PWG4/omega3pi/AliAnalysisTaskOmegaPi0PiPi.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: Boris Polishchuk (Boris.Polishchuk@cern.ch)                    *
   5  *                                                                        *
   6  * Permission to use, copy, modify and distribute this software and its   *
   7  * documentation strictly for non-commercial purposes is hereby granted   *
   8  * without fee, provided that the above copyright notice appears in all   *
   9  * copies and that both the copyright notice and this permission notice   *
  10  * appear in the supporting documentation. The authors make no claims     *
  11  * about the suitability of this software for any purpose. It is          *
  12  * provided "as is" without express or implied warranty.                  *
  13  **************************************************************************/
  14
  15 ////////////////////////////////////////////////////////////////////////////
  16 //------------------------------------------------------------------------//
  17 // Class used to do omega(782) -> pi0 pi+ pi- analysis.                   //
  18 //------------------------------------------------------------------------//
  19 ////////////////////////////////////////////////////////////////////////////
  20
  21 #include "AliAnalysisTaskOmegaPi0PiPi.h"
  22 #include "TList.h"
  23 #include "TH1.h"
  24 #include "TH2.h"
  25 #include "AliESDEvent.h"
  26 #include "TRefArray.h"
  27 #include "TLorentzVector.h"
  28 #include "AliESDCaloCluster.h"
  29 #include "AliESDv0.h"
  30 #include "AliESDtrack.h"
  31 #include "AliLog.h"
  32
  33 ClassImp(AliAnalysisTaskOmegaPi0PiPi)
  34
  35 AliAnalysisTaskOmegaPi0PiPi::AliAnalysisTaskOmegaPi0PiPi() :
  36   AliAnalysisTaskSE(),fOutputContainer(0x0),fhM2piSel(0x0),fhDxy(0x0),fhMggSel(0x0),
  37   fhImpXY(0x0),fhM3pi0to2(0x0),fhM3pi2to4(0x0),fhM3pi4to6(0x0),fhM3pi6to8(0x0),
  38   fhM3pi8to10(0x0),fhM3pi10to12(0x0),fhM3pi12(0x0),fhM3pi0to8(0x0)
  39 {
  40   //Default constructor.
  41 }
  42
  43
  44 AliAnalysisTaskOmegaPi0PiPi::AliAnalysisTaskOmegaPi0PiPi(const char* name) :
  45   AliAnalysisTaskSE(name),fOutputContainer(0x0),fhM2piSel(0x0),fhDxy(0x0),fhMggSel(0x0),
  46   fhImpXY(0x0),fhM3pi0to2(0x0),fhM3pi2to4(0x0),fhM3pi4to6(0x0),fhM3pi6to8(0x0),
  47   fhM3pi8to10(0x0),fhM3pi10to12(0x0),fhM3pi12(0x0),fhM3pi0to8(0x0)
  48 {
  49   //Constructor used to create a named task.
  50
  51   DefineOutput(1,TList::Class());
  52 }
  53
  54
  55 AliAnalysisTaskOmegaPi0PiPi::~AliAnalysisTaskOmegaPi0PiPi()
  56 {
  57   //Destructor
  58
  59   if(fOutputContainer){
  60     fOutputContainer->Delete() ;
  61     delete fOutputContainer ;
  62   }
  63 }
  64
  65
  66 void AliAnalysisTaskOmegaPi0PiPi::UserCreateOutputObjects()
  67 {
  68   //Allocates histograms and puts it to the output container.
  69
  70   fOutputContainer = new TList();
  71
  72   fhM2piSel = new TH1F("hM2pi_sel","V0 inv. mass, Dxy<2cm",100,0.,1.);
  73   fOutputContainer->Add(fhM2piSel);
  74
  75   fhDxy = new TH1F("hDxy","Distance from V0 to primary vertex in XY-plane", 500, 0.,500.);
  76   fOutputContainer->Add(fhDxy);
  77
  78   fhMggSel = new TH1F("hMgg_sel","Inv. mass of two clusters, pT>1GeV",100,0.,0.3);
  79   fOutputContainer->Add(fhMggSel);
  80
  81   fhImpXY = new TH1F("hImpXY","Impact parameters in XY-plane",1000,0.,1.);
  82   fOutputContainer->Add(fhImpXY);
  83
  84
  85   //M(3pi) vs pT(3pi), ptrack < 2GeV
  86   fhM3pi0to2 = new TH2F("hM3pi_0_2","pTrack: 0-2GeV",100,0.,10., 200,0.4,1.);
  87   fOutputContainer->Add(fhM3pi0to2);
  88
  89   //M(3pi) vs pT(3pi), 2GeV < ptrack < 4GeV
  90   fhM3pi2to4 = new TH2F("hM3pi_2_4","pTrack: 2-4GeV",100,0.,10., 200,0.4,1.);
  91   fOutputContainer->Add(fhM3pi2to4);
  92
  93   //M(3pi) vs pT(3pi), 4GeV < ptrack < 6GeV
  94   fhM3pi4to6 = new TH2F("hM3pi_4_6","pTrack: 4-6GeV",100,0.,10., 200,0.4,1.);
  95   fOutputContainer->Add(fhM3pi4to6);
  96
  97   //M(3pi) vs pT(3pi), 6GeV < ptrack < 8GeV
  98   fhM3pi6to8 = new TH2F("hM3pi_6_8","pTrack: 6-8GeV",100,0.,10., 200,0.4,1.);
  99   fOutputContainer->Add(fhM3pi6to8);
 100
 101   //M(3pi) vs pT(3pi), 8GeV < ptrack < 10GeV
 102   fhM3pi8to10 = new TH2F("hM3pi_8_10","pTrack: 8-10GeV",100,0.,10., 200,0.4,1.);
 103   fOutputContainer->Add(fhM3pi8to10);
 104
 105   //M(3pi) vs pT(3pi), 10GeV < ptrack < 12GeV
 106   fhM3pi10to12 = new TH2F("hM3pi_10_12","pTrack: 10-12GeV",100,0.,10., 200,0.4,1.);
 107   fOutputContainer->Add(fhM3pi10to12);
 108
 109   //M(3pi) vs pT(3pi), ptrack > 12GeV
 110   fhM3pi12 = new TH2F("hM3pi_12","pTrack>12GeV",100,0.,10., 200,0.4,1.);
 111   fOutputContainer->Add(fhM3pi12);
 112
 113   //M(3pi) vs pT(3pi), ptrack < 8GeV
 114   fhM3pi0to8 = new TH2F("hM3pi_0_8","pTrack: 0-8GeV",100,0.,10., 200,0.4,1.);
 115   fOutputContainer->Add(fhM3pi0to8);
 116
 117 }
 118
 119
 120 void AliAnalysisTaskOmegaPi0PiPi::UserExec(Option_t* /* option */)
 121 {
 122   //Main function that does all the job.
 123
 124   AliVEvent* event = InputEvent();
 125   AliESDEvent* esd = (AliESDEvent*)event ;
 126
 127   Double_t v[3] ; //vertex ;
 128   esd->GetVertex()->GetXYZ(v) ;
 129   TVector3 vtx(v);
 130
 131   AliDebug(2,Form("Vertex: (%.3f,%.3f,%.3f)\n",vtx.X(),vtx.Y(),vtx.Z()));
 132
 133   TRefArray * caloClustersArr  = new TRefArray();
 134   esd->GetPHOSClusters(caloClustersArr);
 135
 136   const Int_t kNumberOfTracks = esd->GetNumberOfTracks();
 137   const Int_t kNumberOfV0s = esd->GetNumberOfV0s();
 138
 139   AliDebug(2,Form("Tracks: %d. V0s: %d\n",kNumberOfTracks,kNumberOfV0s));
 140
 141   Float_t xyImp,zImp,imp1,imp2;
 142
 143   const Int_t kNumberOfPhosClusters   = caloClustersArr->GetEntries() ;
 144   AliDebug(2,Form("CaloClusters: %d\n", kNumberOfPhosClusters));
 145   if(kNumberOfPhosClusters<2) return;
 146
 147   TLorentzVector pc1; //4-momentum of PHOS cluster 1
 148   TLorentzVector pc2; //4-momentum of PHOS cluster 2
 149   TLorentzVector pc12;
 150
 151   TLorentzVector ppos; //4-momentum of positive track
 152   TLorentzVector pneg; //4-momentum of negative track
 153   TLorentzVector ptr12;
 154
 155   TLorentzVector pomega;
 156   Double_t etrack;
 157   Double_t p1,p2; // 3-momentum of tracks
 158
 159   const Double_t kMpi = 0.1396;
 160
 161   for(Int_t iClu=0; iClu<kNumberOfPhosClusters; iClu++) {
 162     AliESDCaloCluster *c1 = (AliESDCaloCluster *) caloClustersArr->At(iClu);
 163     c1->GetMomentum(pc1,v);
 164
 165     for (Int_t jClu=iClu; jClu<kNumberOfPhosClusters; jClu++) {
 166       AliESDCaloCluster *c2 = (AliESDCaloCluster *) caloClustersArr->At(jClu);
 167       if(c2->IsEqual(c1)) continue;
 168       c2->GetMomentum(pc2,v);
 169
 170       pc12 = pc1+pc2;
 171       AliDebug(2,Form("pc12.M(): %.3f\n",pc12.M()));
 172
 173       if(pc12.M()<0.115 || pc12.M()>0.155) continue; //not a pi0 candidate!
 174       if(pc12.Pt()<1.) continue; //pT(pi0) > 1GeV
 175
 176       fhMggSel->Fill(pc12.M());
 177
 178       for(Int_t iTrack=0; iTrack<kNumberOfTracks; iTrack++) {
 179         AliESDtrack* tr1 = esd->GetTrack(iTrack);
 180         p1 = tr1->P();
 181         tr1->GetImpactParameters(xyImp,zImp);
 182         imp1 = TMath::Abs(xyImp);
 183         fhImpXY->Fill(imp1);
 184         Short_t charge = tr1->Charge();
 185         if(imp1>0.004) continue; // not from the primary vertex!
 186
 187         etrack = TMath::Sqrt(p1*p1 + kMpi*kMpi);
 188         ppos.SetPxPyPzE(tr1->Px(),tr1->Py(),tr1->Pz(),etrack);
 189
 190         for(Int_t jTrack=iTrack; jTrack<kNumberOfTracks; jTrack++) {
 191           AliESDtrack* tr2 = esd->GetTrack(jTrack);
 192           p2 = tr2->P();
 193           if(tr2->Charge()==charge) continue; //same sign track (WRONG!!)
 194           tr2->GetImpactParameters(xyImp,zImp);
 195           imp2=TMath::Abs(xyImp);
 196           if(imp2>0.004) continue; // not from the primary vertex!
 197
 198           etrack = TMath::Sqrt(p2*p2 + kMpi*kMpi);
 199           pneg.SetPxPyPzE(tr2->Px(),tr2->Py(),tr2->Pz(),etrack);
 200
 201           ptr12 = ppos + pneg;
 202
 203 //        printf("ptr12.M()=%.3f, xyImp1=%f, xyImp2=%f, ch1=%d, ch2=%d,
 204 //                  p1=%.3f, p2=%.3f, m1=%.3f, m2=%.3f\n",
 205 //               ptr12.M(),imp1,imp2,tr1->Charge(),tr2->Charge(),
 206 //               tr1->P(),tr2->P(),tr1->M(),tr2->M());
 207
 208           pomega = pc12 + ptr12;
 209           AliDebug(2,Form("pomega.M(): %f\n",pomega.M()));
 210
 211           if( p1<2. && p2<2. )
 212             fhM3pi0to2->Fill(pomega.Pt(),pomega.M());
 213
 214           if( (p1>=2. && p1<4.) && (p2>=2. && p2<4.) )
 215             fhM3pi2to4->Fill(pomega.Pt(),pomega.M());
 216
 217           if( (p1>=4. && p1<6.) && (p2>=4. && p2<6.) )
 218             fhM3pi4to6->Fill(pomega.Pt(),pomega.M());
 219
 220           if( (p1>=6. && p1<8.) && (p2>=6. && p2<8.) )
 221             fhM3pi6to8->Fill(pomega.Pt(),pomega.M());
 222
 223           if( (p1>=8. && p1<10.) && (p2>=8. && p2<10.) )
 224             fhM3pi8to10->Fill(pomega.Pt(),pomega.M());
 225
 226           if( (p1>=10. && p1<12.) && (p2>=10. && p2<12.) )
 227             fhM3pi10to12->Fill(pomega.Pt(),pomega.M());
 228
 229           if( (p1>=12.) && (p2>=12.) )
 230             fhM3pi12->Fill(pomega.Pt(),pomega.M());
 231
 232           if( p1<8. && p2<8. )
 233             fhM3pi0to8->Fill(pomega.Pt(),pomega.M());
 234
 235         }
 236       }
 237
 238       for(Int_t iVert=0; iVert<kNumberOfV0s; iVert++) {
 239         AliESDv0* v0 = esd->GetV0(iVert);
 240         AliESDtrack* ptrack = esd->GetTrack(v0->GetPindex()); //positive track
 241         AliESDtrack* ntrack = esd->GetTrack(v0->GetNindex()); //negative track
 242
 243         etrack = TMath::Sqrt(ptrack->P()*ptrack->P() + kMpi*kMpi);
 244         ppos.SetPxPyPzE(ptrack->Px(),ptrack->Py(),ptrack->Pz(),etrack);
 245
 246         etrack = TMath::Sqrt(ntrack->P()*ntrack->P() + kMpi*kMpi);
 247         pneg.SetPxPyPzE(ntrack->Px(),ntrack->Py(),ntrack->Pz(),etrack);
 248
 249         ptr12 = ppos + pneg;
 250
 251         Double_t dx = vtx.X() - v0->Xv();
 252         Double_t dy = vtx.Y() - v0->Yv();
 253         Double_t dxy = TMath::Sqrt(dx*dx + dy*dy);
 254         fhDxy->Fill(dxy);
 255
 256         AliDebug(2,Form("V0: dxy=%.3f\n",dxy));
 257
 258         if(dxy<2.) fhM2piSel->Fill(ptr12.M());
 259       }
 260
 261     }
 262   }
 263
 264   delete caloClustersArr;
 265   PostData(1,fOutputContainer);
 266 }