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006b5f7f | 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 | ||
66e811e2 | 16 | /////////////////////////////////////////////////////////////////////////// |
006b5f7f | 17 | // Implementation of the ITS track class |
18 | // | |
19 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch | |
a9a2d814 | 20 | // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch |
66e811e2 | 21 | /////////////////////////////////////////////////////////////////////////// |
006b5f7f | 22 | #include <TMath.h> |
006b5f7f | 23 | |
24 | #include "AliCluster.h" | |
6c94f330 | 25 | #include "AliTracker.h" |
83d73500 | 26 | #include "AliESDtrack.h" |
006b5f7f | 27 | #include "AliITStrackV2.h" |
28 | ||
1aedd96e | 29 | ClassImp(AliITStrackV2) |
8676d691 | 30 | |
e43c066c | 31 | const Int_t kWARN=5; |
32 | ||
22b13da0 | 33 | //____________________________________________________________________________ |
6c94f330 | 34 | AliITStrackV2::AliITStrackV2() : AliKalmanTrack(), |
22b13da0 | 35 | fdEdx(0), |
83d73500 | 36 | fESDtrack(0) |
e43c066c | 37 | { |
ef7253ac | 38 | for(Int_t i=0; i<2*kMaxLayer; i++) fIndex[i]=-1; |
e43c066c | 39 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; |
e43c066c | 40 | } |
41 | ||
83d73500 | 42 | |
83d73500 | 43 | //____________________________________________________________________________ |
67c3dcbe | 44 | AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) : |
6c94f330 | 45 | AliKalmanTrack(), |
46 | fdEdx(t.GetITSsignal()), | |
47 | fESDtrack(&t) | |
48 | { | |
83d73500 | 49 | //------------------------------------------------------------------ |
67c3dcbe | 50 | // Conversion ESD track -> ITS track. |
51 | // If c==kTRUE, create the ITS track out of the constrained params. | |
83d73500 | 52 | //------------------------------------------------------------------ |
6c94f330 | 53 | const AliExternalTrackParam *par=&t; |
54 | if (c) { | |
6c4ef2ed | 55 | par=t.GetConstrainedParam(); |
6c94f330 | 56 | if (!par) throw "AliITStrackV2: conversion failed !\n"; |
57 | } | |
58 | Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance()); | |
59 | ||
60 | //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; | |
61 | ||
83d73500 | 62 | SetLabel(t.GetLabel()); |
63 | SetMass(t.GetMass()); | |
6c94f330 | 64 | SetNumberOfClusters(t.GetITSclusters(fIndex)); |
006b5f7f | 65 | |
83d73500 | 66 | if (t.GetStatus()&AliESDtrack::kTIME) { |
67 | StartTimeIntegral(); | |
68 | Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times); | |
69 | SetIntegratedLength(t.GetIntegratedLength()); | |
70 | } | |
e43c066c | 71 | |
68b8060b | 72 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; |
006b5f7f | 73 | } |
74 | ||
15dd636f | 75 | void AliITStrackV2::UpdateESDtrack(ULong_t flags) const { |
83d73500 | 76 | fESDtrack->UpdateTrackParams(this,flags); |
77 | } | |
78 | ||
006b5f7f | 79 | //____________________________________________________________________________ |
6c94f330 | 80 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : |
81 | AliKalmanTrack(t), | |
82 | fdEdx(t.fdEdx), | |
83 | fESDtrack(t.fESDtrack) | |
84 | { | |
006b5f7f | 85 | //------------------------------------------------------------------ |
86 | //Copy constructor | |
87 | //------------------------------------------------------------------ | |
ef7253ac | 88 | Int_t i; |
ef7253ac | 89 | for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i]; |
6c94f330 | 90 | for (i=0; i<2*kMaxLayer; i++) fIndex[i]=t.fIndex[i]; |
006b5f7f | 91 | } |
a9a2d814 | 92 | |
006b5f7f | 93 | //_____________________________________________________________________________ |
94 | Int_t AliITStrackV2::Compare(const TObject *o) const { | |
95 | //----------------------------------------------------------------- | |
96 | // This function compares tracks according to the their curvature | |
97 | //----------------------------------------------------------------- | |
7f6ddf58 | 98 | AliITStrackV2 *t=(AliITStrackV2*)o; |
a9a2d814 | 99 | //Double_t co=TMath::Abs(t->Get1Pt()); |
100 | //Double_t c =TMath::Abs(Get1Pt()); | |
15dd636f | 101 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); |
102 | Double_t c =GetSigmaY2()*GetSigmaZ2(); | |
006b5f7f | 103 | if (c>co) return 1; |
104 | else if (c<co) return -1; | |
105 | return 0; | |
106 | } | |
107 | ||
006b5f7f | 108 | //____________________________________________________________________________ |
6c94f330 | 109 | Bool_t |
110 | AliITStrackV2::PropagateToVertex(const AliESDVertex *v,Double_t d,Double_t x0) | |
111 | { | |
006b5f7f | 112 | //------------------------------------------------------------------ |
113 | //This function propagates a track to the minimal distance from the origin | |
6c94f330 | 114 | //------------------------------------------------------------------ |
115 | Double_t bz=GetBz(); | |
116 | if (PropagateToDCA(v,bz,kVeryBig)) | |
117 | if (AliExternalTrackParam::CorrectForMaterial(d,x0,GetMass())) return kTRUE; | |
118 | return kFALSE; | |
006b5f7f | 119 | } |
120 | ||
121 | //____________________________________________________________________________ | |
6c94f330 | 122 | Bool_t AliITStrackV2:: |
006b5f7f | 123 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { |
124 | //------------------------------------------------------------------ | |
125 | //This function returns a track position in the global system | |
126 | //------------------------------------------------------------------ | |
6c94f330 | 127 | Double_t r[3]; |
128 | Bool_t rc=GetXYZAt(xk, AliTracker::GetBz(), r); | |
129 | x=r[0]; y=r[1]; z=r[2]; | |
130 | return rc; | |
006b5f7f | 131 | } |
132 | ||
133 | //_____________________________________________________________________________ | |
6c94f330 | 134 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const { |
006b5f7f | 135 | //----------------------------------------------------------------- |
136 | // This function calculates a predicted chi2 increment. | |
137 | //----------------------------------------------------------------- | |
6c94f330 | 138 | Double_t p[2]={c->GetY(), c->GetZ()}; |
139 | Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()}; | |
140 | return AliExternalTrackParam::GetPredictedChi2(p,cov); | |
a9a2d814 | 141 | } |
142 | ||
143 | //____________________________________________________________________________ | |
6c94f330 | 144 | Bool_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { |
006b5f7f | 145 | //------------------------------------------------------------------ |
146 | //This function propagates a track | |
147 | //------------------------------------------------------------------ | |
6c94f330 | 148 | Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ(); |
006b5f7f | 149 | |
6c94f330 | 150 | Double_t bz=GetBz(); |
151 | if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE; | |
152 | if (!AliExternalTrackParam::CorrectForMaterial(d,x0,GetMass())) return kFALSE; | |
006b5f7f | 153 | |
dd44614b | 154 | Double_t x=GetX(), y=GetY(), z=GetZ(); |
6c94f330 | 155 | if (IsStartedTimeIntegral() && x>oldX) { |
156 | Double_t l2 = (x-oldX)*(x-oldX) + (y-oldY)*(y-oldY) + (z-oldZ)*(z-oldZ); | |
f29dbb4b | 157 | AddTimeStep(TMath::Sqrt(l2)); |
158 | } | |
f29dbb4b | 159 | |
6c94f330 | 160 | return kTRUE; |
006b5f7f | 161 | } |
162 | ||
163 | //____________________________________________________________________________ | |
6c94f330 | 164 | Bool_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, Int_t index) |
165 | { | |
006b5f7f | 166 | //------------------------------------------------------------------ |
167 | //This function updates track parameters | |
168 | //------------------------------------------------------------------ | |
6c94f330 | 169 | Double_t p[2]={c->GetY(), c->GetZ()}; |
170 | Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()}; | |
006b5f7f | 171 | |
6c94f330 | 172 | if (!AliExternalTrackParam::Update(p,cov)) return kFALSE; |
006b5f7f | 173 | |
174 | if (!Invariant()) { | |
6c94f330 | 175 | AliWarning("Wrong invariant !"); |
176 | return kFALSE; | |
006b5f7f | 177 | } |
178 | ||
6c94f330 | 179 | if (chi2<0) return kTRUE; |
67c3dcbe | 180 | |
006b5f7f | 181 | Int_t n=GetNumberOfClusters(); |
182 | fIndex[n]=index; | |
183 | SetNumberOfClusters(n+1); | |
184 | SetChi2(GetChi2()+chi2); | |
185 | ||
6c94f330 | 186 | return kTRUE; |
006b5f7f | 187 | } |
188 | ||
6c94f330 | 189 | Bool_t AliITStrackV2::Invariant() const { |
006b5f7f | 190 | //------------------------------------------------------------------ |
191 | // This function is for debugging purpose only | |
192 | //------------------------------------------------------------------ | |
7f6ddf58 | 193 | Int_t n=GetNumberOfClusters(); |
6c94f330 | 194 | |
195 | Double_t sP2=GetParameter()[2]; | |
196 | if (TMath::Abs(sP2) >= kAlmost1){ | |
197 | if (n>kWARN) Warning("Invariant","fP2=%f\n",sP2); | |
198 | return kFALSE; | |
a9a2d814 | 199 | } |
6c94f330 | 200 | Double_t sC00=GetCovariance()[0]; |
201 | if (sC00<=0 || sC00>9.) { | |
202 | if (n>kWARN) Warning("Invariant","fC00=%f\n",sC00); | |
203 | return kFALSE; | |
a9a2d814 | 204 | } |
6c94f330 | 205 | Double_t sC11=GetCovariance()[2]; |
206 | if (sC11<=0 || sC11>9.) { | |
207 | if (n>kWARN) Warning("Invariant","fC11=%f\n",sC11); | |
208 | return kFALSE; | |
a9a2d814 | 209 | } |
6c94f330 | 210 | Double_t sC22=GetCovariance()[5]; |
211 | if (sC22<=0 || sC22>1.) { | |
212 | if (n>kWARN) Warning("Invariant","fC22=%f\n",sC22); | |
213 | return kFALSE; | |
a9a2d814 | 214 | } |
6c94f330 | 215 | Double_t sC33=GetCovariance()[9]; |
216 | if (sC33<=0 || sC33>1.) { | |
217 | if (n>kWARN) Warning("Invariant","fC33=%f\n",sC33); | |
218 | return kFALSE; | |
a9a2d814 | 219 | } |
6c94f330 | 220 | Double_t sC44=GetCovariance()[14]; |
221 | if (sC44<=0 /*|| sC44>6e-5*/) { | |
222 | if (n>kWARN) Warning("Invariant","fC44=%f\n",sC44); | |
223 | return kFALSE; | |
14825d5a | 224 | } |
6c94f330 | 225 | |
226 | return kTRUE; | |
006b5f7f | 227 | } |
228 | ||
229 | //____________________________________________________________________________ | |
6c94f330 | 230 | Bool_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { |
006b5f7f | 231 | //------------------------------------------------------------------ |
232 | //This function propagates a track | |
233 | //------------------------------------------------------------------ | |
6c94f330 | 234 | Double_t bz=GetBz(); |
235 | if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE; | |
006b5f7f | 236 | |
006b5f7f | 237 | if (!Invariant()) { |
6c94f330 | 238 | AliWarning("Wrong invariant !"); |
239 | return kFALSE; | |
791f9a2a | 240 | } |
241 | ||
6c94f330 | 242 | return kTRUE; |
a9a2d814 | 243 | } |
006b5f7f | 244 | |
6c94f330 | 245 | Bool_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) { |
babd135a | 246 | //------------------------------------------------------------------ |
6c94f330 | 247 | //This function improves angular track parameters |
babd135a | 248 | //------------------------------------------------------------------ |
6c94f330 | 249 | Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha()); |
250 | //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex | |
251 | Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the | |
252 | Double_t zv = xyz[2]; // local frame | |
babd135a | 253 | |
6c94f330 | 254 | Double_t dy = Par(0) - yv, dz = Par(1) - zv; |
255 | Double_t r2=GetX()*GetX() + dy*dy; | |
a9a2d814 | 256 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
257 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
258 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
8676d691 | 259 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
260 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
6c94f330 | 261 | |
262 | Double_t cnv=GetBz()*kB2C; | |
a9a2d814 | 263 | { |
6c94f330 | 264 | Double_t dummy = 4/r2 - GetC()*GetC(); |
265 | if (dummy < 0) return kFALSE; | |
266 | Double_t parp = 0.5*(GetC()*GetX() + dy*TMath::Sqrt(dummy)); | |
267 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
268 | sigma2p += Cov(0)/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); | |
269 | sigma2p += ers[1]*ers[1]/r2; | |
270 | sigma2p += 0.25*Cov(14)*cnv*cnv*GetX()*GetX(); | |
00709873 | 271 | Double_t eps2p=sigma2p/(Cov(5) + sigma2p); |
6c94f330 | 272 | Par(0) += Cov(3)/(Cov(5) + sigma2p)*(parp - GetSnp()); |
273 | Par(2) = eps2p*GetSnp() + (1 - eps2p)*parp; | |
274 | Cov(5) *= eps2p; | |
275 | Cov(3) *= eps2p; | |
a9a2d814 | 276 | } |
277 | { | |
6c94f330 | 278 | Double_t parl=0.5*GetC()*dz/TMath::ASin(0.5*GetC()*TMath::Sqrt(r2)); |
279 | Double_t sigma2l=theta2; | |
280 | sigma2l += Cov(2)/r2 + Cov(0)*dy*dy*dz*dz/(r2*r2*r2); | |
281 | sigma2l += ers[2]*ers[2]/r2; | |
282 | Double_t eps2l = sigma2l/(Cov(9) + sigma2l); | |
283 | Par(1) += Cov(7 )/(Cov(9) + sigma2l)*(parl - Par(3)); | |
284 | Par(4) += Cov(13)/(Cov(9) + sigma2l)*(parl - Par(3)); | |
285 | Par(3) = eps2l*Par(3) + (1-eps2l)*parl; | |
286 | Cov(9) *= eps2l; | |
00709873 | 287 | Cov(13)*= eps2l; |
6c94f330 | 288 | Cov(7) *= eps2l; |
a9a2d814 | 289 | } |
6c94f330 | 290 | if (!Invariant()) return kFALSE; |
14825d5a | 291 | |
6c94f330 | 292 | return kTRUE; |
14825d5a | 293 | } |
23efe5f1 | 294 | |
295 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { | |
296 | //----------------------------------------------------------------- | |
a9a2d814 | 297 | // This function calculates dE/dX within the "low" and "up" cuts. |
298 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
23efe5f1 | 299 | //----------------------------------------------------------------- |
23efe5f1 | 300 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 |
c0dd5278 | 301 | |
302 | Int_t i; | |
303 | Int_t nc=0; | |
304 | for (i=0; i<GetNumberOfClusters(); i++) { | |
305 | Int_t idx=GetClusterIndex(i); | |
306 | idx=(idx&0xf0000000)>>28; | |
307 | if (idx>1) nc++; // Take only SSD and SDD | |
308 | } | |
23efe5f1 | 309 | |
a9a2d814 | 310 | Int_t swap;//stupid sorting |
23efe5f1 | 311 | do { |
312 | swap=0; | |
313 | for (i=0; i<nc-1; i++) { | |
314 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; | |
315 | Float_t tmp=fdEdxSample[i]; | |
316 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; | |
317 | swap++; | |
318 | } | |
319 | } while (swap); | |
320 | ||
a9a2d814 | 321 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX |
322 | // values from four ones choose | |
323 | // nu=2 | |
23efe5f1 | 324 | Float_t dedx=0; |
a9a2d814 | 325 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; |
c0dd5278 | 326 | if (nu-nl>0) dedx /= (nu-nl); |
23efe5f1 | 327 | |
23efe5f1 | 328 | SetdEdx(dedx); |
329 | } | |
c7bafca9 | 330 | |
6c94f330 | 331 | Double_t AliITStrackV2::GetBz() const { |
332 | // | |
333 | // returns Bz component of the magnetic field (kG) | |
334 | // | |
335 | if (AliTracker::UniformField()) return AliTracker::GetBz(); | |
336 | Double_t r[3]; GetXYZ(r); | |
337 | return AliTracker::GetBz(r); | |
5773defd | 338 | } |
6c94f330 | 339 |