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a9e2aefa | 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 | $Log$ | |
d0bfce8d | 18 | Revision 1.4 2000/06/30 10:15:48 gosset |
19 | Changes to EventReconstructor...: | |
20 | precision fit with multiple Coulomb scattering; | |
21 | extrapolation to vertex with Branson correction in absorber (JPC) | |
22 | ||
04b5ea16 | 23 | Revision 1.3 2000/06/25 13:06:39 hristov |
24 | Inline functions moved from *.cxx to *.h files instead of forward declarations | |
25 | ||
9b03f36b | 26 | Revision 1.2 2000/06/15 07:58:48 morsch |
27 | Code from MUON-dev joined | |
28 | ||
a9e2aefa | 29 | Revision 1.1.2.4 2000/06/12 10:10:21 morsch |
30 | Dummy copy constructor and assignment operator added | |
31 | ||
32 | Revision 1.1.2.3 2000/06/09 21:01:16 morsch | |
33 | Make includes consistent with new file structure. | |
34 | ||
35 | Revision 1.1.2.2 2000/06/09 12:58:05 gosset | |
36 | Removed comment beginnings in Log sections of .cxx files | |
37 | Suppressed most violations of coding rules | |
38 | ||
39 | Revision 1.1.2.1 2000/06/07 14:44:53 gosset | |
40 | Addition of files for track reconstruction in C++ | |
41 | */ | |
42 | ||
43 | //__________________________________________________________________________ | |
44 | // | |
45 | // Segment for reconstruction in ALICE dimuon spectrometer: | |
46 | // two hits for reconstruction in the two chambers of one station | |
47 | //__________________________________________________________________________ | |
48 | ||
49 | #include "AliMUONSegment.h" | |
50 | ||
51 | #include "AliMUON.h" | |
52 | #include "AliMUONHitForRec.h" | |
53 | #include "AliMUONTrackParam.h" | |
54 | #include "AliMUONChamber.h" | |
55 | #include "AliRun.h" | |
56 | ||
57 | ClassImp(AliMUONSegment) // Class implementation in ROOT context | |
58 | ||
59 | //__________________________________________________________________________ | |
60 | AliMUONSegment::AliMUONSegment(AliMUONHitForRec* Hit1, AliMUONHitForRec* Hit2) | |
61 | { | |
62 | // Constructor for AliMUONSegment from two HitForRec's, | |
63 | // one, in the first chamber of the station, pointed to by "Hit1", | |
64 | // the other one, in the second chamber of the station, pointed to by "Hit1". | |
65 | // Fills the pointers to both hits, | |
66 | // the slope, the covariance for (coordinate in first chamber, slope), | |
67 | // and the impact parameter at vertex (Z=0), | |
68 | // in bending and non bending planes. | |
69 | // Puts the "fInTrack" flag to "kFALSE". | |
70 | Double_t dz; | |
71 | // pointers to HitForRec's | |
72 | fHitForRecPtr1 = Hit1; | |
73 | fHitForRecPtr2 = Hit2; | |
74 | dz = Hit1->GetZ() - Hit2->GetZ(); | |
75 | // bending plane | |
76 | fBendingCoor = Hit1->GetBendingCoor(); | |
77 | fBendingSlope = (fBendingCoor - Hit2->GetBendingCoor()) / dz; | |
78 | fBendingImpact = fBendingCoor - Hit1->GetZ() * fBendingSlope; | |
79 | fBendingCoorReso2 = Hit1->GetBendingReso2(); | |
80 | fBendingSlopeReso2 = ( Hit1->GetBendingReso2() + | |
81 | Hit2->GetBendingReso2() ) / dz / dz; | |
82 | fBendingCoorSlopeReso2 = Hit1->GetBendingReso2() / dz; | |
83 | // non bending plane | |
84 | fNonBendingCoor = Hit1->GetNonBendingCoor(); | |
85 | fNonBendingSlope = (fNonBendingCoor - Hit2->GetNonBendingCoor()) / dz; | |
86 | fNonBendingImpact = fNonBendingCoor - Hit1->GetZ() * fNonBendingSlope; | |
87 | fNonBendingCoorReso2 = Hit1->GetNonBendingReso2(); | |
88 | fNonBendingSlopeReso2 = ( Hit1->GetNonBendingReso2() + | |
89 | Hit2->GetNonBendingReso2() ) / dz / dz; | |
90 | fNonBendingCoorSlopeReso2 = Hit1->GetNonBendingReso2() / dz; | |
91 | // "fInTrack" flag to "kFALSE" | |
92 | fInTrack = kFALSE; | |
93 | return; | |
94 | } | |
95 | ||
96 | AliMUONSegment::AliMUONSegment (const AliMUONSegment& MUONSegment) | |
97 | { | |
98 | // Dummy copy constructor | |
99 | } | |
100 | ||
101 | AliMUONSegment & AliMUONSegment::operator=(const AliMUONSegment& MUONSegment) | |
102 | { | |
103 | // Dummy assignment operator | |
104 | return *this; | |
105 | } | |
106 | ||
a9e2aefa | 107 | //__________________________________________________________________________ |
108 | Int_t AliMUONSegment::Compare(TObject* Segment) | |
109 | { | |
110 | // "Compare" function to sort with increasing absolute value | |
111 | // of the "impact parameter" in bending plane. | |
112 | // Returns -1 (0, +1) if |impact parameter| of current Segment | |
113 | // is smaller than (equal to, larger than) |impact parameter| of Segment | |
114 | if (TMath::Abs(((AliMUONSegment*)this)->fBendingSlope) | |
115 | < TMath::Abs(((AliMUONSegment*)Segment)->fBendingSlope)) | |
116 | return(-1); | |
117 | // continuous parameter, hence no need for testing equal case | |
118 | else return(+1); | |
119 | } | |
120 | ||
121 | //__________________________________________________________________________ | |
122 | Double_t AliMUONSegment::NormalizedChi2WithSegment(AliMUONSegment* Segment, Double_t Sigma2Cut) | |
123 | { | |
124 | // Calculate the normalized Chi2 between the current Segment (this) | |
125 | // and the Segment pointed to by "Segment", | |
126 | // i.e. the square deviations between the coordinates and the slopes, | |
127 | // in both the bending and the non bending plane, | |
128 | // divided by the variance of the same quantities and by "Sigma2Cut". | |
129 | // Returns 5 if none of the 4 quantities is OK, | |
130 | // something smaller than or equal to 4 otherwise. | |
131 | // Would it be more correct to use a real chi square | |
132 | // including the non diagonal term ???? | |
133 | Double_t chi2, chi2Max, diff, normDiff; | |
134 | chi2 = 0.0; | |
135 | chi2Max = 5.0; | |
136 | // coordinate in bending plane | |
137 | diff = this->fBendingCoor - Segment->fBendingCoor; | |
138 | normDiff = diff * diff / | |
139 | (this->fBendingCoorReso2 + Segment->fBendingCoorReso2) / Sigma2Cut; | |
140 | if (normDiff > 1.0) return chi2Max; | |
141 | chi2 = chi2 + normDiff; | |
142 | // slope in bending plane | |
143 | diff = this->fBendingSlope - Segment->fBendingSlope; | |
144 | normDiff = diff * diff / | |
145 | (this->fBendingSlopeReso2 + Segment->fBendingSlopeReso2) / Sigma2Cut; | |
146 | if (normDiff > 1.0) return chi2Max; | |
147 | chi2 = chi2 + normDiff; | |
148 | // coordinate in non bending plane | |
149 | diff = this->fNonBendingCoor - Segment->fNonBendingCoor; | |
150 | normDiff = diff * diff / | |
151 | (this->fNonBendingCoorReso2 + Segment->fNonBendingCoorReso2) / Sigma2Cut; | |
152 | if (normDiff > 1.0) return chi2Max; | |
153 | chi2 = chi2 + normDiff; | |
154 | // slope in non bending plane | |
155 | diff = this->fNonBendingSlope - Segment->fNonBendingSlope; | |
156 | normDiff = diff * diff / | |
157 | (this->fNonBendingSlopeReso2 + Segment->fNonBendingSlopeReso2) / Sigma2Cut; | |
158 | if (normDiff > 1.0) return chi2Max; | |
159 | chi2 = chi2 + normDiff; | |
160 | return chi2; | |
161 | } | |
162 | ||
163 | //__________________________________________________________________________ | |
164 | AliMUONSegment* AliMUONSegment::CreateSegmentFromLinearExtrapToStation (Int_t Station, Double_t MCSfactor) | |
165 | { | |
166 | // Extrapolates linearly the current Segment (this) to station (0..) "Station". | |
167 | // Multiple Coulomb scattering calculated from "MCSfactor" | |
168 | // corresponding to one chamber, | |
169 | // with one chamber for the coordinate, two chambers for the angle, | |
170 | // due to the arrangement in stations. | |
171 | // Valid from station(1..) 4 to 5 or vice versa. | |
172 | // Returns the pointer to the created AliMUONSegment object | |
173 | // corresponding to this extrapolation. | |
174 | // The caller has the responsibility to delete this object. | |
175 | AliMUONSegment* extrapSegment = new AliMUONSegment(); // creates empty new segment | |
176 | // dZ from first hit of current Segment to first chamber of station "Station" | |
177 | AliMUON *pMUON = (AliMUON*) gAlice->GetModule("MUON"); // necessary ???? | |
178 | Double_t dZ = | |
179 | (&(pMUON->Chamber(2 * Station)))->Z() - (this->fHitForRecPtr1)->GetZ(); | |
180 | // Data in bending plane | |
181 | // coordinate | |
182 | extrapSegment->fBendingCoor = this->fBendingCoor + this->fBendingSlope * dZ; | |
183 | // slope | |
184 | extrapSegment->fBendingSlope = this->fBendingSlope; | |
185 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
186 | extrapSegment->fBendingCoorReso2 = this->fBendingCoorReso2 + | |
187 | (this->fBendingSlopeReso2 + MCSfactor) * dZ * dZ; // missing non diagonal term: "2.0 * this->fBendingCoorSlopeReso2 * dZ" !!!! | |
188 | extrapSegment->fBendingSlopeReso2 = this->fBendingSlopeReso2 + 2.0 * MCSfactor; | |
189 | extrapSegment->fBendingCoorSlopeReso2 = | |
190 | this->fBendingCoorSlopeReso2 + this->fBendingSlopeReso2 * dZ; // missing: contribution from multiple Coulomb scattering !!!! | |
191 | // Data in non bending plane | |
192 | // coordinate | |
193 | extrapSegment->fNonBendingCoor = | |
194 | this->fNonBendingCoor + this->fNonBendingSlope * dZ; | |
195 | // slope | |
196 | extrapSegment->fNonBendingSlope = this->fNonBendingSlope; | |
197 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
198 | extrapSegment->fNonBendingCoorReso2 = this->fNonBendingCoorReso2 + | |
199 | (this->fNonBendingSlopeReso2 + MCSfactor) *dZ * dZ; // missing non diagonal term: "2.0 * this->fNonBendingCoorSlopeReso2 * dZ" !!!! | |
200 | extrapSegment->fNonBendingSlopeReso2 = | |
201 | this->fNonBendingSlopeReso2 + 2.0 * MCSfactor; | |
202 | extrapSegment->fNonBendingCoorSlopeReso2 = | |
203 | this->fNonBendingCoorSlopeReso2 + this->fNonBendingSlopeReso2 * dZ; // missing: contribution from multiple Coulomb scattering !!!! | |
204 | return extrapSegment; | |
205 | } | |
206 | ||
207 | //__________________________________________________________________________ | |
208 | AliMUONHitForRec* AliMUONSegment::CreateHitForRecFromLinearExtrapToChamber (Int_t Chamber, Double_t MCSfactor) | |
209 | { | |
210 | // Extrapolates linearly the current Segment (this) to chamber(0..) "Chamber". | |
211 | // Multiple Coulomb scattering calculated from "MCSfactor" | |
212 | // corresponding to one chamber. | |
213 | // Valid from station(1..) 4 to 5 or vice versa. | |
214 | // Returns the pointer to the created AliMUONHitForRec object | |
215 | // corresponding to this extrapolation. | |
216 | // The caller has the responsibility to delete this object. | |
217 | AliMUONHitForRec* extrapHitForRec = new AliMUONHitForRec(); // creates empty new HitForRec | |
218 | // dZ from first hit of current Segment to chamber | |
219 | AliMUON *pMUON = (AliMUON*) gAlice->GetModule("MUON"); // necessary ???? | |
220 | Double_t dZ = | |
221 | (&(pMUON->Chamber(Chamber)))->Z() - (this->fHitForRecPtr1)->GetZ(); | |
222 | // Data in bending plane | |
223 | // coordinate | |
224 | extrapHitForRec->SetBendingCoor(this->fBendingCoor + this->fBendingSlope * dZ); | |
225 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
226 | extrapHitForRec->SetBendingReso2(this->fBendingCoorReso2 + | |
227 | (this->fBendingSlopeReso2 + MCSfactor) * dZ * dZ); // missing non diagonal term: "2.0 * this->fBendingCoorSlopeReso2 * dZ" !!!! | |
228 | // Data in non bending plane | |
229 | // coordinate | |
230 | extrapHitForRec ->SetNonBendingCoor(this->fNonBendingCoor + | |
231 | this->fNonBendingSlope * dZ); | |
232 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
233 | extrapHitForRec-> | |
234 | SetNonBendingReso2(this->fNonBendingCoorReso2 + | |
235 | (this->fNonBendingSlopeReso2 + MCSfactor) * dZ * dZ); // missing non diagonal term: "2.0 * this->fNonBendingCoorSlopeReso2 * dZ" !!!! | |
236 | return extrapHitForRec; | |
237 | } | |
238 | ||
239 | //__________________________________________________________________________ | |
04b5ea16 | 240 | void AliMUONSegment::UpdateFromStationTrackParam(AliMUONTrackParam *TrackParam, Double_t MCSfactor, Double_t Dz1, Double_t Dz2, Double_t Dz3, Int_t Station, Double_t InverseMomentum) |
a9e2aefa | 241 | { |
242 | // Fill data members with values calculated from the array of track parameters | |
243 | // pointed to by "TrackParam" (index = 0 and 1 for first and second chambers | |
244 | // of the station, respectively). | |
245 | // Multiple Coulomb scattering is taking into account with "MCSfactor" | |
246 | // corresponding to one chamber, | |
247 | // with one chamber for the coordinate, two chambers for the angle, | |
248 | // due to the arrangement in stations. | |
249 | // Resolution coming from: | |
04b5ea16 | 250 | // coordinate in closest station at "Dz1" from current "Station", |
a9e2aefa | 251 | // slope between closest stations, with "Dz2" interval between them, |
04b5ea16 | 252 | // interval "Dz3" between chambers of closest station, |
253 | // extrapolation over "Dz1" from closest station, | |
254 | // "InverseMomentum". | |
a9e2aefa | 255 | // When called, "fBendingCoorReso2" and "fNonBendingCoorReso2" |
256 | // are assumed to be filled | |
257 | // with the variance on bending and non bending coordinates. | |
04b5ea16 | 258 | // The "road" is parametrized from the old reco_muon.F |
259 | // with 8 cm between stations. | |
a9e2aefa | 260 | AliMUONTrackParam *param0; |
d0bfce8d | 261 | // Double_t cReso2, sReso2; |
04b5ea16 | 262 | // parameters to define the widths of the searching roads in station 0,1,2 |
263 | // width = p0 + p1/ (momentum)^2 | |
264 | // station number: 0 1 2 | |
d0bfce8d | 265 | // static Double_t p0BendingCoor[3] = { 6.43e-2, 1.64e-2, 0.034 }; |
266 | // static Double_t p1BendingCoor[3] = { 986., 821., 446. }; | |
267 | // static Double_t p0BendingSlope[3] = { 3.54e-6, 3.63e-6, 3.6e-6 }; | |
268 | // static Double_t p1BendingSlope[3] = { 4.49e-3, 4.8e-3, 0.011 }; | |
269 | // static Double_t p0NonBendingCoor[3] = { 4.66e-2, 4.83e-2, 0.049 }; | |
270 | // static Double_t p1NonBendingCoor[3] = { 1444., 866., 354. }; | |
271 | // static Double_t p0NonBendingSlope[3] = { 6.14e-4, 6.49e-4, 6.85e-4 }; | |
272 | // static Double_t p1NonBendingSlope[3] = { 0., 0., 0. }; | |
273 | ||
274 | static Double_t p0BendingCoor[3] = { 6.43e-2, 6.43e-2, 6.43e-2 }; | |
275 | static Double_t p1BendingCoor[3] = { 986., 986., 986. }; | |
276 | static Double_t p0BendingSlope[3] = { 3.6e-6, 3.6e-6, 3.6e-6 }; | |
277 | static Double_t p1BendingSlope[3] = { 1.1e-2, 1.1e-2, 1.1e-2 }; | |
278 | static Double_t p0NonBendingCoor[3] = { 0.049, 0.049, 0.049 }; | |
279 | static Double_t p1NonBendingCoor[3] = { 1444., 1444., 1444. }; | |
280 | static Double_t p0NonBendingSlope[3] = { 6.8e-4, 6.8e-4, 6.8e-4 }; | |
281 | static Double_t p1NonBendingSlope[3] = { 0., 0., 0. }; | |
a9e2aefa | 282 | param0 = &(TrackParam[0]); |
04b5ea16 | 283 | |
284 | // OLD version | |
285 | // // Bending plane | |
286 | // fBendingCoor = param0->GetBendingCoor(); // coordinate | |
287 | // fBendingSlope = param0->GetBendingSlope(); // slope | |
288 | // cReso2 = fBendingCoorReso2; | |
289 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
290 | // fBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
291 | // fBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
292 | // // Non bending plane | |
293 | // fNonBendingCoor = param0->GetNonBendingCoor(); // coordinate | |
294 | // fNonBendingSlope = param0->GetNonBendingSlope(); // slope | |
295 | // cReso2 = fNonBendingCoorReso2; | |
296 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
297 | // fNonBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
298 | // fNonBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
299 | ||
300 | // Coordinate and slope | |
a9e2aefa | 301 | // Bending plane |
302 | fBendingCoor = param0->GetBendingCoor(); // coordinate | |
303 | fBendingSlope = param0->GetBendingSlope(); // slope | |
a9e2aefa | 304 | // Non bending plane |
305 | fNonBendingCoor = param0->GetNonBendingCoor(); // coordinate | |
306 | fNonBendingSlope = param0->GetNonBendingSlope(); // slope | |
04b5ea16 | 307 | |
308 | // Resolutions | |
309 | // cReso2 and sReso2 have to be subtracted here from the parametrization | |
310 | // because they are added in the functions "NormalizedChi2WithSegment" | |
311 | // and "NormalizedChi2WithHitForRec" | |
312 | // Bending plane | |
d0bfce8d | 313 | // cReso2 = fBendingCoorReso2; |
314 | // sReso2 = (2. * cReso2 )/ (Dz3*Dz3) ; | |
315 | fBendingCoorReso2 = p0BendingCoor[Station] + p1BendingCoor[Station]*InverseMomentum*InverseMomentum ; // - cReso2 | |
316 | fBendingSlopeReso2 = p0BendingSlope[Station] + p1BendingSlope[Station]*InverseMomentum*InverseMomentum; // - sReso2; | |
04b5ea16 | 317 | // Non bending plane |
d0bfce8d | 318 | // cReso2 = fNonBendingCoorReso2; |
319 | // sReso2 = (2. * cReso2 )/ (Dz3*Dz3) ; | |
320 | fNonBendingCoorReso2 = p0NonBendingCoor[Station] + p1NonBendingCoor[Station]*InverseMomentum*InverseMomentum; // - cReso2; | |
321 | fNonBendingSlopeReso2 = p0NonBendingSlope[Station] + p1NonBendingSlope[Station]*InverseMomentum*InverseMomentum; // - sReso2; | |
a9e2aefa | 322 | return; |
323 | } | |
04b5ea16 | 324 | |
325 | // OLD function, with roads automatically calculated instead from being parametrized | |
326 | // kept because it would be a better solution, | |
327 | // if one can really find the right values. | |
328 | // //__________________________________________________________________________ | |
329 | // void AliMUONSegment::UpdateFromStationTrackParam(AliMUONTrackParam *TrackParam, Double_t MCSfactor, Double_t Dz1, Double_t Dz2) | |
330 | // { | |
331 | // // Fill data members with values calculated from the array of track parameters | |
332 | // // pointed to by "TrackParam" (index = 0 and 1 for first and second chambers | |
333 | // // of the station, respectively). | |
334 | // // Multiple Coulomb scattering is taking into account with "MCSfactor" | |
335 | // // corresponding to one chamber, | |
336 | // // with one chamber for the coordinate, two chambers for the angle, | |
337 | // // due to the arrangement in stations. | |
338 | // // Resolution coming from: | |
339 | // // coordinate in closest station at "Dz1", | |
340 | // // slope between closest stations, with "Dz2" interval between them, | |
341 | // // extrapolation over "Dz" from closest station. | |
342 | // // When called, "fBendingCoorReso2" and "fNonBendingCoorReso2" | |
343 | // // are assumed to be filled | |
344 | // // with the variance on bending and non bending coordinates. | |
345 | // AliMUONTrackParam *param0; | |
346 | // Double_t cReso2, sReso2; | |
347 | // param0 = &(TrackParam[0]); | |
348 | // // Bending plane | |
349 | // fBendingCoor = param0->GetBendingCoor(); // coordinate | |
350 | // fBendingSlope = param0->GetBendingSlope(); // slope | |
351 | // cReso2 = fBendingCoorReso2; | |
352 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
353 | // fBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
354 | // fBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
355 | // // Non bending plane | |
356 | // fNonBendingCoor = param0->GetNonBendingCoor(); // coordinate | |
357 | // fNonBendingSlope = param0->GetNonBendingSlope(); // slope | |
358 | // cReso2 = fNonBendingCoorReso2; | |
359 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
360 | // fNonBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
361 | // fNonBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
362 | // return; | |
363 | // } |