Coding conventions, additional comments, code clean-up (Yu.Belikov)
[u/mrichter/AliRoot.git] / ITS / AliV0vertexer.cxx
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7f6ddf58 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// Implementation of the V0 vertexer class
18856a77 18// reads tracks writes out V0 vertices
19// fills the ESD with the V0s
7f6ddf58 20// Origin: Iouri Belikov, IReS, Strasbourg, Jouri.Belikov@cern.ch
21//-------------------------------------------------------------------------
7f6ddf58 22#include <TObjArray.h>
116cbefd 23#include <TTree.h>
7f6ddf58 24
e23730c7 25#include "AliESD.h"
26#include "AliESDtrack.h"
116cbefd 27#include "AliITStrackV2.h"
7f6ddf58 28#include "AliV0vertex.h"
29#include "AliV0vertexer.h"
7f6ddf58 30
31ClassImp(AliV0vertexer)
32
e23730c7 33Int_t AliV0vertexer::Tracks2V0vertices(AliESD *event) {
34 //--------------------------------------------------------------------
35 //This function reconstructs V0 vertices
36 //--------------------------------------------------------------------
37
38 Int_t nentr=event->GetNumberOfTracks();
39
40 TObjArray negtrks(nentr/2);
41 TObjArray postrks(nentr/2);
42
43 Int_t nneg=0, npos=0, nvtx=0;
44
45 Int_t i;
46 for (i=0; i<nentr; i++) {
47 AliESDtrack *esd=event->GetTrack(i);
48 Int_t status=esd->GetStatus();
49
50 if ((status&AliESDtrack::kITSrefit)==0)
51 if ((status&AliESDtrack::kITSout)!=0 || (status&AliESDtrack::kITSin)==0)
52 continue;
53
54 AliITStrackV2 *iotrack=new AliITStrackV2(*esd);
55 iotrack->SetLabel(i); // now it is the index in array of ESD tracks
18856a77 56 if ((status&AliESDtrack::kITSrefit)==0) //correction for the beam pipe
57 iotrack->PropagateTo(3.,0.0023,65.19); //material
e23730c7 58 iotrack->PropagateTo(2.5,0.,0.);
59
60 if (iotrack->Get1Pt() > 0.) {nneg++; negtrks.AddLast(iotrack);}
61 else {npos++; postrks.AddLast(iotrack);}
62 }
63
64
65 for (i=0; i<nneg; i++) {
66 //if (i%10==0) cerr<<nneg-i<<'\r';
67 AliITStrackV2 *ntrk=(AliITStrackV2 *)negtrks.UncheckedAt(i);
68
69 if (TMath::Abs(ntrk->GetD(fX,fY))<fDPmin) continue;
70 if (TMath::Abs(ntrk->GetD(fX,fY))>fRmax) continue;
71
72 for (Int_t k=0; k<npos; k++) {
73 AliITStrackV2 *ptrk=(AliITStrackV2 *)postrks.UncheckedAt(k);
74
75 if (TMath::Abs(ptrk->GetD(fX,fY))<fDPmin) continue;
76 if (TMath::Abs(ptrk->GetD(fX,fY))>fRmax) continue;
77
78 if (TMath::Abs(ntrk->GetD(fX,fY))<fDNmin)
79 if (TMath::Abs(ptrk->GetD(fX,fY))<fDNmin) continue;
80
81
82 AliITStrackV2 nt(*ntrk), pt(*ptrk), *pnt=&nt, *ppt=&pt;
83
84 Double_t dca=PropagateToDCA(pnt,ppt);
85 if (dca > fDCAmax) continue;
86
87 AliV0vertex vertex(*pnt,*ppt);
88 if (vertex.GetChi2() > fChi2max) continue;
89
90 /* Think of something better here !
91 nt.PropagateToVertex(); if (TMath::Abs(nt.GetZ())<0.04) continue;
92 pt.PropagateToVertex(); if (TMath::Abs(pt.GetZ())<0.04) continue;
93 */
94
95 Double_t x,y,z; vertex.GetXYZ(x,y,z);
96 Double_t r2=x*x + y*y;
97 if (r2 > fRmax*fRmax) continue;
98 if (r2 < fRmin*fRmin) continue;
99
100 Double_t px,py,pz; vertex.GetPxPyPz(px,py,pz);
101 Double_t p2=px*px+py*py+pz*pz;
102 Double_t cost=((x-fX)*px + (y-fY)*py + (z-fZ)*pz)/
103 TMath::Sqrt(p2*((x-fX)*(x-fX) + (y-fY)*(y-fY) + (z-fZ)*(z-fZ)));
104
105 //if (cost < (5*fCPAmax-0.9-TMath::Sqrt(r2)*(fCPAmax-1))/4.1) continue;
106 if (cost < fCPAmax) continue;
107
108 //vertex.ChangeMassHypothesis(); //default is Lambda0
109
110 event->AddV0(&vertex);
111
112 nvtx++;
113 }
114 }
115
116 Info("Tracks2V0vertices","Number of reconstructed V0 vertices: %d",nvtx);
117
118 negtrks.Delete();
119 postrks.Delete();
120
121 return 0;
122}
123
566abf75 124Int_t AliV0vertexer::Tracks2V0vertices(TTree *tTree, TTree *vTree) {
7f6ddf58 125 //--------------------------------------------------------------------
126 //This function reconstructs V0 vertices
127 //--------------------------------------------------------------------
566abf75 128 TBranch *branch=tTree->GetBranch("tracks");
129 if (!branch) {
130 Error("Tracks2V0vertices","Can't get the branch !");
131 return 1;
7f6ddf58 132 }
566abf75 133 Int_t nentr=(Int_t)tTree->GetEntries();
7f6ddf58 134
135 TObjArray negtrks(nentr/2);
136 TObjArray postrks(nentr/2);
137
138 Int_t nneg=0, npos=0, nvtx=0;
139
140 Int_t i;
141 for (i=0; i<nentr; i++) {
142 AliITStrackV2 *iotrack=new AliITStrackV2;
143 branch->SetAddress(&iotrack);
566abf75 144 tTree->GetEvent(i);
4ab260d6 145
146 iotrack->PropagateTo(3.,0.0023,65.19); iotrack->PropagateTo(2.5,0.,0.);
147
7f6ddf58 148 if (iotrack->Get1Pt() > 0.) {nneg++; negtrks.AddLast(iotrack);}
149 else {npos++; postrks.AddLast(iotrack);}
150 }
151
152
7f6ddf58 153 AliV0vertex *ioVertex=0;
566abf75 154 branch=vTree->GetBranch("vertices");
155 if (!branch) vTree->Branch("vertices","AliV0vertex",&ioVertex,32000,3);
156 else branch->SetAddress(&ioVertex);
7f6ddf58 157
158
159 for (i=0; i<nneg; i++) {
e23730c7 160 //if (i%10==0) cerr<<nneg-i<<'\r';
7f6ddf58 161 AliITStrackV2 *ntrk=(AliITStrackV2 *)negtrks.UncheckedAt(i);
a9a2d814 162
5d390eda 163 if (TMath::Abs(ntrk->GetD(fX,fY))<fDPmin) continue;
164 if (TMath::Abs(ntrk->GetD(fX,fY))>fRmax) continue;
4ab260d6 165
7f6ddf58 166 for (Int_t k=0; k<npos; k++) {
167 AliITStrackV2 *ptrk=(AliITStrackV2 *)postrks.UncheckedAt(k);
168
5d390eda 169 if (TMath::Abs(ptrk->GetD(fX,fY))<fDPmin) continue;
170 if (TMath::Abs(ptrk->GetD(fX,fY))>fRmax) continue;
4ab260d6 171
5d390eda 172 if (TMath::Abs(ntrk->GetD(fX,fY))<fDNmin)
173 if (TMath::Abs(ptrk->GetD(fX,fY))<fDNmin) continue;
4ab260d6 174
7f6ddf58 175
176 AliITStrackV2 nt(*ntrk), pt(*ptrk), *pnt=&nt, *ppt=&pt;
177
178 Double_t dca=PropagateToDCA(pnt,ppt);
179 if (dca > fDCAmax) continue;
180
181 AliV0vertex vertex(*pnt,*ppt);
182 if (vertex.GetChi2() > fChi2max) continue;
183
184 /* Think of something better here !
185 nt.PropagateToVertex(); if (TMath::Abs(nt.GetZ())<0.04) continue;
186 pt.PropagateToVertex(); if (TMath::Abs(pt.GetZ())<0.04) continue;
187 */
188
189 Double_t x,y,z; vertex.GetXYZ(x,y,z);
190 Double_t r2=x*x + y*y;
191 if (r2 > fRmax*fRmax) continue;
192 if (r2 < fRmin*fRmin) continue;
193
194 Double_t px,py,pz; vertex.GetPxPyPz(px,py,pz);
195 Double_t p2=px*px+py*py+pz*pz;
5d390eda 196 Double_t cost=((x-fX)*px + (y-fY)*py + (z-fZ)*pz)/
e23730c7 197 TMath::Sqrt(p2*((x-fX)*(x-fX) + (y-fY)*(y-fY) + (z-fZ)*(z-fZ)));
4ab260d6 198
e23730c7 199 //if (cost < (5*fCPAmax-0.9-TMath::Sqrt(r2)*(fCPAmax-1))/4.1) continue;
5d390eda 200 if (cost < fCPAmax) continue;
7f6ddf58 201
202 //vertex.ChangeMassHypothesis(); //default is Lambda0
203
566abf75 204 ioVertex=&vertex; vTree->Fill();
7f6ddf58 205
206 nvtx++;
207 }
208 }
209
e23730c7 210 Info("Tracks2V0vertices","Number of reconstructed V0 vertices: %d",nvtx);
7f6ddf58 211
7f6ddf58 212 negtrks.Delete();
213 postrks.Delete();
214
7f6ddf58 215 return 0;
216}
217
18856a77 218Double_t
219AliV0vertexer::PropagateToDCA(AliITStrackV2 *n, AliITStrackV2 *p) const {
7f6ddf58 220 //--------------------------------------------------------------------
221 // This function returns the DCA between two tracks
222 // The tracks will be moved to the point of DCA !
223 //--------------------------------------------------------------------
49a7a79a 224 return n->PropagateToDCA(p);
7f6ddf58 225}
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