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1 | /************************************************************************** | |
2 | * Copyright(c) 1998-2007, 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 | #include <TClonesArray.h> | |
17 | #include "AliLog.h" | |
18 | #include "AliESDVertex.h" | |
19 | #include "AliRunLoader.h" | |
20 | #include "AliITSLoader.h" | |
21 | #include "AliITSgeomTGeo.h" | |
22 | #include "AliITSRecPoint.h" | |
23 | #include "AliITSVertexerCosmics.h" | |
24 | #include "AliStrLine.h" | |
25 | ||
26 | //------------------------------------------------------------------------ | |
27 | // This class implements a method to construct a "fake" primary | |
28 | // vertex for cosmic events in which the muon crosses one of 5 inner | |
29 | // ITS layers. A fake primary vertex is needed for the reconstruction, | |
30 | // with e.g. AliITStrackerSA, of the two tracks produced by the muon | |
31 | // in the ITS. | |
32 | // We build pairs of clusters on a given layer and define the fake vertex as | |
33 | // the mid-point of the straight line joining the two clusters. | |
34 | // We use the innermost layer that has at least two clusters. | |
35 | // We reject the background by requiring at least one cluster on the outer | |
36 | // layer, closer than fMaxDistOnOuterLayer to the tracklet prolongation. | |
37 | // We can reject (potentially pathological) events with the muon track | |
38 | // tangential to the layer by the requiring the radial position of | |
39 | // the vertex to be smaller than fMaxVtxRadius. | |
40 | // Due to background clusters, more than one vertex per event can | |
41 | // be found. We consider the first found. | |
42 | // The errors on x,y,z of the vertex are calculated as errors on the mean | |
43 | // of clusters coordinates. Non-diag elements of vertex cov. mat. are set to 0. | |
44 | // The number of contributors set in the AliESDVertex object is the | |
45 | // number of the layer on which the tracklet was built; if this number is -1, | |
46 | // the procedure could not find a vertex position and by default | |
47 | // the vertex coordinates are set to (0,0,0) with large errors (100,100,100) | |
48 | // | |
49 | // Origin: A.Dainese, andrea.dainese@lnl.infn.it | |
50 | //------------------------------------------------------------------------- | |
51 | ||
52 | ClassImp(AliITSVertexerCosmics) | |
53 | ||
54 | //------------------------------------------------------------------------- | |
55 | AliITSVertexerCosmics::AliITSVertexerCosmics():AliITSVertexer(), | |
56 | fMaxDistOnOuterLayer(0), | |
57 | fMinDist2Vtxs(0) | |
58 | { | |
59 | // Default constructor | |
60 | SetFirstLastModules(0,0,79); | |
61 | SetFirstLastModules(1,80,239); | |
62 | SetFirstLastModules(2,240,323); | |
63 | SetFirstLastModules(3,324,499); | |
64 | SetFirstLastModules(4,500,1247); | |
65 | SetFirstLastModules(5,1248,2197); | |
66 | SetMaxVtxRadius(0,3.5); | |
67 | SetMaxVtxRadius(1,6.5); | |
68 | SetMaxVtxRadius(2,14.5); | |
69 | SetMaxVtxRadius(3,23.5); | |
70 | SetMaxVtxRadius(4,37.5); | |
71 | SetMaxVtxRadius(5,42.5); | |
72 | SetMaxDistOnOuterLayer(); | |
73 | SetMinDist2Vtxs(); | |
74 | } | |
75 | //-------------------------------------------------------------------------- | |
76 | AliESDVertex* AliITSVertexerCosmics::FindVertexForCurrentEvent(Int_t evnumber) | |
77 | { | |
78 | // Defines the AliESDVertex for the current event | |
79 | ||
80 | fCurrentVertex = 0; | |
81 | AliRunLoader *rl =AliRunLoader::GetRunLoader(); | |
82 | AliITSLoader* itsLoader = (AliITSLoader*)rl->GetLoader("ITSLoader"); | |
83 | itsLoader->LoadRecPoints(); | |
84 | rl->GetEvent(evnumber); | |
85 | ||
86 | TTree *rpTree = itsLoader->TreeR(); | |
87 | ||
88 | TClonesArray *recpoints=new TClonesArray("AliITSRecPoint",10000); | |
89 | rpTree->SetBranchAddress("ITSRecPoints",&recpoints); | |
90 | ||
91 | Int_t lay,lad,det; | |
92 | ||
93 | // Search for innermost layer with at least two clusters | |
94 | // on two different modules | |
95 | Int_t ilayer=0; | |
96 | while(ilayer<6) { | |
97 | Int_t nHitModules=0; | |
98 | for(Int_t imodule=fFirst[ilayer]; imodule<=fLast[ilayer]; imodule++) { | |
99 | rpTree->GetEvent(imodule); | |
100 | AliITSgeomTGeo::GetModuleId(imodule,lay,lad,det); | |
101 | lay -= 1; // AliITSgeomTGeo gives layer from 1 to 6, we want 0 to 5 | |
102 | if(lay!=ilayer) AliFatal("Layer mismatch!"); | |
103 | if(recpoints->GetEntriesFast()>0) nHitModules++; | |
104 | } | |
105 | if(nHitModules>=2) break; | |
106 | ilayer++; | |
107 | } | |
108 | printf("Building tracklets on layer %d\n",ilayer); | |
109 | ||
110 | const Int_t arrSize = 1000; | |
111 | Float_t xclInnLay[arrSize],yclInnLay[arrSize],zclInnLay[arrSize],modclInnLay[arrSize]; | |
112 | Float_t e2xclInnLay[arrSize],e2yclInnLay[arrSize],e2zclInnLay[arrSize]; | |
113 | Int_t nclInnLayStored=0; | |
114 | Float_t xclOutLay[arrSize],yclOutLay[arrSize],zclOutLay[arrSize],modclOutLay[arrSize]; | |
115 | Int_t nclOutLayStored=0; | |
116 | Int_t nRecPoints,nRecPointsInnLay=0; | |
117 | ||
118 | Float_t gc[3],gcov[5]; | |
119 | ||
120 | Float_t x[arrSize],y[arrSize],z[arrSize],e2x[arrSize],e2y[arrSize],e2z[arrSize]; | |
121 | Double_t p1[3],p2[3],p3[3]; | |
122 | Int_t nvtxs; | |
123 | Bool_t good,matchtoOutLay; | |
124 | Float_t xvtx,yvtx,zvtx,rvtx; | |
125 | ||
126 | Double_t pos[3]={0.,0.,0.}; | |
127 | Double_t err[3]={100.,100.,100.}; | |
128 | Int_t ncontributors = -1; | |
129 | ||
130 | // Collect clusters in the selected layer and the outer one | |
131 | for(Int_t imodule=fFirst[ilayer]; imodule<=fLast[ilayer+1]; imodule++) { | |
132 | rpTree->GetEvent(imodule); | |
133 | AliITSgeomTGeo::GetModuleId(imodule,lay,lad,det); | |
134 | lay -= 1; // AliITSgeomTGeo gives layer from 1 to 6, we want 0 to 5 | |
135 | nRecPoints=recpoints->GetEntriesFast(); | |
136 | if(imodule<=fLast[ilayer]) nRecPointsInnLay += nRecPoints; | |
137 | //printf("cosmics: module %d clusters %d\n",imodule,nRecPoints); | |
138 | for(Int_t irp=0; irp<nRecPoints; irp++) { | |
139 | AliITSRecPoint *rp=(AliITSRecPoint*)recpoints->UncheckedAt(irp); | |
140 | // Local coordinates of this recpoint | |
141 | rp->GetGlobalXYZ(gc); | |
142 | if(lay==ilayer) { // store InnLay clusters | |
143 | xclInnLay[nclInnLayStored]=gc[0]; | |
144 | yclInnLay[nclInnLayStored]=gc[1]; | |
145 | zclInnLay[nclInnLayStored]=gc[2]; | |
146 | rp->GetGlobalCov(gcov); | |
147 | e2xclInnLay[nclInnLayStored]=gcov[0]; | |
148 | e2yclInnLay[nclInnLayStored]=gcov[3]; | |
149 | e2zclInnLay[nclInnLayStored]=gcov[5]; | |
150 | modclInnLay[nclInnLayStored]=imodule; | |
151 | nclInnLayStored++; | |
152 | } | |
153 | if(lay==ilayer+1) { // store OutLay clusters | |
154 | xclOutLay[nclOutLayStored]=gc[0]; | |
155 | yclOutLay[nclOutLayStored]=gc[1]; | |
156 | zclOutLay[nclOutLayStored]=gc[2]; | |
157 | modclOutLay[nclOutLayStored]=imodule; | |
158 | nclOutLayStored++; | |
159 | } | |
160 | if(nclInnLayStored>arrSize || nclOutLayStored>arrSize) { | |
161 | //AliFatal("More than arrSize clusters per layer"); | |
162 | AliWarning("Too many clusters per layer"); | |
163 | delete recpoints; | |
164 | itsLoader->UnloadRecPoints(); | |
165 | fCurrentVertex = new AliESDVertex(pos,err,"cosmics"); | |
166 | fCurrentVertex->SetTitle("cosmics fake vertex (failed)"); | |
167 | fCurrentVertex->SetNContributors(ncontributors); | |
168 | return fCurrentVertex; | |
169 | } | |
170 | }// end clusters in a module | |
171 | }// end modules | |
172 | ||
173 | // build fake vertices | |
174 | nvtxs=0; | |
175 | // InnLay - first cluster | |
176 | for(Int_t i1InnLay=0; i1InnLay<nclInnLayStored; i1InnLay++) { | |
177 | p1[0]=xclInnLay[i1InnLay]; | |
178 | p1[1]=yclInnLay[i1InnLay]; | |
179 | p1[2]=zclInnLay[i1InnLay]; | |
180 | // InnLay - second cluster | |
181 | for(Int_t i2InnLay=i1InnLay+1; i2InnLay<nclInnLayStored; i2InnLay++) { | |
182 | if(modclInnLay[i1InnLay]==modclInnLay[i2InnLay]) continue; | |
183 | p2[0]=xclInnLay[i2InnLay]; | |
184 | p2[1]=yclInnLay[i2InnLay]; | |
185 | p2[2]=zclInnLay[i2InnLay]; | |
186 | // look for point on OutLay | |
187 | AliStrLine InnLayline(p1,p2,kTRUE); | |
188 | matchtoOutLay = kFALSE; | |
189 | for(Int_t iOutLay=0; iOutLay<nclOutLayStored; iOutLay++) { | |
190 | p3[0]=xclOutLay[iOutLay]; | |
191 | p3[1]=yclOutLay[iOutLay]; | |
192 | p3[2]=zclOutLay[iOutLay]; | |
193 | //printf(" %f\n",InnLayline.GetDistFromPoint(p3)); | |
194 | if(InnLayline.GetDistFromPoint(p3)<fMaxDistOnOuterLayer) | |
195 | { matchtoOutLay = kTRUE; break; } | |
196 | } | |
197 | if(!matchtoOutLay) continue; | |
198 | xvtx = 0.5*(xclInnLay[i1InnLay]+xclInnLay[i2InnLay]); | |
199 | yvtx = 0.5*(yclInnLay[i1InnLay]+yclInnLay[i2InnLay]); | |
200 | zvtx = 0.5*(zclInnLay[i1InnLay]+zclInnLay[i2InnLay]); | |
201 | rvtx = TMath::Sqrt(xvtx*xvtx+yvtx*yvtx); | |
202 | if(rvtx>fMaxVtxRadius[ilayer]) continue; | |
203 | good = kTRUE; | |
204 | for(Int_t iv=0; iv<nvtxs; iv++) { | |
205 | if(TMath::Sqrt((xvtx- x[iv])*(xvtx- x[iv])+ | |
206 | (yvtx- y[iv])*(yvtx- y[iv])+ | |
207 | (zvtx- z[iv])*(zvtx- z[iv])) < fMinDist2Vtxs) | |
208 | good = kFALSE; | |
209 | } | |
210 | if(good) { | |
211 | x[nvtxs]=xvtx; | |
212 | y[nvtxs]=yvtx; | |
213 | z[nvtxs]=zvtx; | |
214 | e2x[nvtxs]=0.25*(e2xclInnLay[i1InnLay]+e2xclInnLay[i2InnLay]); | |
215 | e2y[nvtxs]=0.25*(e2yclInnLay[i1InnLay]+e2yclInnLay[i2InnLay]); | |
216 | e2z[nvtxs]=0.25*(e2zclInnLay[i1InnLay]+e2zclInnLay[i2InnLay]); | |
217 | nvtxs++; | |
218 | } | |
219 | } // InnLay - second cluster | |
220 | } // InnLay - first cluster | |
221 | ||
222 | if(nvtxs) { | |
223 | ncontributors = ilayer; | |
224 | pos[0]=x[0]; | |
225 | pos[1]=y[0]; | |
226 | pos[2]=z[0]; | |
227 | err[0]=TMath::Sqrt(e2x[0]); | |
228 | err[1]=TMath::Sqrt(e2y[0]); | |
229 | err[2]=TMath::Sqrt(e2z[0]); | |
230 | } | |
231 | ||
232 | fCurrentVertex = new AliESDVertex(pos,err,"cosmics"); | |
233 | fCurrentVertex->SetTitle("cosmics fake vertex"); | |
234 | fCurrentVertex->SetNContributors(ncontributors); | |
235 | //fCurrentVertex->Print(); | |
236 | ||
237 | delete recpoints; | |
238 | itsLoader->UnloadRecPoints(); | |
239 | ||
240 | return fCurrentVertex; | |
241 | } | |
242 | //------------------------------------------------------------------------- | |
243 | void AliITSVertexerCosmics::FindVertices() | |
244 | { | |
245 | // computes the vertices of the events in the range FirstEvent - LastEvent | |
246 | AliRunLoader *rl = AliRunLoader::GetRunLoader(); | |
247 | AliITSLoader* itsLoader = (AliITSLoader*) rl->GetLoader("ITSLoader"); | |
248 | itsLoader->ReloadRecPoints(); | |
249 | for(Int_t i=fFirstEvent;i<=fLastEvent;i++){ | |
250 | // printf("Processing event %d\n",i); | |
251 | rl->GetEvent(i); | |
252 | FindVertexForCurrentEvent(i); | |
253 | if(fCurrentVertex){ | |
254 | WriteCurrentVertex(); | |
255 | } | |
256 | } | |
257 | } | |
258 | //------------------------------------------------------------------------- | |
259 | void AliITSVertexerCosmics::PrintStatus() const | |
260 | { | |
261 | // Print current status | |
262 | printf("=======================================================\n"); | |
263 | printf(" fMaxDistOnOuterLayer: %f\n",fMaxDistOnOuterLayer); | |
264 | printf(" fMaxVtxRadius[0]: %f\n",fMaxVtxRadius[0]); | |
265 | printf(" fMinDist2Vtxs: %f\n",fMinDist2Vtxs); | |
266 | printf("=======================================================\n"); | |
267 | } | |
268 | //------------------------------------------------------------------------- |