,3.0,3.5,4.0,5.0,6.0,7.0,8.0,10.,12.,15.,20.};
 221   //for(Int_t i = 0; i < kNPtBins+1; i++){
 222   //ptBins[i] = 0.2 + i * 0.5;
 223   //}
 224   iBinSingle[1]       = kNPtBins;
 225   dBinsSingle[1]      = ptBins;
 226   axisTitleSingle[1]  = "p_{T,trig.} (GeV/c)";
 227
 228   iBinPair[3]       = kNPtBins;
 229   dBinsPair[3]      = ptBins;
 230   axisTitlePair[3]  = "p_{T,trig.} (GeV/c)";
 231
 232   iBinPair[4]       = kNPtBins;
 233   dBinsPair[4]      = ptBins;
 234   axisTitlePair[4]  = "p_{T,assoc.} (GeV/c)";
 235
 236   TString histName;
 237   //+ triggered particles
 238   histName = "fHistP";
 239   if(fShuffle) histName.Append("_shuffle");
 240   if(fCentralityId) histName += fCentralityId.Data();
 241   fHistP = new AliTHn(histName.Data(),histName.Data(),anaSteps,kTrackVariablesSingle,iBinSingle);
 242   for (Int_t j=0; j<kTrackVariablesSingle; j++) {
 243     fHistP->SetBinLimits(j, dBinsSingle[j]);
 244     fHistP->SetVarTitle(j, axisTitleSingle[j]);
 245   }
 246
 247   //- triggered particles
 248   histName = "fHistN";
 249   if(fShuffle) histName.Append("_shuffle");
 250   if(fCentralityId) histName += fCentralityId.Data();
 251   fHistN = new AliTHn(histName.Data(),histName.Data(),anaSteps,kTrackVariablesSingle,iBinSingle);
 252   for (Int_t j=0; j<kTrackVariablesSingle; j++) {
 253     fHistN->SetBinLimits(j, dBinsSingle[j]);
 254     fHistN->SetVarTitle(j, axisTitleSingle[j]);
 255   }
 256
 257   //+- pairs
 258   histName = "fHistPN";
 259   if(fShuffle) histName.Append("_shuffle");
 260   if(fCentralityId) histName += fCentralityId.Data();
 261   fHistPN = new AliTHn(histName.Data(),histName.Data(),anaSteps, kTrackVariablesPair, iBinPair);
 262   for (Int_t j=0; j<kTrackVariablesPair; j++) {
 263     fHistPN->SetBinLimits(j, dBinsPair[j]);
 264     fHistPN->SetVarTitle(j, axisTitlePair[j]);
 265   }
 266
 267   //-+ pairs
 268   histName = "fHistNP";
 269   if(fShuffle) histName.Append("_shuffle");
 270   if(fCentralityId) histName += fCentralityId.Data();
 271   fHistNP = new AliTHn(histName.Data(),histName.Data(),anaSteps, kTrackVariablesPair, iBinPair);
 272   for (Int_t j=0; j<kTrackVariablesPair; j++) {
 273     fHistNP->SetBinLimits(j, dBinsPair[j]);
 274     fHistNP->SetVarTitle(j, axisTitlePair[j]);
 275   }
 276
 277   //++ pairs
 278   histName = "fHistPP";
 279   if(fShuffle) histName.Append("_shuffle");
 280   if(fCentralityId) histName += fCentralityId.Data();
 281   fHistPP = new AliTHn(histName.Data(),histName.Data(),anaSteps, kTrackVariablesPair, iBinPair);
 282   for (Int_t j=0; j<kTrackVariablesPair; j++) {
 283     fHistPP->SetBinLimits(j, dBinsPair[j]);
 284     fHistPP->SetVarTitle(j, axisTitlePair[j]);
 285   }
 286
 287   //-- pairs
 288   histName = "fHistNN";
 289   if(fShuffle) histName.Append("_shuffle");
 290   if(fCentralityId) histName += fCentralityId.Data();
 291   fHistNN = new AliTHn(histName.Data(),histName.Data(),anaSteps, kTrackVariablesPair, iBinPair);
 292   for (Int_t j=0; j<kTrackVariablesPair; j++) {
 293     fHistNN->SetBinLimits(j, dBinsPair[j]);
 294     fHistNN->SetVarTitle(j, axisTitlePair[j]);
 295   }
 296   AliInfo("Finished setting up the AliTHn");
 297
 298   // QA histograms
 299   fHistHBTbefore        = new TH2D("fHistHBTbefore","before HBT cut",200,0,2,200,0,2.*TMath::Pi());
 300   fHistHBTafter         = new TH2D("fHistHBTafter","after HBT cut",200,0,2,200,0,2.*TMath::Pi());
 301   fHistConversionbefore = new TH2D("fHistConversionbefore","before Conversion cut",200,0,2,200,0,2.*TMath::Pi());
 302   fHistConversionafter  = new TH2D("fHistConversionafter","after Conversion cut",200,0,2,200,0,2.*TMath::Pi());
 303   fHistPsiMinusPhi     = new TH2D("fHistPsiMinusPhi","",4,-0.5,3.5,100,0,2.*TMath::Pi());
 304
 305   TH1::AddDirectory(oldStatus);
 306
 307 }
 308
 309 //____________________________________________________________________//
 310 void AliBalancePsi::CalculateBalance(Double_t gReactionPlane,
 311                                      TObjArray *particles,
 312                                      TObjArray *particlesMixed,
 313                      Float_t bSign,
 314                      Double_t kMultorCent) {
 315   // Calculates the balance function
 316   fAnalyzedEvents++;
 317
 318   // Initialize histograms if not done yet
 319   if(!fHistPN){
 320     AliWarning("Histograms not yet initialized! --> Will be done now");
 321     AliWarning("This works only in local mode --> Add 'gBalance->InitHistograms()' in your configBalanceFunction");
 322     InitHistograms();
 323   }
 324
 325   Double_t trackVariablesSingle[kTrackVariablesSingle];
 326   Double_t trackVariablesPair[kTrackVariablesPair];
 327
 328   if (!particles){
 329     AliWarning("particles TObjArray is NULL pointer --> return");
 330     return;
 331   }
 332
 333   // define end of particle loops
 334   Int_t iMax = particles->GetEntriesFast();
 335   Int_t jMax = iMax;
 336   if (particlesMixed)
 337     jMax = particlesMixed->GetEntriesFast();
 338
 339   // Eta() is extremely time consuming, therefore cache it for the inner loop here:
 340   TObjArray* particlesSecond = (particlesMixed) ? particlesMixed : particles;
 341
 342   TArrayF secondEta(jMax);
 343   TArrayF secondPhi(jMax);
 344   TArrayF secondPt(jMax);
 345   TArrayS secondCharge(jMax);
 346   TArrayD secondCorrection(jMax);
 347
 348   for (Int_t i=0; i<jMax; i++){
 349     secondEta[i] = ((AliVParticle*) particlesSecond->At(i))->Eta();
 350     secondPhi[i] = ((AliVParticle*) particlesSecond->At(i))->Phi();
 351     secondPt[i]  = ((AliVParticle*) particlesSecond->At(i))->Pt();
 352     secondCharge[i]  = (Short_t)((AliVParticle*) particlesSecond->At(i))->Charge();
 353     secondCorrection[i]  = (Double_t)((AliBFBasicParticle*) particlesSecond->At(i))->Correction();   //==========================correction
 354   }
 355
 356   // 1st particle loop
 357   for (Int_t i = 0; i < iMax; i++) {
 358     //AliVParticle* firstParticle = (AliVParticle*) particles->At(i);
 359     AliBFBasicParticle* firstParticle = (AliBFBasicParticle*) particles->At(i); //==========================correction
 360
 361     // some optimization
 362     Float_t firstEta = firstParticle->Eta();
 363     Float_t firstPhi = firstParticle->Phi();
 364     Float_t firstPt  = firstParticle->Pt();
 365     Float_t firstCorrection  = firstParticle->Correction();//==========================correction
 366
 367     // Event plane (determine psi bin)
 368     Double_t gPsiMinusPhi    =   0.;
 369     Double_t gPsiMinusPhiBin = -10.;
 370     gPsiMinusPhi   = TMath::Abs(firstPhi - gReactionPlane);
 371     //in-plane
 372     if((gPsiMinusPhi <= 7.5*TMath::DegToRad())||
 373        ((172.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 187.5*TMath::DegToRad())))
 374       gPsiMinusPhiBin = 0.0;
 375     //intermediate
 376     else if(((37.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 52.5*TMath::DegToRad()))||
 377             ((127.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 142.5*TMath::DegToRad()))||
 378             ((217.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 232.5*TMath::DegToRad()))||
 379             ((307.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 322.5*TMath::DegToRad())))
 380       gPsiMinusPhiBin = 1.0;
 381     //out of plane
 382     else if(((82.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 97.5*TMath::DegToRad()))||
 383             ((262.5*TMath::DegToRad() <= gPsiMinusPhi)&&(gPsiMinusPhi <= 277.5*TMath::DegToRad())))
 384       gPsiMinusPhiBin = 2.0;
 385     //everything else
 386     else
 387       gPsiMinusPhiBin = 3.0;
 388
 389     fHistPsiMinusPhi->Fill(gPsiMinusPhiBin,gPsiMinusPhi);
 390
 391     Short_t  charge1 = (Short_t) firstParticle->Charge();
 392
 393     trackVariablesSingle[0]    =  gPsiMinusPhiBin;
 394     trackVariablesSingle[1]    =  firstPt;
 395       if(fEventClass=="Multiplicity" || fEventClass == "Centrality" ) trackVariablesSingle[0] = kMultorCent;
 396
 397     //fill single particle histograms
 398     if(charge1 > 0)      fHistP->Fill(trackVariablesSingle,0,firstCorrection); //==========================correction
 399     else if(charge1 < 0) fHistN->Fill(trackVariablesSingle,0,firstCorrection);  //==========================correction
 400
 401     // 2nd particle loop
 402     for(Int_t j = 0; j < jMax; j++) {
 403
 404       if(!particlesMixed && j == i) continue; // no auto correlations (only for non mixing)
 405
 406       Short_t charge2 = secondCharge[j];
 407
 408       trackVariablesPair[0]    =  trackVariablesSingle[0];
 409       trackVariablesPair[1]    =  firstEta - secondEta[j];  // delta eta
 410       trackVariablesPair[2]    =  firstPhi - secondPhi[j];  // delta phi
 411       //if (trackVariablesPair[2] > 180.)   // delta phi between -180 and 180
 412       //trackVariablesPair[2] -= 360.;
 413       //if (trackVariablesPair[2] <  - 180.)
 414       //trackVariablesPair[2] += 360.;
 415       if (trackVariablesPair[2] > TMath::Pi()) // delta phi between -pi and pi
 416         trackVariablesPair[2] -= 2.*TMath::Pi();
 417       if (trackVariablesPair[2] <  - TMath::Pi())
 418         trackVariablesPair[2] += 2.*TMath::Pi();
 419       if (trackVariablesPair[2] <  - TMath::Pi()/2.)
 420       trackVariablesPair[2] += 2.*TMath::Pi();
 421
 422       trackVariablesPair[3]    =  firstPt;      // pt trigger
 423       trackVariablesPair[4]    =  secondPt[j];  // pt
 424       //        trackVariablesPair[5]    =  fCentrality;  // centrality
 425
 426       // HBT like cut
 427       if(fHBTCut && charge1 * charge2 > 0){
 428         //if( dphi < 3 || deta < 0.01 ){   // VERSION 1
 429         //  continue;
 430
 431         Double_t deta = firstEta - secondEta[j];
 432         Double_t dphi = firstPhi - secondPhi[j];
 433         // VERSION 2 (Taken from DPhiCorrelations)
 434         // the variables & cuthave been developed by the HBT group
 435         // see e.g. https://indico.cern.ch/materialDisplay.py?contribId=36&sessionId=6&materialId=slides&confId=142700
 436         fHistHBTbefore->Fill(deta,dphi);
 437
 438         // optimization
 439         if (TMath::Abs(deta) < 0.02 * 2.5 * 3) //twoTrackEfficiencyCutValue = 0.02 [default for dphicorrelations]
 440           {
 441             // phi in rad
 442             //Float_t phi1rad = firstPhi*TMath::DegToRad();
 443             //Float_t phi2rad = secondPhi[j]*TMath::DegToRad();
 444             Float_t phi1rad = firstPhi;
 445             Float_t phi2rad = secondPhi[j];
 446
 447             // check first boundaries to see if is worth to loop and find the minimum
 448             Float_t dphistar1 = GetDPhiStar(phi1rad, firstPt, charge1, phi2rad, secondPt[j], charge2, 0.8, bSign);
 449             Float_t dphistar2 = GetDPhiStar(phi1rad, firstPt, charge1, phi2rad, secondPt[j], charge2, 2.5, bSign);
 450
 451             const Float_t kLimit = 0.02 * 3;
 452
 453             Float_t dphistarminabs = 1e5;
 454             Float_t dphistarmin = 1e5;
 455
 456             if (TMath::Abs(dphistar1) < kLimit || TMath::Abs(dphistar2) < kLimit || dphistar1 * dphistar2 < 0 ) {
 457               for (Double_t rad=0.8; rad<2.51; rad+=0.01) {
 458                 Float_t dphistar = GetDPhiStar(phi1rad, firstPt, charge1, phi2rad, secondPt[j], charge2, rad, bSign);
 459                 Float_t dphistarabs = TMath::Abs(dphistar);
 460
 461                 if (dphistarabs < dphistarminabs) {
 462                   dphistarmin = dphistar;
 463                   dphistarminabs = dphistarabs;
 464                 }
 465               }
 466
 467               if (dphistarminabs < 0.02 && TMath::Abs(deta) < 0.02) {
 468                 //AliInfo(Form("HBT: Removed track pair %d %d with [[%f %f]] %f %f %f | %f %f %d %f %f %d %f", i, j, deta, dphi, dphistarminabs, dphistar1, dphistar2, phi1rad, pt1, charge1, phi2rad, pt2, charge2, bSign));
 469                 continue;
 470               }
 471             }
 472           }
 473         fHistHBTafter->Fill(deta,dphi);
 474       }//HBT cut
 475
 476       // conversions
 477       if(fConversionCut) {
 478         if (charge1 * charge2 < 0) {
 479           Double_t deta = firstEta - secondEta[j];
 480           Double_t dphi = firstPhi - secondPhi[j];
 481           fHistConversionbefore->Fill(deta,dphi);
 482
 483           Float_t m0 = 0.510e-3;
 484           Float_t tantheta1 = 1e10;
 485
 486           // phi in rad
 487           //Float_t phi1rad = firstPhi*TMath::DegToRad();
 488           //Float_t phi2rad = secondPhi[j]*TMath::DegToRad();
 489           Float_t phi1rad = firstPhi;
 490           Float_t phi2rad = secondPhi[j];
 491
 492           if (firstEta < -1e-10 || firstEta > 1e-10)
 493             tantheta1 = 2 * TMath::Exp(-firstEta) / ( 1 - TMath::Exp(-2*firstEta));
 494
 495           Float_t tantheta2 = 1e10;
 496           if (secondEta[j] < -1e-10 || secondEta[j] > 1e-10)
 497             tantheta2 = 2 * TMath::Exp(-secondEta[j]) / ( 1 - TMath::Exp(-2*secondEta[j]));
 498
 499           Float_t e1squ = m0 * m0 + firstPt * firstPt * (1.0 + 1.0 / tantheta1 / tantheta1);
 500           Float_t e2squ = m0 * m0 + secondPt[j] * secondPt[j] * (1.0 + 1.0 / tantheta2 / tantheta2);
 501
 502           Float_t masssqu = 2 * m0 * m0 + 2 * ( TMath::Sqrt(e1squ * e2squ) - ( firstPt * secondPt[j] * ( TMath::Cos(phi1rad - phi2rad) + 1.0 / tantheta1 / tantheta2 ) ) );
 503
 504           if (masssqu < 0.04*0.04){
 505             //AliInfo(Form("Conversion: Removed track pair %d %d with [[%f %f] %f %f] %d %d <- %f %f  %f %f   %f %f ", i, j, deta, dphi, masssqu, charge1, charge2,eta1,eta2,phi1,phi2,pt1,pt2));
 506             continue;
 507           }
 508           fHistConversionafter->Fill(deta,dphi);
 509         }
 510       }//conversion cut
 511
 512       if( charge1 > 0 && charge2 < 0)  fHistPN->Fill(trackVariablesPair,0,firstCorrection*secondCorrection[j]); //==========================correction
 513       else if( charge1 < 0 && charge2 > 0)  fHistNP->Fill(trackVariablesPair,0,firstCorrection*secondCorrection[j]);//==========================correction
 514       else if( charge1 > 0 && charge2 > 0)  fHistPP->Fill(trackVariablesPair,0,firstCorrection*secondCorrection[j]);//==========================correction
 515       else if( charge1 < 0 && charge2 < 0)  fHistNN->Fill(trackVariablesPair,0,firstCorrection*secondCorrection[j]);//==========================correction
 516       else {
 517         //AliWarning(Form("Wrong charge combination: charge1 = %d and charge2 = %d",charge,charge2));
 518         continue;
 519       }
 520     }//end of 2nd particle loop
 521   }//end of 1st particle loop
 522 }
 523
 524 //____________________________________________________________________//
 525 TH1D *AliBalancePsi::GetBalanceFunctionHistogram(Int_t iVariableSingle,
 526                                                  Int_t iVariablePair,
 527                                                  Double_t psiMin,
 528                                                  Double_t psiMax,
 529                                                  Double_t ptTriggerMin,
 530                                                  Double_t ptTriggerMax,
 531                                                  Double_t ptAssociatedMin,
 532                                                  Double_t ptAssociatedMax) {
 533   //Returns the BF histogram, extracted from the 6 AliTHn objects
 534   //(private members) of the AliBalancePsi class.
 535   //iVariableSingle: 0(phi-Psi), 1(pt-trigger)
 536   //iVariablePair: 0(phi-Psi) 1(Delta eta), 2(Delta phi), 3(pt-trigger), 4(pt-associated
 537   // Psi_2
 538   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 539   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 540   fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 541   fHistNP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 542   fHistPP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 543   fHistNN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 544
 545   // pt trigger
 546   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
 547     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 548     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 549     fHistPN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 550     fHistNP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 551     fHistPP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 552     fHistNN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 553   }
 554
 555   // pt associated
 556   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.)) {
 557     fHistPN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 558     fHistNP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 559     fHistPP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 560     fHistNN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 561   }
 562
 563   //Printf("P:%lf - N:%lf - PN:%lf - NP:%lf - PP:%lf - NN:%lf",fHistP->GetEntries(0),fHistN->GetEntries(0),fHistPN->GetEntries(0),fHistNP->GetEntries(0),fHistPP->GetEntries(0),fHistNN->GetEntries(0));
 564
 565   // Project into the wanted space (1st: analysis step, 2nd: axis)
 566   TH1D* hTemp1 = (TH1D*)fHistPN->Project(0,iVariablePair);
 567   TH1D* hTemp2 = (TH1D*)fHistNP->Project(0,iVariablePair);
 568   TH1D* hTemp3 = (TH1D*)fHistPP->Project(0,iVariablePair);
 569   TH1D* hTemp4 = (TH1D*)fHistNN->Project(0,iVariablePair);
 570   TH1D* hTemp5 = (TH1D*)fHistP->Project(0,iVariableSingle);
 571   TH1D* hTemp6 = (TH1D*)fHistN->Project(0,iVariableSingle);
 572
 573   TH1D *gHistBalanceFunctionHistogram = 0x0;
 574   if((hTemp1)&&(hTemp2)&&(hTemp3)&&(hTemp4)&&(hTemp5)&&(hTemp6)) {
 575     gHistBalanceFunctionHistogram = (TH1D*)hTemp1->Clone();
 576     gHistBalanceFunctionHistogram->Reset();
 577
 578     switch(iVariablePair) {
 579     case 1:
 580       gHistBalanceFunctionHistogram->GetXaxis()->SetTitle("#Delta#eta");
 581       gHistBalanceFunctionHistogram->GetYaxis()->SetTitle("B(#Delta#eta)");
 582       break;
 583     case 2:
 584       gHistBalanceFunctionHistogram->GetXaxis()->SetTitle("#Delta#varphi (rad)");
 585       gHistBalanceFunctionHistogram->GetYaxis()->SetTitle("B(#Delta#varphi)");
 586       break;
 587     default:
 588       break;
 589     }
 590
 591     hTemp1->Sumw2();
 592     hTemp2->Sumw2();
 593     hTemp3->Sumw2();
 594     hTemp4->Sumw2();
 595     hTemp1->Add(hTemp3,-1.);
 596     hTemp1->Scale(1./hTemp5->GetEntries());
 597     hTemp2->Add(hTemp4,-1.);
 598     hTemp2->Scale(1./hTemp6->GetEntries());
 599     gHistBalanceFunctionHistogram->Add(hTemp1,hTemp2,1.,1.);
 600     gHistBalanceFunctionHistogram->Scale(0.5);
 601
 602     //normalize to bin width
 603     gHistBalanceFunctionHistogram->Scale(1./((Double_t)gHistBalanceFunctionHistogram->GetXaxis()->GetBinWidth(1)*(Double_t)gHistBalanceFunctionHistogram->GetYaxis()->GetBinWidth(1)));
 604   }
 605
 606   return gHistBalanceFunctionHistogram;
 607 }
 608
 609 //____________________________________________________________________//
 610 TH1D *AliBalancePsi::GetBalanceFunctionHistogram2pMethod(Int_t iVariableSingle,
 611                                                          Int_t iVariablePair,
 612                                                          Double_t psiMin,
 613                                                          Double_t psiMax,
 614                                                          Double_t ptTriggerMin,
 615                                                          Double_t ptTriggerMax,
 616                                                          Double_t ptAssociatedMin,
 617                                                          Double_t ptAssociatedMax,
 618                                                          AliBalancePsi *bfMix) {
 619   //Returns the BF histogram, extracted from the 6 AliTHn objects
 620   //after dividing each correlation function by the Event Mixing one
 621   //(private members) of the AliBalancePsi class.
 622   //iVariableSingle: 0(phi-Psi), 1(pt-trigger)
 623   //iVariablePair: 0(phi-Psi) 1(Delta eta), 2(Delta phi), 3(pt-trigger), 4(pt-associated
 624   // Psi_2
 625   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 626   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 627   fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 628   fHistNP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 629   fHistPP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 630   fHistNN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 631
 632   // pt trigger
 633   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
 634     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 635     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 636     fHistPN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 637     fHistNP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 638     fHistPP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 639     fHistNN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 640   }
 641
 642   // pt associated
 643   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.)) {
 644     fHistPN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 645     fHistNP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 646     fHistPP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 647     fHistNN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 648   }
 649
 650   // ============================================================================================
 651   // the same for event mixing
 652   AliTHn *fHistPMix = bfMix->GetHistNp();
 653   AliTHn *fHistNMix = bfMix->GetHistNn();
 654   AliTHn *fHistPNMix = bfMix->GetHistNpn();
 655   AliTHn *fHistNPMix = bfMix->GetHistNnp();
 656   AliTHn *fHistPPMix = bfMix->GetHistNpp();
 657   AliTHn *fHistNNMix = bfMix->GetHistNnn();
 658
 659   // Psi_2
 660   fHistPMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 661   fHistNMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 662   fHistPNMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 663   fHistNPMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 664   fHistPPMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 665   fHistNNMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 666
 667   // pt trigger
 668   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
 669     fHistPMix->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 670     fHistNMix->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 671     fHistPNMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 672     fHistNPMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 673     fHistPPMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 674     fHistNNMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 675   }
 676
 677   // pt associated
 678   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.)) {
 679     fHistPNMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 680     fHistNPMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 681     fHistPPMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 682     fHistNNMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 683   }
 684   // ============================================================================================
 685
 686   //Printf("P:%lf - N:%lf - PN:%lf - NP:%lf - PP:%lf - NN:%lf",fHistP->GetEntries(0),fHistN->GetEntries(0),fHistPN->GetEntries(0),fHistNP->GetEntries(0),fHistPP->GetEntries(0),fHistNN->GetEntries(0));
 687
 688   // Project into the wanted space (1st: analysis step, 2nd: axis)
 689   TH1D* hTemp1 = (TH1D*)fHistPN->Project(0,iVariablePair);
 690   TH1D* hTemp2 = (TH1D*)fHistNP->Project(0,iVariablePair);
 691   TH1D* hTemp3 = (TH1D*)fHistPP->Project(0,iVariablePair);
 692   TH1D* hTemp4 = (TH1D*)fHistNN->Project(0,iVariablePair);
 693   TH1D* hTemp5 = (TH1D*)fHistP->Project(0,iVariableSingle);
 694   TH1D* hTemp6 = (TH1D*)fHistN->Project(0,iVariableSingle);
 695
 696   // ============================================================================================
 697   // the same for event mixing
 698   TH2D* hTemp1Mix = (TH2D*)fHistPNMix->Project(0,iVariablePair);
 699   TH2D* hTemp2Mix = (TH2D*)fHistNPMix->Project(0,iVariablePair);
 700   TH2D* hTemp3Mix = (TH2D*)fHistPPMix->Project(0,iVariablePair);
 701   TH2D* hTemp4Mix = (TH2D*)fHistNNMix->Project(0,iVariablePair);
 702   TH1D* hTemp5Mix = (TH1D*)fHistPMix->Project(0,iVariableSingle);
 703   TH1D* hTemp6Mix = (TH1D*)fHistNMix->Project(0,iVariableSingle);
 704   // ============================================================================================
 705
 706   TH1D *gHistBalanceFunctionHistogram = 0x0;
 707   if((hTemp1)&&(hTemp2)&&(hTemp3)&&(hTemp4)&&(hTemp5)&&(hTemp6)) {
 708     gHistBalanceFunctionHistogram = (TH1D*)hTemp1->Clone();
 709     gHistBalanceFunctionHistogram->Reset();
 710
 711     switch(iVariablePair) {
 712     case 1:
 713       gHistBalanceFunctionHistogram->GetXaxis()->SetTitle("#Delta#eta");
 714       gHistBalanceFunctionHistogram->GetYaxis()->SetTitle("B(#Delta#eta)");
 715       break;
 716     case 2:
 717       gHistBalanceFunctionHistogram->GetXaxis()->SetTitle("#Delta#varphi (rad)");
 718       gHistBalanceFunctionHistogram->GetYaxis()->SetTitle("B(#Delta#varphi)");
 719       break;
 720     default:
 721       break;
 722     }
 723
 724     hTemp1->Sumw2();
 725     hTemp2->Sumw2();
 726     hTemp3->Sumw2();
 727     hTemp4->Sumw2();
 728     hTemp1Mix->Sumw2();
 729     hTemp2Mix->Sumw2();
 730     hTemp3Mix->Sumw2();
 731     hTemp4Mix->Sumw2();
 732
 733     hTemp1->Scale(1./hTemp5->GetEntries());
 734     hTemp3->Scale(1./hTemp5->GetEntries());
 735     hTemp2->Scale(1./hTemp6->GetEntries());
 736     hTemp4->Scale(1./hTemp6->GetEntries());
 737     hTemp1Mix->Scale(1./hTemp5Mix->GetEntries());
 738     hTemp3Mix->Scale(1./hTemp5Mix->GetEntries());
 739     hTemp2Mix->Scale(1./hTemp6Mix->GetEntries());
 740     hTemp4Mix->Scale(1./hTemp6Mix->GetEntries());
 741
 742     hTemp1->Divide(hTemp1Mix);
 743     hTemp2->Divide(hTemp2Mix);
 744     hTemp3->Divide(hTemp3Mix);
 745     hTemp4->Divide(hTemp4Mix);
 746
 747     hTemp1->Add(hTemp3,-1.);
 748     hTemp2->Add(hTemp4,-1.);
 749
 750     gHistBalanceFunctionHistogram->Add(hTemp1,hTemp2,1.,1.);
 751     gHistBalanceFunctionHistogram->Scale(0.5);
 752
 753     //normalize to bin width
 754     gHistBalanceFunctionHistogram->Scale(1./((Double_t)gHistBalanceFunctionHistogram->GetXaxis()->GetBinWidth(1)*(Double_t)gHistBalanceFunctionHistogram->GetYaxis()->GetBinWidth(1)));
 755   }
 756
 757   return gHistBalanceFunctionHistogram;
 758 }
 759
 760 //____________________________________________________________________//
 761 TH2D *AliBalancePsi::GetBalanceFunctionDeltaEtaDeltaPhi(Double_t psiMin,
 762                                                         Double_t psiMax,
 763                                                         Double_t ptTriggerMin,
 764                                                         Double_t ptTriggerMax,
 765                                                         Double_t ptAssociatedMin,
 766                                                         Double_t ptAssociatedMax) {
 767   //Returns the BF histogram in Delta eta vs Delta phi,
 768   //extracted from the 6 AliTHn objects
 769   //(private members) of the AliBalancePsi class.
 770   //iVariableSingle: 0(phi-Psi), 1(pt-trigger)
 771   //iVariablePair: 0(phi-Psi) 1(Delta eta), 2(Delta phi), 3(pt-trigger), 4(pt-associated
 772   TString histName = "gHistBalanceFunctionHistogram2D";
 773
 774   // Psi_2
 775   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 776   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 777   fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 778   fHistNP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 779   fHistPP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 780   fHistNN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 781
 782   // pt trigger
 783   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
 784     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 785     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 786     fHistPN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 787     fHistNP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 788     fHistPP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 789     fHistNN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 790   }
 791
 792   // pt associated
 793   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.)) {
 794     fHistPN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 795     fHistNP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 796     fHistPP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 797     fHistNN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 798   }
 799
 800   //AliInfo(Form("P:%lf - N:%lf - PN:%lf - NP:%lf - PP:%lf - NN:%lf",fHistP->GetEntries(0),fHistN->GetEntries(0),fHistPN->GetEntries(0),fHistNP->GetEntries(0),fHistPP->GetEntries(0),fHistNN->GetEntries(0)));
 801
 802   // Project into the wanted space (1st: analysis step, 2nd: axis)
 803   TH2D* hTemp1 = (TH2D*)fHistPN->Project(0,1,2);
 804   TH2D* hTemp2 = (TH2D*)fHistNP->Project(0,1,2);
 805   TH2D* hTemp3 = (TH2D*)fHistPP->Project(0,1,2);
 806   TH2D* hTemp4 = (TH2D*)fHistNN->Project(0,1,2);
 807   TH1D* hTemp5 = (TH1D*)fHistP->Project(0,1);
 808   TH1D* hTemp6 = (TH1D*)fHistN->Project(0,1);
 809
 810   TH2D *gHistBalanceFunctionHistogram = 0x0;
 811   if((hTemp1)&&(hTemp2)&&(hTemp3)&&(hTemp4)&&(hTemp5)&&(hTemp6)) {
 812     gHistBalanceFunctionHistogram = (TH2D*)hTemp1->Clone();
 813     gHistBalanceFunctionHistogram->Reset();
 814     gHistBalanceFunctionHistogram->GetXaxis()->SetTitle("#Delta#eta");
 815     gHistBalanceFunctionHistogram->GetYaxis()->SetTitle("#Delta#varphi (rad)");
 816     gHistBalanceFunctionHistogram->GetZaxis()->SetTitle("B(#Delta#eta,#Delta#varphi)");
 817
 818     hTemp1->Sumw2();
 819     hTemp2->Sumw2();
 820     hTemp3->Sumw2();
 821     hTemp4->Sumw2();
 822     hTemp1->Add(hTemp3,-1.);
 823     hTemp1->Scale(1./hTemp5->GetEntries());
 824     hTemp2->Add(hTemp4,-1.);
 825     hTemp2->Scale(1./hTemp6->GetEntries());
 826     gHistBalanceFunctionHistogram->Add(hTemp1,hTemp2,1.,1.);
 827     gHistBalanceFunctionHistogram->Scale(0.5);
 828
 829     //normalize to bin width
 830     gHistBalanceFunctionHistogram->Scale(1./((Double_t)gHistBalanceFunctionHistogram->GetXaxis()->GetBinWidth(1)*(Double_t)gHistBalanceFunctionHistogram->GetYaxis()->GetBinWidth(1)));
 831   }
 832
 833   return gHistBalanceFunctionHistogram;
 834 }
 835
 836 //____________________________________________________________________//
 837 TH2D *AliBalancePsi::GetBalanceFunctionDeltaEtaDeltaPhi2pMethod(Double_t psiMin,
 838                                                                 Double_t psiMax,
 839                                                                 Double_t ptTriggerMin,
 840                                                                 Double_t ptTriggerMax,
 841                                                                 Double_t ptAssociatedMin,
 842                                                                 Double_t ptAssociatedMax,
 843                                                                 AliBalancePsi *bfMix) {
 844   //Returns the BF histogram in Delta eta vs Delta phi,
 845   //after dividing each correlation function by the Event Mixing one
 846   //extracted from the 6 AliTHn objects
 847   //(private members) of the AliBalancePsi class.
 848   //iVariableSingle: 0(phi-Psi), 1(pt-trigger)
 849   //iVariablePair: 0(phi-Psi) 1(Delta eta), 2(Delta phi), 3(pt-trigger), 4(pt-associated
 850   TString histName = "gHistBalanceFunctionHistogram2D";
 851
 852   if(!bfMix){
 853     AliError("balance function object for event mixing not available");
 854     return NULL;
 855   }
 856
 857   // Psi_2
 858   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 859   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 860   fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 861   fHistNP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 862   fHistPP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 863   fHistNN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 864
 865   // pt trigger
 866   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
 867     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 868     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 869     fHistPN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 870     fHistNP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 871     fHistPP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 872     fHistNN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 873   }
 874
 875   // pt associated
 876   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.)) {
 877     fHistPN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 878     fHistNP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 879     fHistPP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 880     fHistNN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 881   }
 882
 883
 884   // ============================================================================================
 885   // the same for event mixing
 886   AliTHn *fHistPMix = bfMix->GetHistNp();
 887   AliTHn *fHistNMix = bfMix->GetHistNn();
 888   AliTHn *fHistPNMix = bfMix->GetHistNpn();
 889   AliTHn *fHistNPMix = bfMix->GetHistNnp();
 890   AliTHn *fHistPPMix = bfMix->GetHistNpp();
 891   AliTHn *fHistNNMix = bfMix->GetHistNnn();
 892
 893   // Psi_2
 894   fHistPMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 895   fHistNMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 896   fHistPNMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 897   fHistNPMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 898   fHistPPMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 899   fHistNNMix->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 900
 901   // pt trigger
 902   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
 903     fHistPMix->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 904     fHistNMix->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 905     fHistPNMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 906     fHistNPMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 907     fHistPPMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 908     fHistNNMix->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
 909   }
 910
 911   // pt associated
 912   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.)) {
 913     fHistPNMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 914     fHistNPMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 915     fHistPPMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 916     fHistNNMix->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
 917   }
 918   // ============================================================================================
 919
 920
 921   //AliInfo(Form("P:%lf - N:%lf - PN:%lf - NP:%lf - PP:%lf - NN:%lf",fHistP->GetEntries(0),fHistN->GetEntries(0),fHistPN->GetEntries(0),fHistNP->GetEntries(0),fHistPP->GetEntries(0),fHistNN->GetEntries(0)));
 922
 923   // Project into the wanted space (1st: analysis step, 2nd: axis)
 924   TH2D* hTemp1 = (TH2D*)fHistPN->Project(0,1,2);
 925   TH2D* hTemp2 = (TH2D*)fHistNP->Project(0,1,2);
 926   TH2D* hTemp3 = (TH2D*)fHistPP->Project(0,1,2);
 927   TH2D* hTemp4 = (TH2D*)fHistNN->Project(0,1,2);
 928   TH1D* hTemp5 = (TH1D*)fHistP->Project(0,1);
 929   TH1D* hTemp6 = (TH1D*)fHistN->Project(0,1);
 930
 931   // ============================================================================================
 932   // the same for event mixing
 933   TH2D* hTemp1Mix = (TH2D*)fHistPNMix->Project(0,1,2);
 934   TH2D* hTemp2Mix = (TH2D*)fHistNPMix->Project(0,1,2);
 935   TH2D* hTemp3Mix = (TH2D*)fHistPPMix->Project(0,1,2);
 936   TH2D* hTemp4Mix = (TH2D*)fHistNNMix->Project(0,1,2);
 937   TH1D* hTemp5Mix = (TH1D*)fHistPMix->Project(0,1);
 938   TH1D* hTemp6Mix = (TH1D*)fHistNMix->Project(0,1);
 939   // ============================================================================================
 940
 941   TH2D *gHistBalanceFunctionHistogram = 0x0;
 942   if((hTemp1)&&(hTemp2)&&(hTemp3)&&(hTemp4)&&(hTemp5)&&(hTemp6)) {
 943     gHistBalanceFunctionHistogram = (TH2D*)hTemp1->Clone();
 944     gHistBalanceFunctionHistogram->Reset();
 945     gHistBalanceFunctionHistogram->GetXaxis()->SetTitle("#Delta#eta");
 946     gHistBalanceFunctionHistogram->GetYaxis()->SetTitle("#Delta#varphi (rad)");
 947     gHistBalanceFunctionHistogram->GetZaxis()->SetTitle("B(#Delta#eta,#Delta#varphi)");
 948
 949     hTemp1->Sumw2();
 950     hTemp2->Sumw2();
 951     hTemp3->Sumw2();
 952     hTemp4->Sumw2();
 953     hTemp1Mix->Sumw2();
 954     hTemp2Mix->Sumw2();
 955     hTemp3Mix->Sumw2();
 956     hTemp4Mix->Sumw2();
 957
 958     hTemp1->Scale(1./hTemp5->GetEntries());
 959     hTemp3->Scale(1./hTemp5->GetEntries());
 960     hTemp2->Scale(1./hTemp6->GetEntries());
 961     hTemp4->Scale(1./hTemp6->GetEntries());
 962     hTemp1Mix->Scale(1./hTemp5Mix->GetEntries());
 963     hTemp3Mix->Scale(1./hTemp5Mix->GetEntries());
 964     hTemp2Mix->Scale(1./hTemp6Mix->GetEntries());
 965     hTemp4Mix->Scale(1./hTemp6Mix->GetEntries());
 966
 967     hTemp1->Divide(hTemp1Mix);
 968     hTemp2->Divide(hTemp2Mix);
 969     hTemp3->Divide(hTemp3Mix);
 970     hTemp4->Divide(hTemp4Mix);
 971
 972     hTemp1->Add(hTemp3,-1.);
 973     hTemp2->Add(hTemp4,-1.);
 974
 975     gHistBalanceFunctionHistogram->Add(hTemp1,hTemp2,1.,1.);
 976     gHistBalanceFunctionHistogram->Scale(0.5);
 977
 978     //normalize to bin width
 979     gHistBalanceFunctionHistogram->Scale(1./((Double_t)gHistBalanceFunctionHistogram->GetXaxis()->GetBinWidth(1)*(Double_t)gHistBalanceFunctionHistogram->GetYaxis()->GetBinWidth(1)));
 980   }
 981
 982   return gHistBalanceFunctionHistogram;
 983 }
 984
 985
 986 //____________________________________________________________________//
 987 TH2D *AliBalancePsi::GetCorrelationFunctionPN(Double_t psiMin,
 988                                               Double_t psiMax,
 989                                               Double_t ptTriggerMin,
 990                                               Double_t ptTriggerMax,
 991                                               Double_t ptAssociatedMin,
 992                                               Double_t ptAssociatedMax) {
 993   //Returns the 2D correlation function for (+-) pairs
 994   // Psi_2: axis 0
 995   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 996   fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
 997
 998   // pt trigger
 999   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
1000     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1001     fHistPN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1002   }
1003
1004   // pt associated
1005   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.))
1006     fHistPN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1007
1008   //fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(-0.5,2.5);
1009   //fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(-0.5,2.5);
1010
1011   //TH2D *gHistTest = dynamic_cast<TH2D *>(fHistP->Project(0,0,1));
1012   //TCanvas *c1 = new TCanvas("c1","");
1013   //c1->cd();
1014   //if(!gHistTest){
1015   //AliError("Projection of fHistP = NULL");
1016   //return gHistTest;
1017   //}
1018   //else{
1019   //gHistTest->DrawCopy("colz");
1020   //}
1021
1022   //0:step, 1: Delta eta, 2: Delta phi
1023   TH2D *gHist = dynamic_cast<TH2D *>(fHistPN->Project(0,1,2));
1024   if(!gHist){
1025     AliError("Projection of fHistPN = NULL");
1026     return gHist;
1027   }
1028
1029   //AliInfo(Form("Entries (test): %lf",(Double_t)(gHistTest->GetEntries())));
1030   //AliInfo(Form("Entries (1D): %lf",(Double_t)(fHistP->Project(0,1)->GetEntries())));
1031   //AliInfo(Form("Entries (2D): %lf",(Double_t)(fHistPN->Project(0,1,2)->GetEntries())));
1032
1033   //TCanvas *c2 = new TCanvas("c2","");
1034   //c2->cd();
1035   //fHistPN->Project(0,1,2)->DrawCopy("colz");
1036
1037   if((Double_t)(fHistP->Project(0,1)->GetEntries())!=0)
1038     gHist->Scale(1./(Double_t)(fHistP->Project(0,1)->GetEntries()));
1039
1040   //normalize to bin width
1041   gHist->Scale(1./((Double_t)gHist->GetXaxis()->GetBinWidth(1)*(Double_t)gHist->GetYaxis()->GetBinWidth(1)));
1042
1043   return gHist;
1044 }
1045
1046 //____________________________________________________________________//
1047 TH2D *AliBalancePsi::GetCorrelationFunctionNP(Double_t psiMin,
1048                                               Double_t psiMax,
1049                                               Double_t ptTriggerMin,
1050                                               Double_t ptTriggerMax,
1051                                               Double_t ptAssociatedMin,
1052                                               Double_t ptAssociatedMax) {
1053   //Returns the 2D correlation function for (+-) pairs
1054   // Psi_2: axis 0
1055   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1056   fHistNP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1057
1058   // pt trigger
1059   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
1060     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1061     fHistNP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1062   }
1063
1064   // pt associated
1065   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.))
1066     fHistNP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1067
1068   //0:step, 1: Delta eta, 2: Delta phi
1069   TH2D *gHist = dynamic_cast<TH2D *>(fHistNP->Project(0,1,2));
1070   if(!gHist){
1071     AliError("Projection of fHistPN = NULL");
1072     return gHist;
1073   }
1074
1075   //Printf("Entries (1D): %lf",(Double_t)(fHistN->Project(0,2)->GetEntries()));
1076   //Printf("Entries (2D): %lf",(Double_t)(fHistNP->Project(0,2,3)->GetEntries()));
1077   if((Double_t)(fHistN->Project(0,1)->GetEntries())!=0)
1078     gHist->Scale(1./(Double_t)(fHistN->Project(0,1)->GetEntries()));
1079
1080   //normalize to bin width
1081   gHist->Scale(1./((Double_t)gHist->GetXaxis()->GetBinWidth(1)*(Double_t)gHist->GetYaxis()->GetBinWidth(1)));
1082
1083   return gHist;
1084 }
1085
1086 //____________________________________________________________________//
1087 TH2D *AliBalancePsi::GetCorrelationFunctionPP(Double_t psiMin,
1088                                               Double_t psiMax,
1089                                               Double_t ptTriggerMin,
1090                                               Double_t ptTriggerMax,
1091                                               Double_t ptAssociatedMin,
1092                                               Double_t ptAssociatedMax) {
1093   //Returns the 2D correlation function for (+-) pairs
1094   // Psi_2: axis 0
1095   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1096   fHistPP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1097
1098   // pt trigger
1099   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
1100     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1101     fHistPP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1102   }
1103
1104   // pt associated
1105   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.))
1106     fHistPP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1107
1108   //0:step, 1: Delta eta, 2: Delta phi
1109   TH2D *gHist = dynamic_cast<TH2D *>(fHistPP->Project(0,1,2));
1110   if(!gHist){
1111     AliError("Projection of fHistPN = NULL");
1112     return gHist;
1113   }
1114
1115   //Printf("Entries (1D): %lf",(Double_t)(fHistP->Project(0,2)->GetEntries()));
1116   //Printf("Entries (2D): %lf",(Double_t)(fHistPP->Project(0,2,3)->GetEntries()));
1117   if((Double_t)(fHistP->Project(0,1)->GetEntries())!=0)
1118     gHist->Scale(1./(Double_t)(fHistP->Project(0,1)->GetEntries()));
1119
1120   //normalize to bin width
1121   gHist->Scale(1./((Double_t)gHist->GetXaxis()->GetBinWidth(1)*(Double_t)gHist->GetYaxis()->GetBinWidth(1)));
1122
1123   return gHist;
1124 }
1125
1126 //____________________________________________________________________//
1127 TH2D *AliBalancePsi::GetCorrelationFunctionNN(Double_t psiMin,
1128                                               Double_t psiMax,
1129                                               Double_t ptTriggerMin,
1130                                               Double_t ptTriggerMax,
1131                                               Double_t ptAssociatedMin,
1132                                               Double_t ptAssociatedMax) {
1133   //Returns the 2D correlation function for (+-) pairs
1134   // Psi_2: axis 0
1135   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1136   fHistNN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1137
1138   // pt trigger
1139   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
1140     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1141     fHistNN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1142   }
1143
1144   // pt associated
1145   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.))
1146     fHistNN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1147
1148   //0:step, 1: Delta eta, 2: Delta phi
1149   TH2D *gHist = dynamic_cast<TH2D *>(fHistNN->Project(0,1,2));
1150   if(!gHist){
1151     AliError("Projection of fHistPN = NULL");
1152     return gHist;
1153   }
1154
1155   //Printf("Entries (1D): %lf",(Double_t)(fHistN->Project(0,2)->GetEntries()));
1156   //Printf("Entries (2D): %lf",(Double_t)(fHistNN->Project(0,2,3)->GetEntries()));
1157   if((Double_t)(fHistN->Project(0,1)->GetEntries())!=0)
1158     gHist->Scale(1./(Double_t)(fHistN->Project(0,1)->GetEntries()));
1159
1160   //normalize to bin width
1161   gHist->Scale(1./((Double_t)gHist->GetXaxis()->GetBinWidth(1)*(Double_t)gHist->GetYaxis()->GetBinWidth(1)));
1162
1163   return gHist;
1164 }
1165
1166 //____________________________________________________________________//
1167 TH2D *AliBalancePsi::GetCorrelationFunctionChargeIndependent(Double_t psiMin,
1168                                                              Double_t psiMax,
1169                                                              Double_t ptTriggerMin,
1170                                                              Double_t ptTriggerMax,
1171                                                              Double_t ptAssociatedMin,
1172                                                              Double_t ptAssociatedMax) {
1173   //Returns the 2D correlation function for the sum of all charge combination pairs
1174   // Psi_2: axis 0
1175   fHistN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1176   fHistP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1177   fHistNN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1178   fHistPP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1179   fHistNP->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1180   fHistPN->GetGrid(0)->GetGrid()->GetAxis(0)->SetRangeUser(psiMin,psiMax);
1181
1182   // pt trigger
1183   if((ptTriggerMin != -1.)&&(ptTriggerMax != -1.)) {
1184     fHistN->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1185     fHistP->GetGrid(0)->GetGrid()->GetAxis(1)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1186     fHistNN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1187     fHistPP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1188     fHistNP->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1189     fHistPN->GetGrid(0)->GetGrid()->GetAxis(3)->SetRangeUser(ptTriggerMin,ptTriggerMax);
1190   }
1191
1192   // pt associated
1193   if((ptAssociatedMin != -1.)&&(ptAssociatedMax != -1.))
1194     fHistNN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1195     fHistPP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1196     fHistNP->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1197     fHistPN->GetGrid(0)->GetGrid()->GetAxis(4)->SetRangeUser(ptAssociatedMin,ptAssociatedMax);
1198
1199   //0:step, 1: Delta eta, 2: Delta phi
1200   TH2D *gHistNN = dynamic_cast<TH2D *>(fHistNN->Project(0,1,2));
1201   if(!gHistNN){
1202     AliError("Projection of fHistNN = NULL");
1203     return gHistNN;
1204   }
1205   TH2D *gHistPP = dynamic_cast<TH2D *>(fHistPP->Project(0,1,2));
1206   if(!gHistPP){
1207     AliError("Projection of fHistPP = NULL");
1208     return gHistPP;
1209   }
1210   TH2D *gHistNP = dynamic_cast<TH2D *>(fHistNP->Project(0,1,2));
1211   if(!gHistNP){
1212     AliError("Projection of fHistNP = NULL");
1213     return gHistNP;
1214   }
1215   TH2D *gHistPN = dynamic_cast<TH2D *>(fHistPN->Project(0,1,2));
1216   if(!gHistPN){
1217     AliError("Projection of fHistPN = NULL");
1218     return gHistPN;
1219   }
1220
1221   // sum all 2 particle histograms
1222   gHistNN->Add(gHistPP);
1223   gHistNN->Add(gHistNP);
1224   gHistNN->Add(gHistPN);
1225
1226   // divide by sum of + and - triggers
1227   if((Double_t)(fHistN->Project(0,1)->GetEntries())!=0 && (Double_t)(fHistP->Project(0,1)->GetEntries())!=0)
1228     gHistNN->Scale(1./(Double_t)(fHistN->Project(0,1)->GetEntries() + fHistN->Project(0,1)->GetEntries()));
1229
1230   //normalize to bin width
1231   gHistNN->Scale(1./((Double_t)gHistNN->GetXaxis()->GetBinWidth(1)*(Double_t)gHistNN->GetYaxis()->GetBinWidth(1)));
1232
1233   return gHistNN;
1234 }
1235
1236 //____________________________________________________________________//
1237 Float_t AliBalancePsi::GetDPhiStar(Float_t phi1, Float_t pt1, Float_t charge1, Float_t phi2, Float_t pt2, Float_t charge2, Float_t radius, Float_t bSign) {
1238   //
1239   // calculates dphistar
1240   //
1241   Float_t dphistar = phi1 - phi2 - charge1 * bSign * TMath::ASin(0.075 * radius / pt1) + charge2 * bSign * TMath::ASin(0.075 * radius / pt2);
1242
1243   static const Double_t kPi = TMath::Pi();
1244
1245   // circularity
1246 //   if (dphistar > 2 * kPi)
1247 //     dphistar -= 2 * kPi;
1248 //   if (dphistar < -2 * kPi)
1249 //     dphistar += 2 * kPi;
1250
1251   if (dphistar > kPi)
1252     dphistar = kPi * 2 - dphistar;
1253   if (dphistar < -kPi)
1254     dphistar = -kPi * 2 - dphistar;
1255   if (dphistar > kPi) // might look funny but is needed
1256     dphistar = kPi * 2 - dphistar;
1257
1258   return dphistar;
1259 }
1260