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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 <TTree.h> | |
18 | #include "AliLog.h" | |
19 | #include "AliESDVertex.h" | |
20 | #include "AliITSgeomTGeo.h" | |
21 | #include "AliITSRecPoint.h" | |
22 | #include "AliITSReconstructor.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 | /* | |
67 | SetMaxVtxRadius(0,3.5); | |
68 | SetMaxVtxRadius(1,6.5); | |
69 | SetMaxVtxRadius(2,14.5); | |
70 | SetMaxVtxRadius(3,23.5); | |
71 | SetMaxVtxRadius(4,37.5); | |
72 | SetMaxVtxRadius(5,42.5); | |
73 | */ | |
74 | SetMaxVtxRadius(0,5.5); | |
75 | SetMaxVtxRadius(1,8.5); | |
76 | SetMaxVtxRadius(2,18.5); | |
77 | SetMaxVtxRadius(3,28.5); | |
78 | SetMaxVtxRadius(4,39.5); | |
79 | SetMaxVtxRadius(5,48.5); | |
80 | ||
81 | SetMaxDistOnOuterLayer(); | |
82 | SetMinDist2Vtxs(); | |
83 | } | |
84 | //-------------------------------------------------------------------------- | |
85 | AliESDVertex* AliITSVertexerCosmics::FindVertexForCurrentEvent(TTree *itsClusterTree) | |
86 | { | |
87 | // Defines the AliESDVertex for the current event | |
88 | ||
89 | fCurrentVertex = 0; | |
90 | ||
91 | TClonesArray *recpoints=new TClonesArray("AliITSRecPoint",10000); | |
92 | itsClusterTree->SetBranchAddress("ITSRecPoints",&recpoints); | |
93 | ||
94 | Int_t lay,lad,det; | |
95 | ||
96 | Double_t pos[3]={0.,0.,0.}; | |
97 | Double_t err[3]={100.,100.,100.}; | |
98 | Int_t ncontributors = -1; | |
99 | ||
100 | // Search for innermost layer with at least two clusters | |
101 | // on two different modules | |
102 | Int_t ilayer=0,ilayer2=0; | |
103 | Int_t nHitModulesSPDinner=0; | |
104 | while(ilayer<AliITSgeomTGeo::GetNLayers()) { | |
105 | if(AliITSReconstructor::GetRecoParam()->GetLayersToSkip(ilayer)) { | |
106 | ilayer++; | |
107 | continue; | |
108 | } | |
109 | Int_t nHitModules=0; | |
110 | for(Int_t imodule=fFirst[ilayer]; imodule<=fLast[ilayer]; imodule++) { | |
111 | itsClusterTree->GetEvent(imodule); | |
112 | AliITSgeomTGeo::GetModuleId(imodule,lay,lad,det); | |
113 | lay -= 1; // AliITSgeomTGeo gives layer from 1 to 6, we want 0 to 5 | |
114 | if(lay!=ilayer) AliFatal("Layer mismatch!"); | |
115 | if(recpoints->GetEntriesFast()>0) nHitModules++; | |
116 | } | |
117 | if(ilayer==0) nHitModulesSPDinner=nHitModules; | |
118 | if(nHitModules>=2) break; | |
119 | ilayer++; | |
120 | } | |
121 | ||
122 | ilayer2=ilayer+1; | |
123 | while(ilayer2<6) { | |
124 | if(!AliITSReconstructor::GetRecoParam()->GetLayersToSkip(ilayer2)) break; | |
125 | ilayer2++; | |
126 | } | |
127 | ||
128 | // try tracklet on SPD2 and point on SPD1 | |
129 | if(ilayer==1 && !AliITSReconstructor::GetRecoParam()->GetLayersToSkip(0) && | |
130 | nHitModulesSPDinner>0) { ilayer=0; ilayer2=1; } | |
131 | ||
132 | if(ilayer>4 || ilayer2>5) { | |
133 | AliWarning("Not enough clusters"); | |
134 | delete recpoints; | |
135 | fCurrentVertex = new AliESDVertex(pos,err,"cosmics"); | |
136 | fCurrentVertex->SetTitle("cosmics fake vertex (failed)"); | |
137 | fCurrentVertex->SetNContributors(ncontributors); | |
138 | return fCurrentVertex; | |
139 | } | |
140 | ||
141 | ||
142 | const Int_t arrSize = 1000; | |
143 | Float_t xclInnLay[arrSize],yclInnLay[arrSize],zclInnLay[arrSize],modclInnLay[arrSize]; | |
144 | Float_t e2xclInnLay[arrSize],e2yclInnLay[arrSize],e2zclInnLay[arrSize]; | |
145 | Float_t e2xclOutLay[arrSize],e2yclOutLay[arrSize],e2zclOutLay[arrSize]; | |
146 | Int_t nclInnLayStored=0; | |
147 | Float_t xclOutLay[arrSize],yclOutLay[arrSize],zclOutLay[arrSize],modclOutLay[arrSize]; | |
148 | Int_t nclOutLayStored=0; | |
149 | Int_t nRecPoints,nRecPointsInnLay=0; | |
150 | ||
151 | Float_t gc[3],gcov[6]; | |
152 | ||
153 | Float_t matchOutLayValue; | |
154 | Float_t distxyInnLay,distxyInnLayBest=0.; | |
155 | Double_t p1[3],p2[3],p3[3]; | |
156 | ||
157 | Float_t xvtx,yvtx,zvtx,rvtx; | |
158 | Int_t i1InnLayBest=-1,i2InnLayBest=-1; | |
159 | ||
160 | ||
161 | // Collect clusters in the selected layer and the outer one | |
162 | for(Int_t imodule=fFirst[ilayer]; imodule<=fLast[ilayer2]; imodule++) { | |
163 | itsClusterTree->GetEvent(imodule); | |
164 | AliITSgeomTGeo::GetModuleId(imodule,lay,lad,det); | |
165 | lay -= 1; // AliITSgeomTGeo gives layer from 1 to 6, we want 0 to 5 | |
166 | nRecPoints=recpoints->GetEntriesFast(); | |
167 | if(imodule<=fLast[ilayer]) nRecPointsInnLay += nRecPoints; | |
168 | //printf("cosmics: module %d clusters %d\n",imodule,nRecPoints); | |
169 | for(Int_t irp=0; irp<nRecPoints; irp++) { | |
170 | AliITSRecPoint *rp=(AliITSRecPoint*)recpoints->UncheckedAt(irp); | |
171 | // Local coordinates of this recpoint | |
172 | rp->GetGlobalXYZ(gc); | |
173 | if(lay==ilayer) { // store InnLay clusters | |
174 | xclInnLay[nclInnLayStored]=gc[0]; | |
175 | yclInnLay[nclInnLayStored]=gc[1]; | |
176 | zclInnLay[nclInnLayStored]=gc[2]; | |
177 | rp->GetGlobalCov(gcov); | |
178 | e2xclInnLay[nclInnLayStored]=gcov[0]; | |
179 | e2yclInnLay[nclInnLayStored]=gcov[3]; | |
180 | e2zclInnLay[nclInnLayStored]=gcov[5]; | |
181 | modclInnLay[nclInnLayStored]=imodule; | |
182 | nclInnLayStored++; | |
183 | } | |
184 | if(lay==ilayer2) { // store OutLay clusters | |
185 | xclOutLay[nclOutLayStored]=gc[0]; | |
186 | yclOutLay[nclOutLayStored]=gc[1]; | |
187 | zclOutLay[nclOutLayStored]=gc[2]; | |
188 | rp->GetGlobalCov(gcov); | |
189 | e2xclOutLay[nclOutLayStored]=gcov[0]; | |
190 | e2yclOutLay[nclOutLayStored]=gcov[3]; | |
191 | e2zclOutLay[nclOutLayStored]=gcov[5]; | |
192 | modclOutLay[nclOutLayStored]=imodule; | |
193 | nclOutLayStored++; | |
194 | } | |
195 | if(nclInnLayStored>arrSize || nclOutLayStored>arrSize) { | |
196 | //AliFatal("More than arrSize clusters per layer"); | |
197 | AliWarning("Too many clusters per layer"); | |
198 | delete recpoints; | |
199 | fCurrentVertex = new AliESDVertex(pos,err,"cosmics"); | |
200 | fCurrentVertex->SetTitle("cosmics fake vertex (failed)"); | |
201 | fCurrentVertex->SetNContributors(ncontributors); | |
202 | return fCurrentVertex; | |
203 | } | |
204 | }// end clusters in a module | |
205 | }// end modules | |
206 | ||
207 | ||
208 | Int_t i1InnLay,i2InnLay,iOutLay; | |
209 | ||
210 | // build fake vertices | |
211 | //printf("Building tracklets on layer %d\n",ilayer); | |
212 | ||
213 | // InnLay - first cluster | |
214 | for(i1InnLay=0; i1InnLay<nclInnLayStored; i1InnLay++) { | |
215 | p1[0]=xclInnLay[i1InnLay]; | |
216 | p1[1]=yclInnLay[i1InnLay]; | |
217 | p1[2]=zclInnLay[i1InnLay]; | |
218 | // InnLay - second cluster | |
219 | for(i2InnLay=i1InnLay+1; i2InnLay<nclInnLayStored; i2InnLay++) { | |
220 | if(modclInnLay[i1InnLay]==modclInnLay[i2InnLay]) continue; | |
221 | p2[0]=xclInnLay[i2InnLay]; | |
222 | p2[1]=yclInnLay[i2InnLay]; | |
223 | p2[2]=zclInnLay[i2InnLay]; | |
224 | // look for point on OutLay | |
225 | AliStrLine innLayline(p1,p2,kTRUE); | |
226 | for(iOutLay=0; iOutLay<nclOutLayStored; iOutLay++) { | |
227 | p3[0]=xclOutLay[iOutLay]; | |
228 | p3[1]=yclOutLay[iOutLay]; | |
229 | p3[2]=zclOutLay[iOutLay]; | |
230 | //printf("(%f,%f) (%f,%f) (%f,%f) %f\n",p1[0],p1[1],p2[0],p2[1],p3[0],p3[1],innLayline.GetDistFromPoint(p3)); | |
231 | matchOutLayValue=innLayline.GetDistFromPoint(p3); | |
232 | distxyInnLay = (p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1]); | |
233 | if(matchOutLayValue<fMaxDistOnOuterLayer && | |
234 | distxyInnLay>distxyInnLayBest) { | |
235 | //printf("found\n"); | |
236 | distxyInnLayBest=distxyInnLay; | |
237 | i1InnLayBest=i1InnLay; | |
238 | i2InnLayBest=i2InnLay; | |
239 | } | |
240 | } | |
241 | } // InnLay - second cluster | |
242 | } // InnLay - first cluster | |
243 | ||
244 | if(i1InnLayBest>-1 && i2InnLayBest>-1) { | |
245 | xvtx = 0.5*(xclInnLay[i1InnLayBest]+xclInnLay[i2InnLayBest]); | |
246 | yvtx = 0.5*(yclInnLay[i1InnLayBest]+yclInnLay[i2InnLayBest]); | |
247 | zvtx = 0.5*(zclInnLay[i1InnLayBest]+zclInnLay[i2InnLayBest]); | |
248 | rvtx = TMath::Sqrt(xvtx*xvtx+yvtx*yvtx); | |
249 | if(rvtx<fMaxVtxRadius[ilayer]) { | |
250 | ncontributors = ilayer; | |
251 | pos[0] = xvtx; | |
252 | pos[1] = yvtx; | |
253 | pos[2] = zvtx; | |
254 | err[0]=TMath::Sqrt(0.25*(e2xclInnLay[i1InnLayBest]+e2xclInnLay[i2InnLayBest])); | |
255 | err[1]=TMath::Sqrt(0.25*(e2yclInnLay[i1InnLayBest]+e2yclInnLay[i2InnLayBest])); | |
256 | err[2]=TMath::Sqrt(0.25*(e2zclInnLay[i1InnLayBest]+e2zclInnLay[i2InnLayBest])); | |
257 | } | |
258 | ||
259 | } else { // give it a try exchanging InnLay and OutLay | |
260 | ||
261 | // OutLay - first cluster | |
262 | for(i1InnLay=0; i1InnLay<nclOutLayStored; i1InnLay++) { | |
263 | p1[0]=xclOutLay[i1InnLay]; | |
264 | p1[1]=yclOutLay[i1InnLay]; | |
265 | p1[2]=zclOutLay[i1InnLay]; | |
266 | // OutLay - second cluster | |
267 | for(i2InnLay=i1InnLay+1; i2InnLay<nclOutLayStored; i2InnLay++) { | |
268 | if(modclOutLay[i1InnLay]==modclOutLay[i2InnLay]) continue; | |
269 | p2[0]=xclOutLay[i2InnLay]; | |
270 | p2[1]=yclOutLay[i2InnLay]; | |
271 | p2[2]=zclOutLay[i2InnLay]; | |
272 | // look for point on InnLay | |
273 | AliStrLine outLayline(p1,p2,kTRUE); | |
274 | for(iOutLay=0; iOutLay<nclInnLayStored; iOutLay++) { | |
275 | p3[0]=xclInnLay[iOutLay]; | |
276 | p3[1]=yclInnLay[iOutLay]; | |
277 | p3[2]=zclInnLay[iOutLay]; | |
278 | //printf(" %f\n",InnLayline.GetDistFromPoint(p3)); | |
279 | matchOutLayValue=outLayline.GetDistFromPoint(p3); | |
280 | distxyInnLay = (p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1]); | |
281 | if(matchOutLayValue<fMaxDistOnOuterLayer && | |
282 | distxyInnLay>distxyInnLayBest) { | |
283 | distxyInnLayBest=distxyInnLay; | |
284 | i1InnLayBest=i1InnLay; | |
285 | i2InnLayBest=i2InnLay; | |
286 | } | |
287 | } | |
288 | } // OutLay - second cluster | |
289 | } // OutLay - first cluster | |
290 | ||
291 | if(i1InnLayBest>-1 && i2InnLayBest>-1) { | |
292 | xvtx = 0.5*(xclOutLay[i1InnLayBest]+xclOutLay[i2InnLayBest]); | |
293 | yvtx = 0.5*(yclOutLay[i1InnLayBest]+yclOutLay[i2InnLayBest]); | |
294 | zvtx = 0.5*(zclOutLay[i1InnLayBest]+zclOutLay[i2InnLayBest]); | |
295 | rvtx = TMath::Sqrt(xvtx*xvtx+yvtx*yvtx); | |
296 | if(rvtx<fMaxVtxRadius[ilayer]) { | |
297 | ncontributors = ilayer2; | |
298 | pos[0] = xvtx; | |
299 | pos[1] = yvtx; | |
300 | pos[2] = zvtx; | |
301 | err[0]=TMath::Sqrt(0.25*(e2xclOutLay[i1InnLayBest]+e2xclOutLay[i2InnLayBest])); | |
302 | err[1]=TMath::Sqrt(0.25*(e2yclOutLay[i1InnLayBest]+e2yclOutLay[i2InnLayBest])); | |
303 | err[2]=TMath::Sqrt(0.25*(e2zclOutLay[i1InnLayBest]+e2zclOutLay[i2InnLayBest])); | |
304 | } | |
305 | } | |
306 | } // give it a try exchanging InnLay and OutLay | |
307 | ||
308 | fCurrentVertex = new AliESDVertex(pos,err,"cosmics"); | |
309 | fCurrentVertex->SetTitle("cosmics fake vertex"); | |
310 | fCurrentVertex->SetNContributors(ncontributors); | |
311 | //fCurrentVertex->Print(); | |
312 | if(fComputeMultiplicity) FindMultiplicity(itsClusterTree); | |
313 | ||
314 | delete recpoints; | |
315 | ||
316 | return fCurrentVertex; | |
317 | } | |
318 | ||
319 | //------------------------------------------------------------------------- | |
320 | void AliITSVertexerCosmics::PrintStatus() const | |
321 | { | |
322 | // Print current status | |
323 | printf("=======================================================\n"); | |
324 | printf(" fMaxDistOnOuterLayer: %f\n",fMaxDistOnOuterLayer); | |
325 | printf(" fMaxVtxRadius[0]: %f\n",fMaxVtxRadius[0]); | |
326 | printf(" fMinDist2Vtxs: %f\n",fMinDist2Vtxs); | |
327 | printf("=======================================================\n"); | |
328 | } | |
329 | //------------------------------------------------------------------------- |