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9bf6860b | 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 | // $Id$ | |
17 | ||
18 | #include "AliMUONTriggerTrackToTrackerClusters.h" | |
19 | ||
20 | ///\class AliMUONTriggerTrackToTrackerClusters | |
21 | /// | |
22 | /// Class to convert trigger tracks into "fake" clusters in stations 4 and 5 | |
23 | /// | |
24 | /// Only intent is to be able to reconstruct data where stations 4 and 5 were | |
25 | /// not functionning, typically early cosmic runs | |
26 | /// | |
27 | ///\author Laurent Aphecetche, Subatech | |
28 | ||
29 | #include "AliCodeTimer.h" | |
30 | #include "AliLog.h" | |
31 | #include "AliMUONConstants.h" | |
32 | #include "AliMUONGeometryTransformer.h" | |
33 | #include "AliMUONTrack.h" | |
34 | #include "AliMUONTrackExtrap.h" | |
35 | #include "AliMUONTriggerTrack.h" | |
36 | #include "AliMUONVCluster.h" | |
37 | #include "AliMUONVClusterStore.h" | |
38 | #include "AliMUONVTriggerTrackStore.h" | |
39 | #include "AliMpArea.h" | |
40 | #include "AliMpDEManager.h" | |
41 | #include <TMath.h> | |
42 | ||
43 | ///\cond CLASSIMP | |
44 | ClassImp(AliMUONTriggerTrackToTrackerClusters) | |
45 | ///\endcond | |
46 | ||
47 | //_____________________________________________________________________________ | |
48 | AliMUONTriggerTrackToTrackerClusters::AliMUONTriggerTrackToTrackerClusters(const AliMUONGeometryTransformer& transformer, | |
49 | AliMUONVTriggerTrackStore* trackStore) | |
50 | : TObject(), fTransformer(transformer), fTriggerTrackStore(trackStore) | |
51 | { | |
52 | /// ctor. We do not take ownership of the trigger track store. | |
53 | } | |
54 | ||
55 | //_____________________________________________________________________________ | |
56 | AliMUONTriggerTrackToTrackerClusters::~AliMUONTriggerTrackToTrackerClusters() | |
57 | { | |
58 | /// dtor | |
59 | } | |
60 | ||
61 | //_____________________________________________________________________________ | |
62 | Int_t | |
63 | AliMUONTriggerTrackToTrackerClusters::DetElemId(Int_t chamber, Double_t x, Double_t y, | |
64 | Double_t ex, Double_t ey, | |
65 | Double_t& z) const | |
66 | { | |
67 | /// Find in which detection element (x,y) (global) position is. | |
68 | ||
69 | AliMpDEIterator it; | |
70 | ||
71 | AliMpArea a( TVector2(x,y), TVector2(ex,ey) ); | |
72 | ||
73 | it.First(chamber); | |
74 | ||
75 | while ( !it.IsDone() ) | |
76 | { | |
77 | Int_t detElemId = it.CurrentDEId(); | |
78 | ||
79 | AliMpArea* area = fTransformer.GetDEArea(detElemId); | |
80 | ||
81 | if ( area->Overlap(a) ) | |
82 | { | |
83 | // get z of the center of that DE. | |
84 | Double_t dummyx, dummyy; | |
85 | fTransformer.Local2Global(detElemId,0,0,0,dummyx,dummyy,z); | |
86 | return detElemId; | |
87 | } | |
88 | it.Next(); | |
89 | } | |
90 | ||
91 | return -1; | |
92 | } | |
93 | ||
94 | //_____________________________________________________________________________ | |
95 | Int_t | |
96 | AliMUONTriggerTrackToTrackerClusters::GenerateClusters(Int_t iChamber, | |
97 | AliMUONVClusterStore& clusterStore) const | |
98 | { | |
99 | /// Generate clusters in given chamber | |
100 | /// Return the number of clusters added to the clusterStore | |
101 | ||
102 | AliCodeTimerAuto(Form("Chamber %d",iChamber)); | |
103 | ||
104 | TIter next(fTriggerTrackStore->CreateIterator()); | |
105 | ||
106 | AliMUONTriggerTrack* track; | |
107 | Int_t nadded(0); | |
108 | ||
109 | while ( ( track = static_cast<AliMUONTriggerTrack*>(next()) ) ) | |
110 | { | |
111 | nadded += GenerateClusters(iChamber,*track,clusterStore); | |
112 | } | |
113 | return nadded; | |
114 | } | |
115 | ||
116 | //_____________________________________________________________________________ | |
117 | Int_t | |
118 | AliMUONTriggerTrackToTrackerClusters::GenerateClusters(Int_t iChamber, | |
119 | const AliMUONTriggerTrack& track, | |
120 | AliMUONVClusterStore& clusterStore) const | |
121 | { | |
122 | /// From a trigger track, generate 1 cluster in given chamber | |
123 | ||
124 | /// Get a (rough) guestimate of the track momentum | |
125 | ||
126 | Int_t nadded(0); | |
127 | ||
128 | Double_t z = AliMUONConstants::DefaultChamberZ(10); | |
129 | ||
130 | Double_t bendingCoord = track.GetY11(); | |
131 | Double_t bendingSlope = TMath::Tan(track.GetThetay()); | |
132 | ||
133 | Double_t bendingImpact = bendingCoord - z * bendingSlope; | |
134 | ||
135 | AliDebug(1,Form("TriggerTrack impact parameter=%e",bendingImpact)); | |
136 | ||
137 | // StdoutToAliDebug(1,track.Print()); | |
138 | ||
139 | Double_t inverseBendingMomentum = 1. / AliMUONTrackExtrap::GetBendingMomentumFromImpactParam(bendingImpact); | |
140 | ||
141 | // Construct an AliMUONTrackParam from the trigger track, in order to be able to extrapolate it | |
142 | // to chambers 6..9 planes. | |
143 | ||
144 | AliMUONTrackParam trackParam; | |
145 | ||
146 | trackParam.SetZ(z); | |
147 | trackParam.SetNonBendingCoor(track.GetX11()); | |
148 | trackParam.SetNonBendingSlope(TMath::Tan(track.GetThetax())); | |
149 | trackParam.SetBendingCoor(bendingCoord); | |
150 | trackParam.SetBendingSlope(bendingSlope); | |
151 | trackParam.SetInverseBendingMomentum(inverseBendingMomentum); | |
152 | ||
153 | Double_t dZ = TMath::Abs(AliMUONConstants::DefaultChamberZ(12) - AliMUONConstants::DefaultChamberZ(10)); | |
154 | ||
155 | Double_t sigmaX = AliMUONConstants::TriggerNonBendingReso(); | |
156 | ||
157 | Double_t sigmaY = AliMUONConstants::TriggerBendingReso(); | |
158 | ||
159 | // Compute and set track parameters covariances | |
160 | TMatrixD paramCov(5,5); | |
161 | paramCov.Zero(); | |
162 | ||
163 | // Non bending plane | |
164 | paramCov(0,0) = sigmaX*sigmaX; | |
165 | paramCov(0,1) = -sigmaX/dZ; | |
166 | paramCov(1,0) = paramCov(0,1); | |
167 | ||
168 | paramCov(1,1) = 2.0*sigmaX/dZ/dZ; | |
169 | ||
170 | // Bending plane | |
171 | paramCov(2,2) = sigmaY*sigmaY; | |
172 | paramCov(2,3) = -sigmaY/dZ; | |
173 | paramCov(3,2) = paramCov(2,3); | |
174 | ||
175 | paramCov(3,3) = 2.0*sigmaY/dZ/dZ; | |
176 | ||
177 | // Inverse bending momentum (50% error) | |
178 | paramCov(4,4) = 0.5*inverseBendingMomentum * 0.5*inverseBendingMomentum; | |
179 | ||
180 | // Set covariances | |
181 | trackParam.SetCovariances(paramCov); | |
182 | ||
183 | // Now we extrapolate this trackParam to chambers 6 -> 9 | |
184 | ||
185 | const Float_t kFilterThickness = TMath::Abs(AliMUONConstants::MuonFilterZEnd()-AliMUONConstants::MuonFilterZBeg()); // cm | |
186 | ||
187 | Int_t nclusters = clusterStore.GetSize(); | |
188 | ||
189 | AliMUONTrackParam tp(trackParam); | |
190 | ||
191 | Double_t zg = AliMUONConstants::DefaultChamberZ(iChamber); | |
192 | AliMUONTrackExtrap::ExtrapToZCov(&tp, zg); // Extrap to iChamber | |
193 | ||
194 | AliMUONTrackExtrap::AddMCSEffect(&tp, kFilterThickness, AliMUONConstants::MuonFilterX0()); // Add MCS effects | |
195 | ||
196 | AliDebug(1,Form("iChamber=%d",iChamber)); | |
197 | ||
198 | StdoutToAliDebug(1,tp.Print("FULLCOV");); | |
199 | ||
200 | Double_t x = tp.GetNonBendingCoor(); | |
201 | Double_t y = tp.GetBendingCoor(); | |
202 | const TMatrixD& cov = tp.GetCovariances(); | |
203 | Double_t ex = TMath::Sqrt(cov(0,0)); | |
204 | Double_t ey = TMath::Sqrt(cov(2,2)); | |
205 | ||
206 | Double_t zde; | |
207 | ||
208 | Int_t detElemId = DetElemId(iChamber,x,y,ex,ey,zde); | |
209 | ||
210 | AliDebug(1,Form("zg = %e zde = %e",zg,zde)); | |
211 | ||
212 | if ( AliMpDEManager::IsValidDetElemId(detElemId) ) | |
213 | { | |
214 | AliMUONVCluster* rawCluster = clusterStore.Add(AliMpDEManager::GetChamberId(detElemId), detElemId, nclusters); | |
215 | ||
216 | ++nclusters; | |
217 | ++nadded; | |
218 | ||
219 | rawCluster->SetCharge(100.0); | |
220 | rawCluster->SetXYZ(x, y, zg); | |
221 | rawCluster->SetErrXY(ex,ey); | |
222 | } | |
223 | else | |
224 | { | |
225 | AliWarning(Form("No DE found at xg=%e yg=%e",detElemId,x,y)); | |
226 | } | |
227 | ||
228 | return nadded; | |
229 | } |