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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 |
006b5f7f | 21 | //------------------------------------------------------------------------- |
006b5f7f | 22 | #include <TMath.h> |
006b5f7f | 23 | |
24 | #include "AliCluster.h" | |
83d73500 | 25 | #include "AliESDtrack.h" |
006b5f7f | 26 | #include "AliITStrackV2.h" |
27 | ||
1aedd96e | 28 | ClassImp(AliITStrackV2) |
8676d691 | 29 | |
e43c066c | 30 | const Int_t kWARN=5; |
31 | ||
22b13da0 | 32 | //____________________________________________________________________________ |
e6ba4672 | 33 | AliITStrackV2::AliITStrackV2():AliKalmanTrack(), |
22b13da0 | 34 | fX(0), |
35 | fAlpha(0), | |
36 | fdEdx(0), | |
37 | fP0(0), | |
38 | fP1(0), | |
39 | fP2(0), | |
40 | fP3(0), | |
41 | fP4(0), | |
42 | fC00(0), | |
43 | fC10(0), | |
44 | fC11(0), | |
45 | fC20(0), | |
46 | fC21(0), | |
47 | fC22(0), | |
48 | fC30(0), | |
49 | fC31(0), | |
50 | fC32(0), | |
51 | fC33(0), | |
52 | fC40(0), | |
53 | fC41(0), | |
54 | fC42(0), | |
55 | fC43(0), | |
83d73500 | 56 | fC44(0), |
57 | fESDtrack(0) | |
e43c066c | 58 | { |
15dd636f | 59 | for(Int_t i=0; i<kMaxLayer; i++) fIndex[i]=0; |
e43c066c | 60 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; |
e43c066c | 61 | } |
62 | ||
83d73500 | 63 | |
83d73500 | 64 | //____________________________________________________________________________ |
67c3dcbe | 65 | AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) : |
83d73500 | 66 | AliKalmanTrack() { |
67 | //------------------------------------------------------------------ | |
67c3dcbe | 68 | // Conversion ESD track -> ITS track. |
69 | // If c==kTRUE, create the ITS track out of the constrained params. | |
83d73500 | 70 | //------------------------------------------------------------------ |
71 | SetNumberOfClusters(t.GetITSclusters(fIndex)); | |
72 | SetLabel(t.GetLabel()); | |
73 | SetMass(t.GetMass()); | |
e43c066c | 74 | // |
75 | // | |
83d73500 | 76 | |
77 | fdEdx=t.GetITSsignal(); | |
78 | fAlpha = t.GetAlpha(); | |
79 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); | |
80 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
81 | ||
9b280d80 | 82 | //Conversion of the track parameters |
67c3dcbe | 83 | Double_t x,p[5]; |
84 | if (c) t.GetConstrainedExternalParameters(x,p); | |
85 | else t.GetExternalParameters(x,p); | |
9b280d80 | 86 | fX=x; x=GetConvConst(); |
006b5f7f | 87 | fP0=p[0]; |
88 | fP1=p[1]; | |
89 | fP2=p[2]; | |
90 | fP3=p[3]; | |
91 | fP4=p[4]/x; | |
92 | ||
9b280d80 | 93 | //Conversion of the covariance matrix |
67c3dcbe | 94 | Double_t cv[15]; |
95 | if (c) t.GetConstrainedExternalCovariance(cv); | |
96 | else t.GetExternalCovariance(cv); | |
97 | fC00=cv[0 ]; | |
98 | fC10=cv[1 ]; fC11=cv[2 ]; | |
99 | fC20=cv[3 ]; fC21=cv[4 ]; fC22=cv[5 ]; | |
100 | fC30=cv[6 ]; fC31=cv[7 ]; fC32=cv[8 ]; fC33=cv[9 ]; | |
101 | fC40=cv[10]/x; fC41=cv[11]/x; fC42=cv[12]/x; fC43=cv[13]/x; fC44=cv[14]/x/x; | |
006b5f7f | 102 | |
83d73500 | 103 | if (t.GetStatus()&AliESDtrack::kTIME) { |
104 | StartTimeIntegral(); | |
105 | Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times); | |
106 | SetIntegratedLength(t.GetIntegratedLength()); | |
107 | } | |
108 | fESDtrack=&t; | |
e43c066c | 109 | |
15dd636f | 110 | if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
006b5f7f | 111 | } |
112 | ||
15dd636f | 113 | void AliITStrackV2::UpdateESDtrack(ULong_t flags) const { |
83d73500 | 114 | fESDtrack->UpdateTrackParams(this,flags); |
115 | } | |
15dd636f | 116 | void AliITStrackV2::SetConstrainedESDtrack(Double_t chi2) const { |
67c3dcbe | 117 | fESDtrack->SetConstrainedTrackParams(this,chi2); |
118 | } | |
83d73500 | 119 | |
006b5f7f | 120 | //____________________________________________________________________________ |
121 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { | |
122 | //------------------------------------------------------------------ | |
123 | //Copy constructor | |
124 | //------------------------------------------------------------------ | |
125 | fX=t.fX; | |
126 | fAlpha=t.fAlpha; | |
127 | fdEdx=t.fdEdx; | |
128 | ||
129 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; | |
130 | ||
131 | fC00=t.fC00; | |
132 | fC10=t.fC10; fC11=t.fC11; | |
133 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; | |
134 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; | |
135 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; | |
136 | ||
137 | Int_t n=GetNumberOfClusters(); | |
23efe5f1 | 138 | for (Int_t i=0; i<n; i++) { |
e43c066c | 139 | fIndex[i]=t.fIndex[i]; |
140 | if (i<4) fdEdxSample[i]=t.fdEdxSample[i]; | |
23efe5f1 | 141 | } |
83d73500 | 142 | fESDtrack=t.fESDtrack; |
006b5f7f | 143 | } |
a9a2d814 | 144 | |
006b5f7f | 145 | //_____________________________________________________________________________ |
146 | Int_t AliITStrackV2::Compare(const TObject *o) const { | |
147 | //----------------------------------------------------------------- | |
148 | // This function compares tracks according to the their curvature | |
149 | //----------------------------------------------------------------- | |
7f6ddf58 | 150 | AliITStrackV2 *t=(AliITStrackV2*)o; |
a9a2d814 | 151 | //Double_t co=TMath::Abs(t->Get1Pt()); |
152 | //Double_t c =TMath::Abs(Get1Pt()); | |
15dd636f | 153 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); |
154 | Double_t c =GetSigmaY2()*GetSigmaZ2(); | |
006b5f7f | 155 | if (c>co) return 1; |
156 | else if (c<co) return -1; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | //_____________________________________________________________________________ | |
161 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { | |
162 | //------------------------------------------------------------------------- | |
163 | // This function returns an external representation of the covriance matrix. | |
164 | // (See comments in AliTPCtrack.h about external track representation) | |
165 | //------------------------------------------------------------------------- | |
9b280d80 | 166 | Double_t a=GetConvConst(); |
006b5f7f | 167 | |
168 | cc[0 ]=fC00; | |
169 | cc[1 ]=fC10; cc[2 ]=fC11; | |
170 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; | |
171 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; | |
172 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; | |
173 | } | |
174 | ||
175 | //____________________________________________________________________________ | |
a9a2d814 | 176 | Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) { |
006b5f7f | 177 | //------------------------------------------------------------------ |
178 | //This function propagates a track to the minimal distance from the origin | |
179 | //------------------------------------------------------------------ | |
5b316485 | 180 | //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. |
181 | Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2)); | |
182 | Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf); | |
183 | Double_t xv=(snf - fP2)/fP4 + fX; | |
184 | return PropagateTo(xv,d,x0); | |
006b5f7f | 185 | } |
186 | ||
187 | //____________________________________________________________________________ | |
188 | Int_t AliITStrackV2:: | |
189 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { | |
190 | //------------------------------------------------------------------ | |
191 | //This function returns a track position in the global system | |
192 | //------------------------------------------------------------------ | |
193 | Double_t dx=xk-fX; | |
194 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
a9a2d814 | 195 | if (TMath::Abs(f2) >= 0.9999) { |
7f6ddf58 | 196 | Int_t n=GetNumberOfClusters(); |
197 | if (n>kWARN) | |
8676d691 | 198 | Warning("GetGlobalXYZat","Propagation failed (%d) !\n",n); |
006b5f7f | 199 | return 0; |
200 | } | |
201 | ||
202 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); | |
203 | ||
204 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); | |
205 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
206 | ||
207 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); | |
208 | x = xk*cs - yk*sn; | |
209 | y = xk*sn + yk*cs; | |
210 | z = zk; | |
211 | ||
212 | return 1; | |
213 | } | |
214 | ||
215 | //_____________________________________________________________________________ | |
216 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const | |
217 | { | |
218 | //----------------------------------------------------------------- | |
219 | // This function calculates a predicted chi2 increment. | |
220 | //----------------------------------------------------------------- | |
221 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
222 | r00+=fC00; r01+=fC10; r11+=fC11; | |
babd135a | 223 | // |
006b5f7f | 224 | Double_t det=r00*r11 - r01*r01; |
7f6ddf58 | 225 | if (TMath::Abs(det) < 1.e-30) { |
006b5f7f | 226 | Int_t n=GetNumberOfClusters(); |
7f6ddf58 | 227 | if (n>kWARN) |
8676d691 | 228 | Warning("GetPredictedChi2","Singular matrix (%d) !\n",n); |
006b5f7f | 229 | return 1e10; |
230 | } | |
231 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; | |
33329428 | 232 | |
006b5f7f | 233 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
33329428 | 234 | |
006b5f7f | 235 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; |
236 | } | |
237 | ||
006b5f7f | 238 | //____________________________________________________________________________ |
a9a2d814 | 239 | Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) { |
240 | //------------------------------------------------------------------ | |
241 | //This function corrects the track parameters for crossed material | |
242 | //------------------------------------------------------------------ | |
e43c066c | 243 | Double_t p2=(1.+ fP3*fP3)/(Get1Pt()*Get1Pt()); |
15dd636f | 244 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
a9a2d814 | 245 | d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
246 | ||
247 | //Multiple scattering****************** | |
248 | if (d!=0) { | |
33329428 | 249 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d); |
250 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33; | |
a9a2d814 | 251 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
252 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); | |
253 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); | |
254 | fC44 += theta2*fP3*fP4*fP3*fP4; | |
255 | } | |
256 | ||
257 | //Energy losses************************ | |
258 | if (x0!=0.) { | |
259 | d*=x0; | |
15dd636f | 260 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d; |
261 | if (beta2/(1-beta2)>3.5*3.5) | |
83d73500 | 262 | dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d; |
15dd636f | 263 | |
264 | fP4*=(1.- TMath::Sqrt(p2+GetMass()*GetMass())/p2*dE); | |
a9a2d814 | 265 | } |
266 | ||
267 | if (!Invariant()) return 0; | |
268 | ||
269 | return 1; | |
270 | } | |
271 | ||
272 | //____________________________________________________________________________ | |
273 | Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { | |
006b5f7f | 274 | //------------------------------------------------------------------ |
275 | //This function propagates a track | |
276 | //------------------------------------------------------------------ | |
277 | Double_t x1=fX, x2=xk, dx=x2-x1; | |
278 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
a9a2d814 | 279 | if (TMath::Abs(f2) >= 0.9999) { |
006b5f7f | 280 | Int_t n=GetNumberOfClusters(); |
7f6ddf58 | 281 | if (n>kWARN) |
8676d691 | 282 | Warning("PropagateTo","Propagation failed !\n",n); |
006b5f7f | 283 | return 0; |
284 | } | |
285 | ||
f29dbb4b | 286 | // old position [SR, GSI, 17.02.2003] |
287 | Double_t oldX = fX, oldY = fP0, oldZ = fP1; | |
288 | ||
006b5f7f | 289 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
290 | ||
291 | fP0 += dx*(f1+f2)/(r1+r2); | |
292 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
293 | fP2 += dx*fP4; | |
294 | ||
295 | //f = F - 1 | |
296 | ||
297 | Double_t f02= dx/(r1*r1*r1); | |
298 | Double_t f04=0.5*dx*dx/(r1*r1*r1); | |
299 | Double_t f12= dx*fP3*f1/(r1*r1*r1); | |
300 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); | |
301 | Double_t f13= dx/r1; | |
302 | Double_t f24= dx; | |
303 | ||
304 | //b = C*ft | |
305 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; | |
306 | Double_t b02=f24*fC40; | |
307 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; | |
308 | Double_t b12=f24*fC41; | |
309 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; | |
310 | Double_t b22=f24*fC42; | |
311 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; | |
312 | Double_t b42=f24*fC44; | |
313 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; | |
314 | Double_t b32=f24*fC43; | |
315 | ||
316 | //a = f*b = f*C*ft | |
317 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; | |
318 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; | |
319 | Double_t a22=f24*b42; | |
320 | ||
321 | //F*C*Ft = C + (b + bt + a) | |
322 | fC00 += b00 + b00 + a00; | |
323 | fC10 += b10 + b01 + a01; | |
324 | fC20 += b20 + b02 + a02; | |
325 | fC30 += b30; | |
326 | fC40 += b40; | |
327 | fC11 += b11 + b11 + a11; | |
328 | fC21 += b21 + b12 + a12; | |
329 | fC31 += b31; | |
330 | fC41 += b41; | |
331 | fC22 += b22 + b22 + a22; | |
332 | fC32 += b32; | |
333 | fC42 += b42; | |
334 | ||
335 | fX=x2; | |
336 | ||
a9a2d814 | 337 | if (!CorrectForMaterial(d,x0)) return 0; |
006b5f7f | 338 | |
f29dbb4b | 339 | // Integrated Time [SR, GSI, 17.02.2003] |
880f41b9 | 340 | if (IsStartedTimeIntegral() && fX>oldX) { |
8676d691 | 341 | Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+ |
342 | (fP1-oldZ)*(fP1-oldZ); | |
f29dbb4b | 343 | AddTimeStep(TMath::Sqrt(l2)); |
344 | } | |
345 | // | |
346 | ||
006b5f7f | 347 | return 1; |
348 | } | |
349 | ||
350 | //____________________________________________________________________________ | |
351 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { | |
352 | //------------------------------------------------------------------ | |
353 | //This function updates track parameters | |
354 | //------------------------------------------------------------------ | |
355 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; | |
356 | Double_t c00=fC00; | |
357 | Double_t c10=fC10, c11=fC11; | |
358 | Double_t c20=fC20, c21=fC21, c22=fC22; | |
359 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; | |
360 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; | |
361 | ||
362 | ||
363 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
364 | r00+=fC00; r01+=fC10; r11+=fC11; | |
365 | Double_t det=r00*r11 - r01*r01; | |
366 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; | |
367 | ||
babd135a | 368 | |
006b5f7f | 369 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
370 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; | |
371 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; | |
372 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; | |
373 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; | |
374 | ||
375 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; | |
376 | Double_t sf=fP2 + k20*dy + k21*dz; | |
7f6ddf58 | 377 | |
006b5f7f | 378 | fP0 += k00*dy + k01*dz; |
379 | fP1 += k10*dy + k11*dz; | |
380 | fP2 = sf; | |
381 | fP3 += k30*dy + k31*dz; | |
382 | fP4 += k40*dy + k41*dz; | |
383 | ||
384 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; | |
385 | Double_t c12=fC21, c13=fC31, c14=fC41; | |
386 | ||
387 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; | |
388 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; | |
389 | fC40-=k00*c04+k01*c14; | |
390 | ||
391 | fC11-=k10*c01+k11*fC11; | |
392 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; | |
393 | fC41-=k10*c04+k11*c14; | |
394 | ||
395 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; | |
396 | fC42-=k20*c04+k21*c14; | |
397 | ||
398 | fC33-=k30*c03+k31*c13; | |
399 | fC43-=k30*c04+k31*c14; | |
400 | ||
401 | fC44-=k40*c04+k41*c14; | |
402 | ||
403 | if (!Invariant()) { | |
404 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; | |
405 | fC00=c00; | |
406 | fC10=c10; fC11=c11; | |
407 | fC20=c20; fC21=c21; fC22=c22; | |
408 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; | |
409 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; | |
410 | return 0; | |
411 | } | |
412 | ||
67c3dcbe | 413 | if (chi2<0) return 1; |
414 | ||
006b5f7f | 415 | Int_t n=GetNumberOfClusters(); |
416 | fIndex[n]=index; | |
417 | SetNumberOfClusters(n+1); | |
418 | SetChi2(GetChi2()+chi2); | |
419 | ||
420 | return 1; | |
421 | } | |
422 | ||
006b5f7f | 423 | Int_t AliITStrackV2::Invariant() const { |
424 | //------------------------------------------------------------------ | |
425 | // This function is for debugging purpose only | |
426 | //------------------------------------------------------------------ | |
7f6ddf58 | 427 | Int_t n=GetNumberOfClusters(); |
428 | ||
a9a2d814 | 429 | if (TMath::Abs(fP2)>=0.9999){ |
8676d691 | 430 | if (n>kWARN) Warning("Invariant","fP2=%f\n",fP2); |
a9a2d814 | 431 | return 0; |
432 | } | |
433 | if (fC00<=0 || fC00>9.) { | |
8676d691 | 434 | if (n>kWARN) Warning("Invariant","fC00=%f\n",fC00); |
a9a2d814 | 435 | return 0; |
436 | } | |
437 | if (fC11<=0 || fC11>9.) { | |
8676d691 | 438 | if (n>kWARN) Warning("Invariant","fC11=%f\n",fC11); |
a9a2d814 | 439 | return 0; |
440 | } | |
441 | if (fC22<=0 || fC22>1.) { | |
8676d691 | 442 | if (n>kWARN) Warning("Invariant","fC22=%f\n",fC22); |
a9a2d814 | 443 | return 0; |
444 | } | |
445 | if (fC33<=0 || fC33>1.) { | |
8676d691 | 446 | if (n>kWARN) Warning("Invariant","fC33=%f\n",fC33); |
a9a2d814 | 447 | return 0; |
448 | } | |
449 | if (fC44<=0 || fC44>6e-5) { | |
8676d691 | 450 | if (n>kWARN) Warning("Invariant","fC44=%f\n",fC44); |
a9a2d814 | 451 | return 0; |
14825d5a | 452 | } |
14825d5a | 453 | return 1; |
006b5f7f | 454 | } |
455 | ||
456 | //____________________________________________________________________________ | |
a9a2d814 | 457 | Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { |
006b5f7f | 458 | //------------------------------------------------------------------ |
459 | //This function propagates a track | |
460 | //------------------------------------------------------------------ | |
33329428 | 461 | Double_t alpha=fAlpha, x=fX; |
006b5f7f | 462 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
463 | Double_t c00=fC00; | |
464 | Double_t c10=fC10, c11=fC11; | |
465 | Double_t c20=fC20, c21=fC21, c22=fC22; | |
466 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; | |
467 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; | |
468 | ||
33329428 | 469 | if (alp < -TMath::Pi()) alp += 2*TMath::Pi(); |
470 | else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi(); | |
471 | Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha); | |
472 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); | |
006b5f7f | 473 | |
33329428 | 474 | // **** rotation ********************** |
475 | { | |
006b5f7f | 476 | fAlpha = alp; |
33329428 | 477 | fX = x*ca + p0*sa; |
478 | fP0= -x*sa + p0*ca; | |
479 | fP2= sf*ca - cf*sa; | |
480 | ||
c219fd63 | 481 | Double_t rr=(ca+sf/cf*sa); |
482 | ||
483 | fC00 *= (ca*ca); | |
484 | fC10 *= ca; | |
485 | fC20 *= ca*rr; | |
486 | fC30 *= ca; | |
487 | fC40 *= ca; | |
488 | //fC11 = fC11; | |
489 | fC21 *= rr; | |
490 | //fC31 = fC31; | |
491 | //fC41 = fC41; | |
492 | fC22 *= rr*rr; | |
493 | fC32 *= rr; | |
494 | fC42 *= rr; | |
495 | //fC33=fC33; | |
496 | //fC43=fC43; | |
497 | //fC44=fC44; | |
498 | ||
33329428 | 499 | } |
006b5f7f | 500 | |
33329428 | 501 | // **** translation ****************** |
502 | { | |
503 | Double_t dx=xk-fX; | |
006b5f7f | 504 | Double_t f1=fP2, f2=f1 + fP4*dx; |
a9a2d814 | 505 | if (TMath::Abs(f2) >= 0.9999) { |
006b5f7f | 506 | Int_t n=GetNumberOfClusters(); |
7f6ddf58 | 507 | if (n>kWARN) |
8676d691 | 508 | Warning("Propagate","Propagation failed (%d) !\n",n); |
006b5f7f | 509 | return 0; |
510 | } | |
33329428 | 511 | Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2); |
006b5f7f | 512 | |
33329428 | 513 | fX=xk; |
006b5f7f | 514 | fP0 += dx*(f1+f2)/(r1+r2); |
515 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
516 | fP2 += dx*fP4; | |
517 | ||
c219fd63 | 518 | //f = F - 1 |
519 | ||
520 | Double_t f02= dx/(r1*r1*r1); | |
521 | Double_t f04=0.5*dx*dx/(r1*r1*r1); | |
522 | Double_t f12= dx*fP3*f1/(r1*r1*r1); | |
523 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); | |
524 | Double_t f13= dx/r1; | |
525 | Double_t f24= dx; | |
526 | ||
527 | //b = C*ft | |
528 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; | |
529 | Double_t b02=f24*fC40; | |
530 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; | |
531 | Double_t b12=f24*fC41; | |
532 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; | |
533 | Double_t b22=f24*fC42; | |
534 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; | |
535 | Double_t b42=f24*fC44; | |
536 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; | |
537 | Double_t b32=f24*fC43; | |
538 | ||
539 | //a = f*b = f*C*ft | |
540 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; | |
541 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; | |
542 | Double_t a22=f24*b42; | |
543 | ||
544 | //F*C*Ft = C + (b + bt + a) | |
545 | fC00 += b00 + b00 + a00; | |
546 | fC10 += b10 + b01 + a01; | |
547 | fC20 += b20 + b02 + a02; | |
548 | fC30 += b30; | |
549 | fC40 += b40; | |
550 | fC11 += b11 + b11 + a11; | |
551 | fC21 += b21 + b12 + a12; | |
552 | fC31 += b31; | |
553 | fC41 += b41; | |
554 | fC22 += b22 + b22 + a22; | |
555 | fC32 += b32; | |
556 | fC42 += b42; | |
006b5f7f | 557 | |
006b5f7f | 558 | if (!Invariant()) { |
33329428 | 559 | fAlpha=alpha; |
560 | fX=x; | |
006b5f7f | 561 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
562 | fC00=c00; | |
563 | fC10=c10; fC11=c11; | |
564 | fC20=c20; fC21=c21; fC22=c22; | |
565 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; | |
566 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; | |
567 | return 0; | |
568 | } | |
33329428 | 569 | } |
006b5f7f | 570 | |
571 | return 1; | |
572 | } | |
573 | ||
c219fd63 | 574 | |
a6a6f799 | 575 | Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const { |
006b5f7f | 576 | //------------------------------------------------------------------ |
a6a6f799 | 577 | // This function calculates the transverse impact parameter |
578 | // with respect to a point with global coordinates (x,y) | |
006b5f7f | 579 | //------------------------------------------------------------------ |
a6a6f799 | 580 | Double_t xt=fX, yt=fP0; |
581 | ||
582 | Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha); | |
583 | Double_t a = x*cs + y*sn; | |
584 | y = -x*sn + y*cs; x=a; | |
585 | xt-=x; yt-=y; | |
586 | ||
587 | sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2); | |
588 | a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt); | |
006b5f7f | 589 | if (fP4<0) a=-a; |
590 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); | |
a9a2d814 | 591 | } |
006b5f7f | 592 | |
babd135a | 593 | Double_t AliITStrackV2::GetZat(Double_t x) const { |
594 | //------------------------------------------------------------------ | |
595 | // This function calculates the z at given x point - in current coordinate system | |
596 | //------------------------------------------------------------------ | |
597 | Double_t x1=fX, x2=x, dx=x2-x1; | |
598 | // | |
599 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
600 | if (TMath::Abs(f2) >= 0.9999) { | |
601 | return 10000000; | |
602 | } | |
babd135a | 603 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
604 | Double_t z = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
605 | return z; | |
606 | } | |
607 | ||
608 | ||
609 | ||
610 | ||
8676d691 | 611 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) { |
a9a2d814 | 612 | //------------------------------------------------------------------ |
613 | //This function improves angular track parameters | |
614 | //------------------------------------------------------------------ | |
8676d691 | 615 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
616 | //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex | |
617 | Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the | |
618 | Double_t zv = xyz[2]; // local frame | |
a9a2d814 | 619 | Double_t dy=fP0-yv, dz=fP1-zv; |
620 | Double_t r2=fX*fX+dy*dy; | |
621 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
622 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
623 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
8676d691 | 624 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
625 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
a9a2d814 | 626 | { |
627 | Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); | |
628 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
629 | sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); | |
8676d691 | 630 | sigma2p += ers[1]*ers[1]/r2; |
a9a2d814 | 631 | sigma2p += 0.25*fC44*fX*fX; |
632 | Double_t eps2p=sigma2p/(fC22+sigma2p); | |
633 | fP0 += fC20/(fC22+sigma2p)*(parp-fP2); | |
634 | fP2 = eps2p*fP2 + (1-eps2p)*parp; | |
635 | fC22 *= eps2p; | |
636 | fC20 *= eps2p; | |
637 | } | |
638 | { | |
639 | Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); | |
640 | Double_t sigma2l=theta2; | |
641 | sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); | |
8676d691 | 642 | sigma2l += ers[2]*ers[2]/r2; |
a9a2d814 | 643 | Double_t eps2l=sigma2l/(fC33+sigma2l); |
644 | fP1 += fC31/(fC33+sigma2l)*(parl-fP3); | |
645 | fP4 += fC43/(fC33+sigma2l)*(parl-fP3); | |
646 | fP3 = eps2l*fP3 + (1-eps2l)*parl; | |
647 | fC33 *= eps2l; fC43 *= eps2l; | |
648 | fC31 *= eps2l; | |
649 | } | |
650 | if (!Invariant()) return 0; | |
651 | return 1; | |
652 | } | |
006b5f7f | 653 | |
14825d5a | 654 | void AliITStrackV2::ResetCovariance() { |
655 | //------------------------------------------------------------------ | |
656 | //This function makes a track forget its history :) | |
657 | //------------------------------------------------------------------ | |
658 | ||
659 | fC00*=10.; | |
660 | fC10=0.; fC11*=10.; | |
661 | fC20=0.; fC21=0.; fC22*=10.; | |
662 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; | |
663 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; | |
664 | ||
665 | } | |
23efe5f1 | 666 | |
667 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { | |
668 | //----------------------------------------------------------------- | |
a9a2d814 | 669 | // This function calculates dE/dX within the "low" and "up" cuts. |
670 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
23efe5f1 | 671 | //----------------------------------------------------------------- |
23efe5f1 | 672 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 |
c0dd5278 | 673 | |
674 | Int_t i; | |
675 | Int_t nc=0; | |
676 | for (i=0; i<GetNumberOfClusters(); i++) { | |
677 | Int_t idx=GetClusterIndex(i); | |
678 | idx=(idx&0xf0000000)>>28; | |
679 | if (idx>1) nc++; // Take only SSD and SDD | |
680 | } | |
23efe5f1 | 681 | |
a9a2d814 | 682 | Int_t swap;//stupid sorting |
23efe5f1 | 683 | do { |
684 | swap=0; | |
685 | for (i=0; i<nc-1; i++) { | |
686 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; | |
687 | Float_t tmp=fdEdxSample[i]; | |
688 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; | |
689 | swap++; | |
690 | } | |
691 | } while (swap); | |
692 | ||
a9a2d814 | 693 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX |
694 | // values from four ones choose | |
695 | // nu=2 | |
23efe5f1 | 696 | Float_t dedx=0; |
a9a2d814 | 697 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; |
c0dd5278 | 698 | if (nu-nl>0) dedx /= (nu-nl); |
23efe5f1 | 699 | |
23efe5f1 | 700 | SetdEdx(dedx); |
701 | } |