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87594435 | 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 | ||
acd84897 | 16 | /* $Id$ */ |
fb17acd4 | 17 | |
87594435 | 18 | //------------------------------------------------------------------------- |
19 | // Implementation of the AliKalmanTrack class | |
066782e8 | 20 | // that is the base for AliTPCtrack, AliITStrackV2 and AliTRDtrack |
87594435 | 21 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch |
22 | //------------------------------------------------------------------------- | |
6c94f330 | 23 | #include <TGeoManager.h> |
87594435 | 24 | #include "AliKalmanTrack.h" |
87594435 | 25 | |
26 | ClassImp(AliKalmanTrack) | |
27 | ||
e2afb3b6 | 28 | //_______________________________________________________________________ |
6c94f330 | 29 | AliKalmanTrack::AliKalmanTrack():AliExternalTrackParam(), |
e2afb3b6 | 30 | fLab(-3141593), |
68b8060b | 31 | fFakeRatio(0), |
e2afb3b6 | 32 | fChi2(0), |
304864ab | 33 | fMass(AliPID::ParticleMass(AliPID::kPion)), |
90e48c0c | 34 | fN(0), |
35 | fStartTimeIntegral(kFALSE), | |
36 | fIntegratedLength(0) | |
e2afb3b6 | 37 | { |
116cbefd | 38 | // |
39 | // Default constructor | |
40 | // | |
c84a5e9e | 41 | |
7d0f8548 | 42 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; |
e2afb3b6 | 43 | } |
44 | ||
45 | //_______________________________________________________________________ | |
46 | AliKalmanTrack::AliKalmanTrack(const AliKalmanTrack &t): | |
6c94f330 | 47 | AliExternalTrackParam(t), |
e2afb3b6 | 48 | fLab(t.fLab), |
babd135a | 49 | fFakeRatio(t.fFakeRatio), |
e2afb3b6 | 50 | fChi2(t.fChi2), |
51 | fMass(t.fMass), | |
90e48c0c | 52 | fN(t.fN), |
53 | fStartTimeIntegral(t.fStartTimeIntegral), | |
54 | fIntegratedLength(t.fIntegratedLength) | |
e2afb3b6 | 55 | { |
116cbefd | 56 | // |
57 | // Copy constructor | |
58 | // | |
74f9526e | 59 | |
c84a5e9e | 60 | for (Int_t i=0; i<AliPID::kSPECIES; i++) |
61 | fIntegratedTime[i] = t.fIntegratedTime[i]; | |
74f9526e | 62 | } |
c5507f6d | 63 | |
74f9526e | 64 | //_______________________________________________________________________ |
65 | void AliKalmanTrack::StartTimeIntegral() | |
66 | { | |
49a7a79a | 67 | // Sylwester Radomski, GSI |
68 | // S.Radomski@gsi.de | |
74f9526e | 69 | // |
70 | // Start time integration | |
71 | // To be called at Vertex by ITS tracker | |
72 | // | |
73 | ||
74 | //if (fStartTimeIntegral) | |
f37d970d | 75 | // AliWarning("Reseting Recorded Time."); |
74f9526e | 76 | |
77 | fStartTimeIntegral = kTRUE; | |
304864ab | 78 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; |
74f9526e | 79 | fIntegratedLength = 0; |
80 | } | |
7d0f8548 | 81 | |
74f9526e | 82 | //_______________________________________________________________________ |
83 | void AliKalmanTrack:: AddTimeStep(Double_t length) | |
84 | { | |
85 | // | |
86 | // Add step to integrated time | |
87 | // this method should be called by a sublasses at the end | |
88 | // of the PropagateTo function or by a tracker | |
89 | // each time step is made. | |
90 | // | |
91 | // If integration not started function does nothing | |
92 | // | |
93 | // Formula | |
94 | // dt = dl * sqrt(p^2 + m^2) / p | |
95 | // p = pT * (1 + tg^2 (lambda) ) | |
96 | // | |
97 | // pt = 1/external parameter [4] | |
98 | // tg lambda = external parameter [3] | |
99 | // | |
100 | // | |
101 | // Sylwester Radomski, GSI | |
102 | // S.Radomski@gsi.de | |
103 | // | |
104 | ||
5d8718b8 | 105 | static const Double_t kcc = 2.99792458e-2; |
74f9526e | 106 | |
107 | if (!fStartTimeIntegral) return; | |
108 | ||
109 | fIntegratedLength += length; | |
110 | ||
74f9526e | 111 | Double_t xr, param[5]; |
112 | Double_t pt, tgl; | |
113 | ||
114 | GetExternalParameters(xr, param); | |
115 | pt = 1/param[4] ; | |
116 | tgl = param[3]; | |
117 | ||
118 | Double_t p = TMath::Abs(pt * TMath::Sqrt(1+tgl*tgl)); | |
119 | ||
120 | if (length > 100) return; | |
121 | ||
304864ab | 122 | for (Int_t i=0; i<AliPID::kSPECIES; i++) { |
74f9526e | 123 | |
304864ab | 124 | Double_t mass = AliPID::ParticleMass(i); |
74f9526e | 125 | Double_t correction = TMath::Sqrt( pt*pt * (1 + tgl*tgl) + mass * mass ) / p; |
5d8718b8 | 126 | Double_t time = length * correction / kcc; |
74f9526e | 127 | |
74f9526e | 128 | fIntegratedTime[i] += time; |
129 | } | |
e2afb3b6 | 130 | } |
131 | ||
74f9526e | 132 | //_______________________________________________________________________ |
74f9526e | 133 | Double_t AliKalmanTrack::GetIntegratedTime(Int_t pdg) const |
134 | { | |
49a7a79a | 135 | // Sylwester Radomski, GSI |
136 | // S.Radomski@gsi.de | |
74f9526e | 137 | // |
138 | // Return integrated time hypothesis for a given particle | |
139 | // type assumption. | |
140 | // | |
141 | // Input parameter: | |
142 | // pdg - Pdg code of a particle type | |
143 | // | |
144 | ||
145 | ||
146 | if (!fStartTimeIntegral) { | |
f37d970d | 147 | AliWarning("Time integration not started"); |
74f9526e | 148 | return 0.; |
149 | } | |
150 | ||
304864ab | 151 | for (Int_t i=0; i<AliPID::kSPECIES; i++) |
152 | if (AliPID::ParticleCode(i) == TMath::Abs(pdg)) return fIntegratedTime[i]; | |
74f9526e | 153 | |
f37d970d | 154 | AliWarning(Form("Particle type [%d] not found", pdg)); |
74f9526e | 155 | return 0; |
156 | } | |
ae982df3 | 157 | |
158 | void AliKalmanTrack::GetIntegratedTimes(Double_t *times) const { | |
304864ab | 159 | for (Int_t i=0; i<AliPID::kSPECIES; i++) times[i]=fIntegratedTime[i]; |
ae982df3 | 160 | } |
161 | ||
162 | void AliKalmanTrack::SetIntegratedTimes(const Double_t *times) { | |
304864ab | 163 | for (Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i]=times[i]; |
ae982df3 | 164 | } |
165 | ||
4557b520 | 166 | Double_t AliKalmanTrack::MeanMaterialBudget(Double_t *start, Double_t *end, Double_t *mparam) |
167 | { | |
6c94f330 | 168 | // |
4557b520 | 169 | // calculate mean material budget and material properties beween point start and end |
170 | // mparam - returns parameters used for dEdx and multiple scatering | |
171 | // | |
6c94f330 | 172 | // mparam[0] - density mean |
4557b520 | 173 | // mparam[1] - rad length |
174 | // mparam[2] - A mean | |
175 | // mparam[3] - Z mean | |
176 | // mparam[4] - length | |
177 | // mparam[5] - Z/A mean | |
178 | // mparam[6] - number of boundary crosses | |
179 | // | |
6c94f330 | 180 | mparam[0]=0; mparam[1]=1; mparam[2] =0; mparam[3] =0, mparam[4]=0, mparam[5]=0; mparam[6]=0; |
4557b520 | 181 | // |
182 | Double_t bparam[6], lparam[6]; // bparam - total param - lparam - local parameters | |
6c94f330 | 183 | for (Int_t i=0;i<6;i++) bparam[i]=0; // |
4557b520 | 184 | |
185 | if (!gGeoManager) { | |
186 | printf("ERROR: no TGeo\n"); | |
187 | return 0.; | |
188 | } | |
189 | // | |
190 | Double_t length; | |
191 | Double_t dir[3]; | |
192 | length = TMath::Sqrt((end[0]-start[0])*(end[0]-start[0])+ | |
6c94f330 | 193 | (end[1]-start[1])*(end[1]-start[1])+ |
194 | (end[2]-start[2])*(end[2]-start[2])); | |
4557b520 | 195 | mparam[4]=length; |
196 | if (length<TGeoShape::Tolerance()) return 0.0; | |
197 | Double_t invlen = 1./length; | |
198 | dir[0] = (end[0]-start[0])*invlen; | |
199 | dir[1] = (end[1]-start[1])*invlen; | |
200 | dir[2] = (end[2]-start[2])*invlen; | |
201 | // Initialize start point and direction | |
202 | TGeoNode *currentnode = 0; | |
203 | TGeoNode *startnode = gGeoManager->InitTrack(start, dir); | |
204 | // printf("%s length=%f\n",gGeoManager->GetPath(),length); | |
205 | if (!startnode) { | |
206 | printf("ERROR: start point out of geometry\n"); | |
207 | return 0.0; | |
208 | } | |
209 | TGeoMaterial *material = startnode->GetVolume()->GetMedium()->GetMaterial(); | |
210 | lparam[0] = material->GetDensity(); | |
211 | lparam[1] = material->GetRadLen(); | |
212 | lparam[2] = material->GetA(); | |
213 | lparam[3] = material->GetZ(); | |
6c94f330 | 214 | lparam[4] = length; |
4557b520 | 215 | lparam[5] = lparam[3]/lparam[2]; |
216 | if (material->IsMixture()) { | |
217 | lparam[1]*=lparam[0]; // different normalization in the modeler for mixture | |
218 | TGeoMixture * mixture = (TGeoMixture*)material; | |
219 | lparam[5] =0; | |
220 | Double_t sum =0; | |
221 | for (Int_t iel=0;iel<mixture->GetNelements();iel++){ | |
222 | sum += mixture->GetWmixt()[iel]; | |
223 | lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel]; | |
224 | } | |
225 | lparam[5]/=sum; | |
226 | } | |
227 | gGeoManager->FindNextBoundary(length); | |
228 | Double_t snext = gGeoManager->GetStep(); | |
229 | Double_t step = 0.0; | |
230 | // If no boundary within proposed length, return current density | |
231 | if (snext>=length) { | |
6c94f330 | 232 | for (Int_t ip=0;ip<5;ip++) mparam[ip] = lparam[ip]; |
4557b520 | 233 | return lparam[0]; |
234 | } | |
235 | // Try to cross the boundary and see what is next | |
236 | while (length>TGeoShape::Tolerance()) { | |
237 | mparam[6]+=1.; | |
238 | currentnode = gGeoManager->Step(); | |
239 | step += snext+1.E-6; | |
240 | bparam[1] += snext*lparam[1]; | |
241 | bparam[2] += snext*lparam[2]; | |
242 | bparam[3] += snext*lparam[3]; | |
6c94f330 | 243 | bparam[5] += snext*lparam[5]; |
4557b520 | 244 | bparam[0] += snext*lparam[0]; |
245 | ||
246 | if (snext>=length) break; | |
58d96064 | 247 | if (!currentnode) break; |
4557b520 | 248 | // printf("%s snext=%f density=%f bparam[0]=%f\n", gGeoManager->GetPath(),snext,density,bparam[0]); |
249 | if (!gGeoManager->IsEntering()) { | |
250 | gGeoManager->SetStep(1.E-3); | |
251 | currentnode = gGeoManager->Step(); | |
252 | if (!gGeoManager->IsEntering() || !currentnode) { | |
6c94f330 | 253 | // printf("ERROR: cannot cross boundary\n"); |
254 | mparam[0] = bparam[0]/step; | |
255 | mparam[1] = bparam[1]/step; | |
256 | mparam[2] = bparam[2]/step; | |
257 | mparam[3] = bparam[3]/step; | |
258 | mparam[5] = bparam[5]/step; | |
259 | mparam[4] = step; | |
260 | mparam[0] = 0.; // if crash of navigation take mean density 0 | |
261 | mparam[1] = 1000000; // and infinite rad length | |
4557b520 | 262 | return bparam[0]/step; |
263 | } | |
264 | step += 1.E-3; | |
265 | snext += 1.E-3; | |
266 | bparam[0] += lparam[0]*1.E-3; | |
267 | bparam[1] += lparam[1]*1.E-3; | |
268 | bparam[2] += lparam[2]*1.E-3; | |
269 | bparam[3] += lparam[3]*1.E-3; | |
270 | bparam[5] += lparam[5]*1.E-3; | |
271 | } | |
272 | length -= snext; | |
273 | material = currentnode->GetVolume()->GetMedium()->GetMaterial(); | |
274 | lparam[0] = material->GetDensity(); | |
275 | lparam[1] = material->GetRadLen(); | |
276 | lparam[2] = material->GetA(); | |
277 | lparam[3] = material->GetZ(); | |
278 | lparam[5] = lparam[3]/lparam[2]; | |
279 | if (material->IsMixture()) { | |
280 | lparam[1]*=lparam[0]; | |
281 | TGeoMixture * mixture = (TGeoMixture*)material; | |
6c94f330 | 282 | lparam[5]=0; |
4557b520 | 283 | Double_t sum =0; |
284 | for (Int_t iel=0;iel<mixture->GetNelements();iel++){ | |
6c94f330 | 285 | sum+= mixture->GetWmixt()[iel]; |
286 | lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel]; | |
4557b520 | 287 | } |
288 | lparam[5]/=sum; | |
289 | } | |
290 | gGeoManager->FindNextBoundary(length); | |
291 | snext = gGeoManager->GetStep(); | |
6c94f330 | 292 | } |
4557b520 | 293 | mparam[0] = bparam[0]/step; |
294 | mparam[1] = bparam[1]/step; | |
295 | mparam[2] = bparam[2]/step; | |
6c94f330 | 296 | mparam[3] = bparam[3]/step; |
297 | mparam[5] = bparam[5]/step; | |
298 | return bparam[0]/step; | |
7d0f8548 | 299 | |
7d0f8548 | 300 | } |
301 |