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99e5fe42 | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
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 | **************************************************************************/ | |
15 | ||
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 | //--------------------------------------------------------------------- | |
21 | ||
22 | #include <Riostream.h> | |
23 | #include <TMath.h> | |
24 | #include <TClonesArray.h> | |
25 | #include <TLorentzVector.h> | |
26 | ||
27 | #include "AliLeading.h" | |
28 | #include <AliJetReader.h> | |
29 | ||
30 | ClassImp(AliLeading) | |
31 | ||
32 | //////////////////////////////////////////////////////////////////////// | |
33 | ||
34 | AliLeading::AliLeading() | |
35 | { | |
36 | // | |
37 | // Constructor | |
38 | // | |
39 | fNassoc=0; | |
40 | fLeading = new TLorentzVector(0.,0.,0.,0.); | |
41 | fLow = -TMath::Pi()/2.0; | |
42 | fnBin=45; | |
43 | fCorr = TArrayI(fnBin); | |
44 | } | |
45 | ||
46 | //////////////////////////////////////////////////////////////////////// | |
47 | ||
48 | AliLeading::~AliLeading() | |
49 | { | |
50 | // | |
51 | // Destructor | |
52 | // | |
53 | delete fLeading; | |
54 | } | |
55 | ||
56 | //////////////////////////////////////////////////////////////////////// | |
57 | ||
58 | void AliLeading::FindLeading(AliJetReader *reader) | |
59 | ||
60 | { | |
61 | // | |
62 | // find leading particle in the array of lorentz vectors | |
63 | // lvArray and fill the correlation histogram | |
64 | // | |
65 | TClonesArray* lvArray = reader->GetMomentumArray(); | |
66 | Int_t nIn = lvArray->GetEntries(); | |
67 | fNassoc = nIn-1; | |
68 | ||
69 | if (fNassoc < 0) return; | |
70 | ||
71 | // find max | |
72 | Double_t ptMax = 0.0; | |
73 | Int_t idxMax = -1; | |
74 | for (Int_t i=0; i<nIn;i++){ | |
75 | TLorentzVector *lv = (TLorentzVector*) lvArray->At(i); | |
76 | if (lv->Pt() > ptMax) { | |
77 | ptMax = lv->Pt(); | |
78 | idxMax = i; | |
79 | } | |
80 | } | |
81 | ||
82 | // fill correlation array | |
83 | fLeading = (TLorentzVector*) lvArray->At(idxMax); | |
84 | for (Int_t i=0; i<nIn;i++){ | |
85 | if (i == idxMax) continue; | |
86 | TLorentzVector *lv = (TLorentzVector*) lvArray->At(i); | |
87 | Double_t dphi = fLeading->DeltaPhi(*lv); | |
88 | if (dphi < fLow) dphi=2.0*TMath::Pi()+dphi; | |
89 | // find bin and fill array | |
90 | ||
91 | Int_t iBin = (Int_t) TMath::Floor((dphi-fLow) | |
92 | *((Double_t)fnBin)/(2.0*TMath::Pi())); | |
93 | fCorr.AddAt(fCorr.At(iBin)+1,iBin); | |
94 | } | |
95 | } | |
96 | ||
97 | //////////////////////////////////////////////////////////////////////// | |
98 | ||
99 | void AliLeading::Reset() | |
100 | ||
101 | { | |
102 | // Reset leding particle information | |
103 | fLeading->SetPxPyPzE(0.,0.,0.,0.); | |
104 | fNassoc=0; | |
105 | fCorr.Reset(); | |
106 | } | |
107 | ||
108 | //////////////////////////////////////////////////////////////////////// | |
109 | ||
110 | void AliLeading::PrintLeading() | |
111 | ||
112 | { | |
113 | // Print leading particle information | |
114 | if (fNassoc<0) { | |
115 | cout << " No leading particle in this event" << endl; | |
116 | return; | |
117 | } | |
118 | cout << " Leading particle: " << endl; | |
119 | cout << " (px,py,pz,e) = (" << fLeading->Px() << "," | |
120 | << fLeading->Py() << "," << fLeading->Pz() << "," | |
121 | << fLeading->E() << ")" << endl; | |
122 | cout << " (pt,eta,phi) = (" << fLeading->Pt() << "," | |
123 | << fLeading->Eta() << "," << fLeading->Phi() << ")" << endl; | |
124 | cout << " " << fNassoc << " associated particles." << endl; | |
125 | } |