1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
16 //---------------------------------------------------------------------
17 // Class to find and store the leading particle in event and
18 // store its correlation to associated particles
19 // Author: jgcn@mda.cinvestav.mx
20 //---------------------------------------------------------------------
22 #include <Riostream.h>
24 #include <TClonesArray.h>
25 #include <TLorentzVector.h>
27 #include "AliLeading.h"
28 #include "AliJetReader.h"
29 #include "AliJetReaderHeader.h"
33 ////////////////////////////////////////////////////////////////////////
35 AliLeading::AliLeading()
41 fLeading = new TLorentzVector(0.,0.,0.,0.);
42 fLow = -TMath::Pi()/2.0;
44 fCorr = TArrayI(fnBin);
48 ////////////////////////////////////////////////////////////////////////
50 AliLeading::~AliLeading()
58 ////////////////////////////////////////////////////////////////////////
60 void AliLeading::FindLeading(AliJetReader *reader)
64 // find leading particle in the array of lorentz vectors
65 // lvArray and fill the correlation histogram
69 AliJetReaderHeader* header = reader->GetReaderHeader();
71 TClonesArray* lvArray = reader->GetMomentumArray();
72 Int_t nIn = lvArray->GetEntries();
75 if (fNassoc < 0) return;
80 for (Int_t i = 0; i < nIn; i++){
81 TLorentzVector *lv = (TLorentzVector*) lvArray->At(i);
82 if (lv->Pt() > ptMax &&
83 lv->Eta() > header->GetFiducialEtaMin() &&
84 lv->Eta() < header->GetFiducialEtaMax())
97 // fill correlation array
98 fLeading = (TLorentzVector*) lvArray->At(idxMax);
101 for (Int_t i = 0; i < nIn; i++) {
102 if (i == idxMax) continue;
103 TLorentzVector *lv = (TLorentzVector*) lvArray->At(i);
104 Double_t dphi = fLeading->DeltaPhi(*lv);
105 if (dphi < fLow) dphi = 2.0 * TMath::Pi() + dphi;
106 // find bin and fill array
109 TMath::Floor((dphi - fLow)
110 *((Double_t) fnBin) / (2.0 * TMath::Pi()));
111 fCorr.AddAt(fCorr.At(iBin)+1,iBin);
115 ////////////////////////////////////////////////////////////////////////
117 void AliLeading::Reset()
120 // Reset leading particle information
121 fLeading->SetPxPyPzE(0., 0., 0., 0.);
126 ////////////////////////////////////////////////////////////////////////
128 void AliLeading::PrintLeading()
131 // Print leading particle information
133 cout << " No leading particle in this event" << endl;
136 cout << " Leading particle: " << endl;
137 cout << " (px,py,pz,e) = (" << fLeading->Px() << ","
138 << fLeading->Py() << "," << fLeading->Pz() << ","
139 << fLeading->E() << ")" << endl;
140 cout << " (pt,eta,phi) = (" << fLeading->Pt() << ","
141 << fLeading->Eta() << "," << fLeading->Phi() << ")" << endl;
142 cout << " " << fNassoc << " associated particles." << endl;