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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 | ||
16 | //------------------------------------------------------------------------- | |
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 |
1aedd96e | 21 | // The class is used by AliITStrackerV2 and AliITStrackerSA classes |
22 | // (for the meaning of the track parametrization see AliITStrackV2.h) | |
006b5f7f | 23 | //------------------------------------------------------------------------- |
24 | ||
25 | #include <TMatrixD.h> | |
26 | ||
27 | #include <TMath.h> | |
006b5f7f | 28 | |
29 | #include "AliCluster.h" | |
83d73500 | 30 | #include "AliESDtrack.h" |
006b5f7f | 31 | #include "AliITStrackV2.h" |
32 | ||
1aedd96e | 33 | #define kWARN 5 |
006b5f7f | 34 | |
1aedd96e | 35 | ClassImp(AliITStrackV2) |
8676d691 | 36 | |
22b13da0 | 37 | //____________________________________________________________________________ |
e6ba4672 | 38 | AliITStrackV2::AliITStrackV2():AliKalmanTrack(), |
22b13da0 | 39 | fX(0), |
40 | fAlpha(0), | |
41 | fdEdx(0), | |
42 | fP0(0), | |
43 | fP1(0), | |
44 | fP2(0), | |
45 | fP3(0), | |
46 | fP4(0), | |
47 | fC00(0), | |
48 | fC10(0), | |
49 | fC11(0), | |
50 | fC20(0), | |
51 | fC21(0), | |
52 | fC22(0), | |
53 | fC30(0), | |
54 | fC31(0), | |
55 | fC32(0), | |
56 | fC33(0), | |
57 | fC40(0), | |
58 | fC41(0), | |
59 | fC42(0), | |
60 | fC43(0), | |
83d73500 | 61 | fC44(0), |
babd135a | 62 | fNUsed(0), |
63 | fNSkipped(0), | |
64 | fReconstructed(kFALSE), | |
83d73500 | 65 | fESDtrack(0) |
e6ba4672 | 66 | { |
1aedd96e | 67 | //------------------------------------------------------------------ |
68 | // The default constructor | |
69 | //------------------------------------------------------------------ | |
22b13da0 | 70 | for(Int_t i=0; i<kMaxLayer; i++) fIndex[i]=0; |
71 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; | |
babd135a | 72 | for(Int_t i=0; i<6; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fChi2MIP[i]=0;} |
22b13da0 | 73 | } |
83d73500 | 74 | |
83d73500 | 75 | //____________________________________________________________________________ |
67c3dcbe | 76 | AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) : |
83d73500 | 77 | AliKalmanTrack() { |
78 | //------------------------------------------------------------------ | |
67c3dcbe | 79 | // Conversion ESD track -> ITS track. |
80 | // If c==kTRUE, create the ITS track out of the constrained params. | |
83d73500 | 81 | //------------------------------------------------------------------ |
82 | SetNumberOfClusters(t.GetITSclusters(fIndex)); | |
83 | SetLabel(t.GetLabel()); | |
84 | SetMass(t.GetMass()); | |
85 | ||
86 | fdEdx=t.GetITSsignal(); | |
87 | fAlpha = t.GetAlpha(); | |
88 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); | |
89 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
90 | ||
9b280d80 | 91 | //Conversion of the track parameters |
67c3dcbe | 92 | Double_t x,p[5]; |
93 | if (c) t.GetConstrainedExternalParameters(x,p); | |
94 | else t.GetExternalParameters(x,p); | |
9b280d80 | 95 | fX=x; x=GetConvConst(); |
006b5f7f | 96 | fP0=p[0]; |
97 | fP1=p[1]; | |
98 | fP2=p[2]; | |
99 | fP3=p[3]; | |
100 | fP4=p[4]/x; | |
101 | ||
9b280d80 | 102 | //Conversion of the covariance matrix |
67c3dcbe | 103 | Double_t cv[15]; |
104 | if (c) t.GetConstrainedExternalCovariance(cv); | |
105 | else t.GetExternalCovariance(cv); | |
106 | fC00=cv[0 ]; | |
107 | fC10=cv[1 ]; fC11=cv[2 ]; | |
108 | fC20=cv[3 ]; fC21=cv[4 ]; fC22=cv[5 ]; | |
109 | fC30=cv[6 ]; fC31=cv[7 ]; fC32=cv[8 ]; fC33=cv[9 ]; | |
110 | fC40=cv[10]/x; fC41=cv[11]/x; fC42=cv[12]/x; fC43=cv[13]/x; fC44=cv[14]/x/x; | |
006b5f7f | 111 | |
83d73500 | 112 | if (t.GetStatus()&AliESDtrack::kTIME) { |
113 | StartTimeIntegral(); | |
114 | Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times); | |
115 | SetIntegratedLength(t.GetIntegratedLength()); | |
116 | } | |
117 | fESDtrack=&t; | |
babd135a | 118 | fNUsed = 0; |
119 | fReconstructed = kFALSE; | |
120 | fNSkipped =0; | |
121 | for(Int_t i=0; i<6; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;; fChi2MIP[i]=0;} | |
0aa211b1 | 122 | //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
babd135a | 123 | SetFakeRatio(t.GetITSFakeRatio()); |
006b5f7f | 124 | } |
125 | ||
83d73500 | 126 | void AliITStrackV2::UpdateESDtrack(ULong_t flags) { |
127 | fESDtrack->UpdateTrackParams(this,flags); | |
babd135a | 128 | if (flags == AliESDtrack::kITSin) fESDtrack->SetITSChi2MIP(fChi2MIP); |
83d73500 | 129 | } |
67c3dcbe | 130 | void AliITStrackV2::SetConstrainedESDtrack(Double_t chi2) { |
131 | fESDtrack->SetConstrainedTrackParams(this,chi2); | |
132 | } | |
83d73500 | 133 | |
006b5f7f | 134 | //____________________________________________________________________________ |
135 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { | |
136 | //------------------------------------------------------------------ | |
137 | //Copy constructor | |
138 | //------------------------------------------------------------------ | |
139 | fX=t.fX; | |
140 | fAlpha=t.fAlpha; | |
141 | fdEdx=t.fdEdx; | |
142 | ||
143 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; | |
144 | ||
145 | fC00=t.fC00; | |
146 | fC10=t.fC10; fC11=t.fC11; | |
147 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; | |
148 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; | |
149 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; | |
150 | ||
151 | Int_t n=GetNumberOfClusters(); | |
23efe5f1 | 152 | for (Int_t i=0; i<n; i++) { |
a9a2d814 | 153 | fIndex[i]=t.fIndex[i]; |
154 | if (i<4) fdEdxSample[i]=t.fdEdxSample[i]; | |
23efe5f1 | 155 | } |
83d73500 | 156 | fESDtrack=t.fESDtrack; |
babd135a | 157 | fNUsed = t.fNUsed; |
158 | fReconstructed = t.fReconstructed; | |
159 | fNSkipped = t.fNSkipped; | |
160 | for(Int_t i=0; i<6; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i]; fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i];; fChi2MIP[i]=t.fChi2MIP[i];} | |
006b5f7f | 161 | } |
a9a2d814 | 162 | |
006b5f7f | 163 | //_____________________________________________________________________________ |
164 | Int_t AliITStrackV2::Compare(const TObject *o) const { | |
165 | //----------------------------------------------------------------- | |
166 | // This function compares tracks according to the their curvature | |
167 | //----------------------------------------------------------------- | |
7f6ddf58 | 168 | AliITStrackV2 *t=(AliITStrackV2*)o; |
a9a2d814 | 169 | //Double_t co=TMath::Abs(t->Get1Pt()); |
170 | //Double_t c =TMath::Abs(Get1Pt()); | |
babd135a | 171 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2()*TMath::Sqrt(TMath::Abs(fP4)); |
172 | Double_t c =GetSigmaY2()*GetSigmaZ2()*TMath::Sqrt(TMath::Abs(fP4)); | |
006b5f7f | 173 | if (c>co) return 1; |
174 | else if (c<co) return -1; | |
175 | return 0; | |
176 | } | |
177 | ||
178 | //_____________________________________________________________________________ | |
179 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { | |
180 | //------------------------------------------------------------------------- | |
181 | // This function returns an external representation of the covriance matrix. | |
182 | // (See comments in AliTPCtrack.h about external track representation) | |
183 | //------------------------------------------------------------------------- | |
9b280d80 | 184 | Double_t a=GetConvConst(); |
006b5f7f | 185 | |
186 | cc[0 ]=fC00; | |
187 | cc[1 ]=fC10; cc[2 ]=fC11; | |
188 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; | |
189 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; | |
190 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; | |
191 | } | |
192 | ||
193 | //____________________________________________________________________________ | |
a9a2d814 | 194 | Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) { |
006b5f7f | 195 | //------------------------------------------------------------------ |
196 | //This function propagates a track to the minimal distance from the origin | |
197 | //------------------------------------------------------------------ | |
5b316485 | 198 | //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. |
199 | Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2)); | |
200 | Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf); | |
201 | Double_t xv=(snf - fP2)/fP4 + fX; | |
202 | return PropagateTo(xv,d,x0); | |
006b5f7f | 203 | } |
204 | ||
205 | //____________________________________________________________________________ | |
206 | Int_t AliITStrackV2:: | |
207 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { | |
208 | //------------------------------------------------------------------ | |
209 | //This function returns a track position in the global system | |
210 | //------------------------------------------------------------------ | |
211 | Double_t dx=xk-fX; | |
212 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
a9a2d814 | 213 | if (TMath::Abs(f2) >= 0.9999) { |
7f6ddf58 | 214 | Int_t n=GetNumberOfClusters(); |
215 | if (n>kWARN) | |
8676d691 | 216 | Warning("GetGlobalXYZat","Propagation failed (%d) !\n",n); |
006b5f7f | 217 | return 0; |
218 | } | |
219 | ||
220 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); | |
221 | ||
222 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); | |
223 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
224 | ||
225 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); | |
226 | x = xk*cs - yk*sn; | |
227 | y = xk*sn + yk*cs; | |
228 | z = zk; | |
229 | ||
230 | return 1; | |
231 | } | |
232 | ||
233 | //_____________________________________________________________________________ | |
234 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const | |
235 | { | |
236 | //----------------------------------------------------------------- | |
237 | // This function calculates a predicted chi2 increment. | |
238 | //----------------------------------------------------------------- | |
239 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
240 | r00+=fC00; r01+=fC10; r11+=fC11; | |
babd135a | 241 | // |
006b5f7f | 242 | Double_t det=r00*r11 - r01*r01; |
7f6ddf58 | 243 | if (TMath::Abs(det) < 1.e-30) { |
006b5f7f | 244 | Int_t n=GetNumberOfClusters(); |
7f6ddf58 | 245 | if (n>kWARN) |
8676d691 | 246 | Warning("GetPredictedChi2","Singular matrix (%d) !\n",n); |
006b5f7f | 247 | return 1e10; |
248 | } | |
249 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; | |
33329428 | 250 | |
006b5f7f | 251 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
33329428 | 252 | |
006b5f7f | 253 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; |
254 | } | |
255 | ||
006b5f7f | 256 | //____________________________________________________________________________ |
a9a2d814 | 257 | Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) { |
258 | //------------------------------------------------------------------ | |
259 | //This function corrects the track parameters for crossed material | |
260 | //------------------------------------------------------------------ | |
261 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
262 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
263 | d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); | |
264 | ||
265 | //Multiple scattering****************** | |
266 | if (d!=0) { | |
33329428 | 267 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d); |
268 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33; | |
a9a2d814 | 269 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
270 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); | |
271 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); | |
272 | fC44 += theta2*fP3*fP4*fP3*fP4; | |
273 | } | |
274 | ||
275 | //Energy losses************************ | |
276 | if (x0!=0.) { | |
277 | d*=x0; | |
278 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d; | |
83d73500 | 279 | if (beta2/(1-beta2)>3.5*3.5) |
280 | dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d; | |
a9a2d814 | 281 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); |
282 | } | |
283 | ||
284 | if (!Invariant()) return 0; | |
285 | ||
286 | return 1; | |
287 | } | |
288 | ||
289 | //____________________________________________________________________________ | |
290 | Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { | |
006b5f7f | 291 | //------------------------------------------------------------------ |
292 | //This function propagates a track | |
293 | //------------------------------------------------------------------ | |
294 | Double_t x1=fX, x2=xk, dx=x2-x1; | |
295 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
a9a2d814 | 296 | if (TMath::Abs(f2) >= 0.9999) { |
006b5f7f | 297 | Int_t n=GetNumberOfClusters(); |
7f6ddf58 | 298 | if (n>kWARN) |
8676d691 | 299 | Warning("PropagateTo","Propagation failed !\n",n); |
006b5f7f | 300 | return 0; |
301 | } | |
302 | ||
f29dbb4b | 303 | // old position [SR, GSI, 17.02.2003] |
304 | Double_t oldX = fX, oldY = fP0, oldZ = fP1; | |
305 | ||
006b5f7f | 306 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
307 | ||
308 | fP0 += dx*(f1+f2)/(r1+r2); | |
309 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
310 | fP2 += dx*fP4; | |
311 | ||
312 | //f = F - 1 | |
313 | ||
314 | Double_t f02= dx/(r1*r1*r1); | |
315 | Double_t f04=0.5*dx*dx/(r1*r1*r1); | |
316 | Double_t f12= dx*fP3*f1/(r1*r1*r1); | |
317 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); | |
318 | Double_t f13= dx/r1; | |
319 | Double_t f24= dx; | |
320 | ||
321 | //b = C*ft | |
322 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; | |
323 | Double_t b02=f24*fC40; | |
324 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; | |
325 | Double_t b12=f24*fC41; | |
326 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; | |
327 | Double_t b22=f24*fC42; | |
328 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; | |
329 | Double_t b42=f24*fC44; | |
330 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; | |
331 | Double_t b32=f24*fC43; | |
332 | ||
333 | //a = f*b = f*C*ft | |
334 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; | |
335 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; | |
336 | Double_t a22=f24*b42; | |
337 | ||
338 | //F*C*Ft = C + (b + bt + a) | |
339 | fC00 += b00 + b00 + a00; | |
340 | fC10 += b10 + b01 + a01; | |
341 | fC20 += b20 + b02 + a02; | |
342 | fC30 += b30; | |
343 | fC40 += b40; | |
344 | fC11 += b11 + b11 + a11; | |
345 | fC21 += b21 + b12 + a12; | |
346 | fC31 += b31; | |
347 | fC41 += b41; | |
348 | fC22 += b22 + b22 + a22; | |
349 | fC32 += b32; | |
350 | fC42 += b42; | |
351 | ||
352 | fX=x2; | |
353 | ||
a9a2d814 | 354 | if (!CorrectForMaterial(d,x0)) return 0; |
006b5f7f | 355 | |
f29dbb4b | 356 | // Integrated Time [SR, GSI, 17.02.2003] |
880f41b9 | 357 | if (IsStartedTimeIntegral() && fX>oldX) { |
8676d691 | 358 | Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+ |
359 | (fP1-oldZ)*(fP1-oldZ); | |
f29dbb4b | 360 | AddTimeStep(TMath::Sqrt(l2)); |
361 | } | |
362 | // | |
363 | ||
006b5f7f | 364 | return 1; |
365 | } | |
366 | ||
367 | //____________________________________________________________________________ | |
368 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { | |
369 | //------------------------------------------------------------------ | |
370 | //This function updates track parameters | |
371 | //------------------------------------------------------------------ | |
372 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; | |
373 | Double_t c00=fC00; | |
374 | Double_t c10=fC10, c11=fC11; | |
375 | Double_t c20=fC20, c21=fC21, c22=fC22; | |
376 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; | |
377 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; | |
378 | ||
379 | ||
380 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
381 | r00+=fC00; r01+=fC10; r11+=fC11; | |
382 | Double_t det=r00*r11 - r01*r01; | |
383 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; | |
384 | ||
babd135a | 385 | |
006b5f7f | 386 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
387 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; | |
388 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; | |
389 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; | |
390 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; | |
391 | ||
392 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; | |
babd135a | 393 | Int_t layer = (index & 0xf0000000) >> 28; |
394 | fDy[layer] = dy; | |
395 | fDz[layer] = dz; | |
396 | fSigmaY[layer] = TMath::Sqrt(c->GetSigmaY2()+fC00); | |
397 | fSigmaZ[layer] = TMath::Sqrt(c->GetSigmaZ2()+fC11); | |
398 | ||
006b5f7f | 399 | Double_t sf=fP2 + k20*dy + k21*dz; |
7f6ddf58 | 400 | |
006b5f7f | 401 | fP0 += k00*dy + k01*dz; |
402 | fP1 += k10*dy + k11*dz; | |
403 | fP2 = sf; | |
404 | fP3 += k30*dy + k31*dz; | |
405 | fP4 += k40*dy + k41*dz; | |
406 | ||
407 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; | |
408 | Double_t c12=fC21, c13=fC31, c14=fC41; | |
409 | ||
410 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; | |
411 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; | |
412 | fC40-=k00*c04+k01*c14; | |
413 | ||
414 | fC11-=k10*c01+k11*fC11; | |
415 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; | |
416 | fC41-=k10*c04+k11*c14; | |
417 | ||
418 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; | |
419 | fC42-=k20*c04+k21*c14; | |
420 | ||
421 | fC33-=k30*c03+k31*c13; | |
422 | fC43-=k30*c04+k31*c14; | |
423 | ||
424 | fC44-=k40*c04+k41*c14; | |
425 | ||
426 | if (!Invariant()) { | |
427 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; | |
428 | fC00=c00; | |
429 | fC10=c10; fC11=c11; | |
430 | fC20=c20; fC21=c21; fC22=c22; | |
431 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; | |
432 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; | |
433 | return 0; | |
434 | } | |
435 | ||
67c3dcbe | 436 | if (chi2<0) return 1; |
437 | ||
006b5f7f | 438 | Int_t n=GetNumberOfClusters(); |
439 | fIndex[n]=index; | |
440 | SetNumberOfClusters(n+1); | |
441 | SetChi2(GetChi2()+chi2); | |
442 | ||
443 | return 1; | |
444 | } | |
445 | ||
006b5f7f | 446 | Int_t AliITStrackV2::Invariant() const { |
447 | //------------------------------------------------------------------ | |
448 | // This function is for debugging purpose only | |
449 | //------------------------------------------------------------------ | |
7f6ddf58 | 450 | Int_t n=GetNumberOfClusters(); |
451 | ||
a9a2d814 | 452 | if (TMath::Abs(fP2)>=0.9999){ |
8676d691 | 453 | if (n>kWARN) Warning("Invariant","fP2=%f\n",fP2); |
a9a2d814 | 454 | return 0; |
455 | } | |
456 | if (fC00<=0 || fC00>9.) { | |
8676d691 | 457 | if (n>kWARN) Warning("Invariant","fC00=%f\n",fC00); |
a9a2d814 | 458 | return 0; |
459 | } | |
460 | if (fC11<=0 || fC11>9.) { | |
8676d691 | 461 | if (n>kWARN) Warning("Invariant","fC11=%f\n",fC11); |
a9a2d814 | 462 | return 0; |
463 | } | |
464 | if (fC22<=0 || fC22>1.) { | |
8676d691 | 465 | if (n>kWARN) Warning("Invariant","fC22=%f\n",fC22); |
a9a2d814 | 466 | return 0; |
467 | } | |
468 | if (fC33<=0 || fC33>1.) { | |
8676d691 | 469 | if (n>kWARN) Warning("Invariant","fC33=%f\n",fC33); |
a9a2d814 | 470 | return 0; |
471 | } | |
472 | if (fC44<=0 || fC44>6e-5) { | |
8676d691 | 473 | if (n>kWARN) Warning("Invariant","fC44=%f\n",fC44); |
a9a2d814 | 474 | return 0; |
14825d5a | 475 | } |
14825d5a | 476 | return 1; |
006b5f7f | 477 | } |
478 | ||
479 | //____________________________________________________________________________ | |
a9a2d814 | 480 | Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { |
006b5f7f | 481 | //------------------------------------------------------------------ |
482 | //This function propagates a track | |
483 | //------------------------------------------------------------------ | |
33329428 | 484 | Double_t alpha=fAlpha, x=fX; |
006b5f7f | 485 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
486 | Double_t c00=fC00; | |
487 | Double_t c10=fC10, c11=fC11; | |
488 | Double_t c20=fC20, c21=fC21, c22=fC22; | |
489 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; | |
490 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; | |
491 | ||
33329428 | 492 | if (alp < -TMath::Pi()) alp += 2*TMath::Pi(); |
493 | else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi(); | |
494 | Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha); | |
495 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); | |
006b5f7f | 496 | |
5aa865de | 497 | TMatrixD *tT=0; |
33329428 | 498 | // **** rotation ********************** |
499 | { | |
006b5f7f | 500 | fAlpha = alp; |
33329428 | 501 | fX = x*ca + p0*sa; |
502 | fP0= -x*sa + p0*ca; | |
503 | fP2= sf*ca - cf*sa; | |
504 | ||
5aa865de | 505 | TMatrixD cC(5,5); |
506 | cC(0,0)=c00; | |
507 | cC(1,0)=c10; cC(1,1)=c11; | |
508 | cC(2,0)=c20; cC(2,1)=c21; cC(2,2)=c22; | |
509 | cC(3,0)=c30; cC(3,1)=c31; cC(3,2)=c32; cC(3,3)=c33; | |
510 | cC(4,0)=c40; cC(4,1)=c41; cC(4,2)=c42; cC(4,3)=c43; cC(4,4)=c44; | |
511 | cC(0,1)=cC(1,0); | |
512 | cC(0,2)=cC(2,0); cC(1,2)=cC(2,1); | |
513 | cC(0,3)=cC(3,0); cC(1,3)=cC(3,1); cC(2,3)=cC(3,2); | |
514 | cC(0,4)=cC(4,0); cC(1,4)=cC(4,1); cC(2,4)=cC(4,2); cC(3,4)=cC(4,3); | |
515 | ||
516 | TMatrixD mF(6,5); | |
517 | mF(0,0)=sa; | |
518 | mF(1,0)=ca; | |
519 | mF(2,1)=mF(4,3)=mF(5,4)=1; | |
520 | mF(3,2)=ca + sf/cf*sa; | |
521 | ||
522 | TMatrixD tmp(cC,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, mF)); | |
523 | tT=new TMatrixD(mF,TMatrixD::kMult,tmp); | |
33329428 | 524 | } |
006b5f7f | 525 | |
33329428 | 526 | // **** translation ****************** |
527 | { | |
528 | Double_t dx=xk-fX; | |
006b5f7f | 529 | Double_t f1=fP2, f2=f1 + fP4*dx; |
a9a2d814 | 530 | if (TMath::Abs(f2) >= 0.9999) { |
006b5f7f | 531 | Int_t n=GetNumberOfClusters(); |
7f6ddf58 | 532 | if (n>kWARN) |
8676d691 | 533 | Warning("Propagate","Propagation failed (%d) !\n",n); |
006b5f7f | 534 | return 0; |
535 | } | |
33329428 | 536 | Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2); |
006b5f7f | 537 | |
33329428 | 538 | fX=xk; |
006b5f7f | 539 | fP0 += dx*(f1+f2)/(r1+r2); |
540 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
541 | fP2 += dx*fP4; | |
542 | ||
5aa865de | 543 | TMatrixD mF(5,6); |
544 | mF(0,1)=mF(1,2)=mF(2,3)=mF(3,4)=mF(4,5)=1; | |
545 | mF(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2)); | |
546 | mF(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2)); | |
547 | mF(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1)); | |
548 | mF(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1); | |
549 | mF(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1)); | |
550 | mF(2,5)=dx; | |
551 | mF(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2)); | |
552 | mF(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1))); | |
553 | mF(2,0)=-fP4; | |
554 | ||
555 | TMatrixD tmp(*tT,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, mF)); | |
556 | delete tT; | |
557 | TMatrixD cC(mF,TMatrixD::kMult,tmp); | |
558 | ||
559 | fC00=cC(0,0); | |
560 | fC10=cC(1,0); fC11=cC(1,1); | |
561 | fC20=cC(2,0); fC21=cC(2,1); fC22=cC(2,2); | |
562 | fC30=cC(3,0); fC31=cC(3,1); fC32=cC(3,2); fC33=cC(3,3); | |
563 | fC40=cC(4,0); fC41=cC(4,1); fC42=cC(4,2); fC43=cC(4,3); fC44=cC(4,4); | |
006b5f7f | 564 | |
006b5f7f | 565 | if (!Invariant()) { |
33329428 | 566 | fAlpha=alpha; |
567 | fX=x; | |
006b5f7f | 568 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
569 | fC00=c00; | |
570 | fC10=c10; fC11=c11; | |
571 | fC20=c20; fC21=c21; fC22=c22; | |
572 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; | |
573 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; | |
574 | return 0; | |
575 | } | |
33329428 | 576 | } |
006b5f7f | 577 | |
578 | return 1; | |
579 | } | |
580 | ||
a6a6f799 | 581 | Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const { |
006b5f7f | 582 | //------------------------------------------------------------------ |
a6a6f799 | 583 | // This function calculates the transverse impact parameter |
584 | // with respect to a point with global coordinates (x,y) | |
006b5f7f | 585 | //------------------------------------------------------------------ |
a6a6f799 | 586 | Double_t xt=fX, yt=fP0; |
587 | ||
588 | Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha); | |
589 | Double_t a = x*cs + y*sn; | |
590 | y = -x*sn + y*cs; x=a; | |
591 | xt-=x; yt-=y; | |
592 | ||
593 | sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2); | |
594 | a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt); | |
006b5f7f | 595 | if (fP4<0) a=-a; |
596 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); | |
a9a2d814 | 597 | } |
006b5f7f | 598 | |
babd135a | 599 | Double_t AliITStrackV2::GetZat(Double_t x) const { |
600 | //------------------------------------------------------------------ | |
601 | // This function calculates the z at given x point - in current coordinate system | |
602 | //------------------------------------------------------------------ | |
603 | Double_t x1=fX, x2=x, dx=x2-x1; | |
604 | // | |
605 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
606 | if (TMath::Abs(f2) >= 0.9999) { | |
607 | return 10000000; | |
608 | } | |
609 | ||
610 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); | |
611 | Double_t z = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
612 | return z; | |
613 | } | |
614 | ||
615 | ||
616 | ||
617 | ||
8676d691 | 618 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) { |
a9a2d814 | 619 | //------------------------------------------------------------------ |
620 | //This function improves angular track parameters | |
621 | //------------------------------------------------------------------ | |
8676d691 | 622 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
623 | //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex | |
624 | Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the | |
625 | Double_t zv = xyz[2]; // local frame | |
a9a2d814 | 626 | Double_t dy=fP0-yv, dz=fP1-zv; |
627 | Double_t r2=fX*fX+dy*dy; | |
628 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
629 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
630 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
8676d691 | 631 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
632 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
a9a2d814 | 633 | { |
634 | Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); | |
635 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
636 | sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); | |
8676d691 | 637 | sigma2p += ers[1]*ers[1]/r2; |
a9a2d814 | 638 | sigma2p += 0.25*fC44*fX*fX; |
639 | Double_t eps2p=sigma2p/(fC22+sigma2p); | |
640 | fP0 += fC20/(fC22+sigma2p)*(parp-fP2); | |
641 | fP2 = eps2p*fP2 + (1-eps2p)*parp; | |
642 | fC22 *= eps2p; | |
643 | fC20 *= eps2p; | |
644 | } | |
645 | { | |
646 | Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); | |
647 | Double_t sigma2l=theta2; | |
648 | sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); | |
8676d691 | 649 | sigma2l += ers[2]*ers[2]/r2; |
a9a2d814 | 650 | Double_t eps2l=sigma2l/(fC33+sigma2l); |
651 | fP1 += fC31/(fC33+sigma2l)*(parl-fP3); | |
652 | fP4 += fC43/(fC33+sigma2l)*(parl-fP3); | |
653 | fP3 = eps2l*fP3 + (1-eps2l)*parl; | |
654 | fC33 *= eps2l; fC43 *= eps2l; | |
655 | fC31 *= eps2l; | |
656 | } | |
657 | if (!Invariant()) return 0; | |
658 | return 1; | |
659 | } | |
006b5f7f | 660 | |
a9a2d814 | 661 | /* |
006b5f7f | 662 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
663 | //------------------------------------------------------------------ | |
664 | //This function improves angular track parameters | |
665 | //------------------------------------------------------------------ | |
666 | Double_t dy=fP0-yv, dz=fP1-zv; | |
667 | Double_t r2=fX*fX+dy*dy; | |
668 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
7f6ddf58 | 669 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
006b5f7f | 670 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
a9a2d814 | 671 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
672 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
006b5f7f | 673 | |
674 | Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); | |
675 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
676 | sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); | |
677 | sigma2 += kSigmaYV*kSigmaYV/r2; | |
678 | sigma2 += 0.25*fC44*fX*fX; | |
679 | Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2); | |
680 | if (10*r2*fC44<fC22) { | |
681 | fP2 = eps2*fP2 + (1-eps2)*par; | |
682 | fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps; | |
683 | } | |
684 | ||
685 | par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); | |
686 | sigma2=theta2; | |
687 | sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); | |
688 | sigma2 += kSigmaZV*kSigmaZV/r2; | |
689 | eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2); | |
690 | Double_t tgl=fP3; | |
691 | fP3 = eps2*fP3 + (1-eps2)*par; | |
692 | fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps; | |
693 | ||
694 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); | |
695 | fP4*=eps; | |
696 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; | |
697 | ||
698 | if (!Invariant()) return 0; | |
699 | return 1; | |
700 | } | |
006b5f7f | 701 | */ |
14825d5a | 702 | void AliITStrackV2::ResetCovariance() { |
703 | //------------------------------------------------------------------ | |
704 | //This function makes a track forget its history :) | |
705 | //------------------------------------------------------------------ | |
706 | ||
707 | fC00*=10.; | |
708 | fC10=0.; fC11*=10.; | |
709 | fC20=0.; fC21=0.; fC22*=10.; | |
710 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; | |
711 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; | |
712 | ||
713 | } | |
23efe5f1 | 714 | |
715 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { | |
716 | //----------------------------------------------------------------- | |
a9a2d814 | 717 | // This function calculates dE/dX within the "low" and "up" cuts. |
718 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
23efe5f1 | 719 | //----------------------------------------------------------------- |
23efe5f1 | 720 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 |
c0dd5278 | 721 | |
722 | Int_t i; | |
723 | Int_t nc=0; | |
724 | for (i=0; i<GetNumberOfClusters(); i++) { | |
725 | Int_t idx=GetClusterIndex(i); | |
726 | idx=(idx&0xf0000000)>>28; | |
727 | if (idx>1) nc++; // Take only SSD and SDD | |
728 | } | |
23efe5f1 | 729 | |
a9a2d814 | 730 | Int_t swap;//stupid sorting |
23efe5f1 | 731 | do { |
732 | swap=0; | |
733 | for (i=0; i<nc-1; i++) { | |
734 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; | |
735 | Float_t tmp=fdEdxSample[i]; | |
736 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; | |
737 | swap++; | |
738 | } | |
739 | } while (swap); | |
740 | ||
a9a2d814 | 741 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX |
742 | // values from four ones choose | |
743 | // nu=2 | |
23efe5f1 | 744 | Float_t dedx=0; |
a9a2d814 | 745 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; |
c0dd5278 | 746 | if (nu-nl>0) dedx /= (nu-nl); |
23efe5f1 | 747 | |
23efe5f1 | 748 | SetdEdx(dedx); |
749 | } |