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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 | |
20 | // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
21 | //------------------------------------------------------------------------- | |
22 | ||
23 | #include <TMatrixD.h> | |
24 | ||
25 | #include <TMath.h> | |
26 | #include <Riostream.h> | |
27 | ||
28 | #include "AliCluster.h" | |
29 | #include "AliTPCtrack.h" | |
30 | #include "AliITStrackV2.h" | |
31 | ||
32 | ClassImp(AliITStrackV2) | |
33 | ||
34 | const Int_t kWARN=5; | |
35 | Double_t AliITStrackV2::fSigmaYV = 0.005; | |
36 | Double_t AliITStrackV2::fSigmaZV = 0.01; | |
37 | //____________________________________________________________________________ | |
38 | AliITStrackV2::AliITStrackV2():AliKalmanTrack(), | |
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), | |
61 | fC44(0) | |
62 | { | |
63 | for(Int_t i=0; i<kMaxLayer; i++) fIndex[i]=0; | |
64 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; | |
65 | } | |
66 | //____________________________________________________________________________ | |
67 | AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) : | |
68 | AliKalmanTrack(t) { | |
69 | //------------------------------------------------------------------ | |
70 | //Conversion TPC track -> ITS track | |
71 | //------------------------------------------------------------------ | |
72 | SetChi2(0.); | |
73 | SetNumberOfClusters(0); | |
74 | ||
75 | fdEdx = t.GetdEdx(); | |
76 | SetMass(t.GetMass()); | |
77 | ||
78 | fAlpha = t.GetAlpha(); | |
79 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); | |
80 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
81 | ||
82 | //Conversion of the track parameters | |
83 | Double_t x,p[5]; t.GetExternalParameters(x,p); | |
84 | fX=x; x=GetConvConst(); | |
85 | fP0=p[0]; | |
86 | fP1=p[1]; | |
87 | fP2=p[2]; | |
88 | fP3=p[3]; | |
89 | fP4=p[4]/x; | |
90 | ||
91 | //Conversion of the covariance matrix | |
92 | Double_t c[15]; t.GetExternalCovariance(c); | |
93 | ||
94 | fC00=c[0 ]; | |
95 | fC10=c[1 ]; fC11=c[2 ]; | |
96 | fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ]; | |
97 | fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ]; | |
98 | fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x; | |
99 | ||
100 | if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; | |
101 | ||
102 | } | |
103 | ||
104 | //____________________________________________________________________________ | |
105 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { | |
106 | //------------------------------------------------------------------ | |
107 | //Copy constructor | |
108 | //------------------------------------------------------------------ | |
109 | fX=t.fX; | |
110 | fAlpha=t.fAlpha; | |
111 | fdEdx=t.fdEdx; | |
112 | ||
113 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; | |
114 | ||
115 | fC00=t.fC00; | |
116 | fC10=t.fC10; fC11=t.fC11; | |
117 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; | |
118 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; | |
119 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; | |
120 | ||
121 | Int_t n=GetNumberOfClusters(); | |
122 | for (Int_t i=0; i<n; i++) { | |
123 | fIndex[i]=t.fIndex[i]; | |
124 | if (i<4) fdEdxSample[i]=t.fdEdxSample[i]; | |
125 | } | |
126 | } | |
127 | ||
128 | //_____________________________________________________________________________ | |
129 | Int_t AliITStrackV2::Compare(const TObject *o) const { | |
130 | //----------------------------------------------------------------- | |
131 | // This function compares tracks according to the their curvature | |
132 | //----------------------------------------------------------------- | |
133 | AliITStrackV2 *t=(AliITStrackV2*)o; | |
134 | //Double_t co=TMath::Abs(t->Get1Pt()); | |
135 | //Double_t c =TMath::Abs(Get1Pt()); | |
136 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); | |
137 | Double_t c =GetSigmaY2()*GetSigmaZ2(); | |
138 | if (c>co) return 1; | |
139 | else if (c<co) return -1; | |
140 | return 0; | |
141 | } | |
142 | ||
143 | //_____________________________________________________________________________ | |
144 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { | |
145 | //------------------------------------------------------------------------- | |
146 | // This function returns an external representation of the covriance matrix. | |
147 | // (See comments in AliTPCtrack.h about external track representation) | |
148 | //------------------------------------------------------------------------- | |
149 | Double_t a=GetConvConst(); | |
150 | ||
151 | cc[0 ]=fC00; | |
152 | cc[1 ]=fC10; cc[2 ]=fC11; | |
153 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; | |
154 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; | |
155 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; | |
156 | } | |
157 | ||
158 | //____________________________________________________________________________ | |
159 | Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) { | |
160 | //------------------------------------------------------------------ | |
161 | //This function propagates a track to the minimal distance from the origin | |
162 | //------------------------------------------------------------------ | |
163 | //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. | |
164 | Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2)); | |
165 | Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf); | |
166 | Double_t xv=(snf - fP2)/fP4 + fX; | |
167 | return PropagateTo(xv,d,x0); | |
168 | } | |
169 | ||
170 | //____________________________________________________________________________ | |
171 | Int_t AliITStrackV2:: | |
172 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { | |
173 | //------------------------------------------------------------------ | |
174 | //This function returns a track position in the global system | |
175 | //------------------------------------------------------------------ | |
176 | Double_t dx=xk-fX; | |
177 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
178 | if (TMath::Abs(f2) >= 0.9999) { | |
179 | Int_t n=GetNumberOfClusters(); | |
180 | if (n>kWARN) | |
181 | cerr<<n<<" AliITStrackV2::GetGlobalXYZat: Propagation failed !\n"; | |
182 | return 0; | |
183 | } | |
184 | ||
185 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); | |
186 | ||
187 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); | |
188 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
189 | ||
190 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); | |
191 | x = xk*cs - yk*sn; | |
192 | y = xk*sn + yk*cs; | |
193 | z = zk; | |
194 | ||
195 | return 1; | |
196 | } | |
197 | ||
198 | //_____________________________________________________________________________ | |
199 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const | |
200 | { | |
201 | //----------------------------------------------------------------- | |
202 | // This function calculates a predicted chi2 increment. | |
203 | //----------------------------------------------------------------- | |
204 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
205 | r00+=fC00; r01+=fC10; r11+=fC11; | |
206 | ||
207 | Double_t det=r00*r11 - r01*r01; | |
208 | if (TMath::Abs(det) < 1.e-30) { | |
209 | Int_t n=GetNumberOfClusters(); | |
210 | if (n>kWARN) | |
211 | cerr<<n<<" AliKalmanTrack::GetPredictedChi2: Singular matrix !\n"; | |
212 | return 1e10; | |
213 | } | |
214 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; | |
215 | ||
216 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; | |
217 | ||
218 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; | |
219 | } | |
220 | ||
221 | //_____________________________________________________________________________ | |
222 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c,Double_t *m, | |
223 | Double_t x0) const { | |
224 | //----------------------------------------------------------------- | |
225 | // This function calculates a chi2 increment with a vertex contraint | |
226 | //----------------------------------------------------------------- | |
227 | TVectorD x(5); x(0)=fP0; x(1)=fP1; x(2)=fP2; x(3)=fP3; x(4)=fP4; | |
228 | TMatrixD C(5,5); | |
229 | C(0,0)=fC00; | |
230 | C(1,0)=fC10; C(1,1)=fC11; | |
231 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; | |
232 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; | |
233 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; | |
234 | ||
235 | C(0,1)=C(1,0); | |
236 | C(0,2)=C(2,0); C(1,2)=C(2,1); | |
237 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); | |
238 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); | |
239 | ||
240 | TMatrixD H(4,5); H.UnitMatrix(); | |
241 | Double_t dy=(c->GetY() - m[0]), dz=(c->GetZ() - m[1]); | |
242 | ||
243 | Double_t dr=TMath::Sqrt(fX*fX + dy*dy); | |
244 | Double_t r =TMath::Sqrt(4/dr/dr - fP4*fP4); | |
245 | Double_t sn=0.5*(fP4*fX + dy*r); | |
246 | Double_t tg=0.5*fP4*dz/TMath::ASin(0.5*fP4*dr); | |
247 | TVectorD mm(4); | |
248 | mm(0)=m[0]=c->GetY(); mm(1)=m[1]=c->GetZ(); mm(2)=m[2]=sn; mm(3)=m[3]=tg; | |
249 | ||
250 | Double_t v22=0.,v33=0.; | |
251 | //x0=0.; | |
252 | if (x0!=0.) { | |
253 | Double_t pp2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
254 | Double_t beta2=pp2/(pp2 + GetMass()*GetMass()); | |
255 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
256 | Double_t theta2=14.1*14.1/(beta2*pp2*1e6)*x0; | |
257 | v22 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
258 | v33 = theta2*(1.+ GetTgl()*GetTgl())*(1. + GetTgl()*GetTgl()); | |
259 | } | |
260 | Double_t sy2=c->GetSigmaY2(), sz2=c->GetSigmaZ2(); | |
261 | v22+=fSigmaYV*fSigmaYV/dr/dr; | |
262 | v22+=sy2/dr/dr; | |
263 | Double_t v20=sy2/dr; | |
264 | ||
265 | v33+=fSigmaZV*fSigmaZV/dr/dr; | |
266 | v33+=sz2/dr/dr; | |
267 | Double_t v31=sz2/dr; | |
268 | ||
269 | TMatrixD V(4,4); | |
270 | V(0,0)=m[4 ]=sy2; V(0,1)=m[5 ]=0.; V(0,2)=m[6 ]=v20; V(0,3)=m[7 ]=0.; | |
271 | V(1,0)=m[8 ]=0.; V(1,1)=m[9 ]=sz2; V(1,2)=m[10]=0.; V(1,3)=m[11]=v31; | |
272 | V(2,0)=m[12]=v20; V(2,1)=m[13]=0.; V(2,2)=m[14]=v22; V(2,3)=m[15]=0.; | |
273 | V(3,0)=m[16]=0.; V(3,1)=m[17]=v31; V(3,2)=m[18]=0.; V(3,3)=m[19]=v33; | |
274 | ||
275 | TVectorD res=x; res*=H; res-=mm; //res*=-1; | |
276 | TMatrixD tmp(H,TMatrixD::kMult,C); | |
277 | TMatrixD R(tmp,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed,H)); R+=V; | |
278 | ||
279 | Double_t det=R.Determinant(); | |
280 | if (TMath::Abs(det) < 1.e-30) { | |
281 | Int_t n=GetNumberOfClusters(); | |
282 | if (n>kWARN) | |
283 | cerr<<n<<" AliITStrackV2::GetPredictedChi2: Singular matrix !\n"; | |
284 | return 1e10; | |
285 | } | |
286 | ||
287 | R.Invert(); | |
288 | ||
289 | TVectorD rs=res; | |
290 | res*=R; | |
291 | return rs*res; | |
292 | } | |
293 | ||
294 | //____________________________________________________________________________ | |
295 | Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) { | |
296 | //------------------------------------------------------------------ | |
297 | //This function corrects the track parameters for crossed material | |
298 | //------------------------------------------------------------------ | |
299 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
300 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
301 | d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); | |
302 | ||
303 | //Multiple scattering****************** | |
304 | if (d!=0) { | |
305 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d); | |
306 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33; | |
307 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); | |
308 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); | |
309 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); | |
310 | fC44 += theta2*fP3*fP4*fP3*fP4; | |
311 | } | |
312 | ||
313 | //Energy losses************************ | |
314 | if (x0!=0.) { | |
315 | d*=x0; | |
316 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d; | |
317 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); | |
318 | } | |
319 | ||
320 | if (!Invariant()) return 0; | |
321 | ||
322 | return 1; | |
323 | } | |
324 | ||
325 | //____________________________________________________________________________ | |
326 | Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { | |
327 | //------------------------------------------------------------------ | |
328 | //This function propagates a track | |
329 | //------------------------------------------------------------------ | |
330 | Double_t x1=fX, x2=xk, dx=x2-x1; | |
331 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
332 | if (TMath::Abs(f2) >= 0.9999) { | |
333 | Int_t n=GetNumberOfClusters(); | |
334 | if (n>kWARN) | |
335 | cerr<<n<<" AliITStrackV2::PropagateTo: Propagation failed !\n"; | |
336 | return 0; | |
337 | } | |
338 | ||
339 | // old position [SR, GSI, 17.02.2003] | |
340 | Double_t oldX = fX, oldY = fP0, oldZ = fP1; | |
341 | ||
342 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); | |
343 | ||
344 | fP0 += dx*(f1+f2)/(r1+r2); | |
345 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
346 | fP2 += dx*fP4; | |
347 | ||
348 | //f = F - 1 | |
349 | ||
350 | Double_t f02= dx/(r1*r1*r1); | |
351 | Double_t f04=0.5*dx*dx/(r1*r1*r1); | |
352 | Double_t f12= dx*fP3*f1/(r1*r1*r1); | |
353 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); | |
354 | Double_t f13= dx/r1; | |
355 | Double_t f24= dx; | |
356 | ||
357 | //b = C*ft | |
358 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; | |
359 | Double_t b02=f24*fC40; | |
360 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; | |
361 | Double_t b12=f24*fC41; | |
362 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; | |
363 | Double_t b22=f24*fC42; | |
364 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; | |
365 | Double_t b42=f24*fC44; | |
366 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; | |
367 | Double_t b32=f24*fC43; | |
368 | ||
369 | //a = f*b = f*C*ft | |
370 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; | |
371 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; | |
372 | Double_t a22=f24*b42; | |
373 | ||
374 | //F*C*Ft = C + (b + bt + a) | |
375 | fC00 += b00 + b00 + a00; | |
376 | fC10 += b10 + b01 + a01; | |
377 | fC20 += b20 + b02 + a02; | |
378 | fC30 += b30; | |
379 | fC40 += b40; | |
380 | fC11 += b11 + b11 + a11; | |
381 | fC21 += b21 + b12 + a12; | |
382 | fC31 += b31; | |
383 | fC41 += b41; | |
384 | fC22 += b22 + b22 + a22; | |
385 | fC32 += b32; | |
386 | fC42 += b42; | |
387 | ||
388 | fX=x2; | |
389 | ||
390 | if (!CorrectForMaterial(d,x0)) return 0; | |
391 | ||
392 | // Integrated Time [SR, GSI, 17.02.2003] | |
393 | if (IsStartedTimeIntegral()) { | |
394 | Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+(fP1-oldZ)*(fP1-oldZ); | |
395 | AddTimeStep(TMath::Sqrt(l2)); | |
396 | } | |
397 | // | |
398 | ||
399 | return 1; | |
400 | } | |
401 | ||
402 | //____________________________________________________________________________ | |
403 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { | |
404 | //------------------------------------------------------------------ | |
405 | //This function updates track parameters | |
406 | //------------------------------------------------------------------ | |
407 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; | |
408 | Double_t c00=fC00; | |
409 | Double_t c10=fC10, c11=fC11; | |
410 | Double_t c20=fC20, c21=fC21, c22=fC22; | |
411 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; | |
412 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; | |
413 | ||
414 | ||
415 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
416 | r00+=fC00; r01+=fC10; r11+=fC11; | |
417 | Double_t det=r00*r11 - r01*r01; | |
418 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; | |
419 | ||
420 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; | |
421 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; | |
422 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; | |
423 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; | |
424 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; | |
425 | ||
426 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; | |
427 | Double_t sf=fP2 + k20*dy + k21*dz; | |
428 | ||
429 | fP0 += k00*dy + k01*dz; | |
430 | fP1 += k10*dy + k11*dz; | |
431 | fP2 = sf; | |
432 | fP3 += k30*dy + k31*dz; | |
433 | fP4 += k40*dy + k41*dz; | |
434 | ||
435 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; | |
436 | Double_t c12=fC21, c13=fC31, c14=fC41; | |
437 | ||
438 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; | |
439 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; | |
440 | fC40-=k00*c04+k01*c14; | |
441 | ||
442 | fC11-=k10*c01+k11*fC11; | |
443 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; | |
444 | fC41-=k10*c04+k11*c14; | |
445 | ||
446 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; | |
447 | fC42-=k20*c04+k21*c14; | |
448 | ||
449 | fC33-=k30*c03+k31*c13; | |
450 | fC43-=k30*c04+k31*c14; | |
451 | ||
452 | fC44-=k40*c04+k41*c14; | |
453 | ||
454 | if (!Invariant()) { | |
455 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; | |
456 | fC00=c00; | |
457 | fC10=c10; fC11=c11; | |
458 | fC20=c20; fC21=c21; fC22=c22; | |
459 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; | |
460 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; | |
461 | return 0; | |
462 | } | |
463 | ||
464 | Int_t n=GetNumberOfClusters(); | |
465 | fIndex[n]=index; | |
466 | SetNumberOfClusters(n+1); | |
467 | SetChi2(GetChi2()+chi2); | |
468 | ||
469 | return 1; | |
470 | } | |
471 | ||
472 | Int_t AliITStrackV2::Invariant() const { | |
473 | //------------------------------------------------------------------ | |
474 | // This function is for debugging purpose only | |
475 | //------------------------------------------------------------------ | |
476 | Int_t n=GetNumberOfClusters(); | |
477 | ||
478 | if (TMath::Abs(fP2)>=0.9999){ | |
479 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fP2="<<fP2<<endl; | |
480 | return 0; | |
481 | } | |
482 | if (fC00<=0 || fC00>9.) { | |
483 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC00="<<fC00<<endl; | |
484 | return 0; | |
485 | } | |
486 | if (fC11<=0 || fC11>9.) { | |
487 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC11="<<fC11<<endl; | |
488 | return 0; | |
489 | } | |
490 | if (fC22<=0 || fC22>1.) { | |
491 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC22="<<fC22<<endl; | |
492 | return 0; | |
493 | } | |
494 | if (fC33<=0 || fC33>1.) { | |
495 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC33="<<fC33<<endl; | |
496 | return 0; | |
497 | } | |
498 | if (fC44<=0 || fC44>6e-5) { | |
499 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC44="<<fC44<<endl; | |
500 | return 0; | |
501 | } | |
502 | return 1; | |
503 | } | |
504 | ||
505 | //____________________________________________________________________________ | |
506 | Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { | |
507 | //------------------------------------------------------------------ | |
508 | //This function propagates a track | |
509 | //------------------------------------------------------------------ | |
510 | Double_t alpha=fAlpha, x=fX; | |
511 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; | |
512 | Double_t c00=fC00; | |
513 | Double_t c10=fC10, c11=fC11; | |
514 | Double_t c20=fC20, c21=fC21, c22=fC22; | |
515 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; | |
516 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; | |
517 | ||
518 | if (alp < -TMath::Pi()) alp += 2*TMath::Pi(); | |
519 | else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi(); | |
520 | Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha); | |
521 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); | |
522 | ||
523 | TMatrixD *T=0; | |
524 | // **** rotation ********************** | |
525 | { | |
526 | fAlpha = alp; | |
527 | fX = x*ca + p0*sa; | |
528 | fP0= -x*sa + p0*ca; | |
529 | fP2= sf*ca - cf*sa; | |
530 | ||
531 | TMatrixD C(5,5); | |
532 | C(0,0)=c00; | |
533 | C(1,0)=c10; C(1,1)=c11; | |
534 | C(2,0)=c20; C(2,1)=c21; C(2,2)=c22; | |
535 | C(3,0)=c30; C(3,1)=c31; C(3,2)=c32; C(3,3)=c33; | |
536 | C(4,0)=c40; C(4,1)=c41; C(4,2)=c42; C(4,3)=c43; C(4,4)=c44; | |
537 | C(0,1)=C(1,0); | |
538 | C(0,2)=C(2,0); C(1,2)=C(2,1); | |
539 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); | |
540 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); | |
541 | ||
542 | TMatrixD F(6,5); | |
543 | F(0,0)=sa; | |
544 | F(1,0)=ca; | |
545 | F(2,1)=F(4,3)=F(5,4)=1; | |
546 | F(3,2)=ca + sf/cf*sa; | |
547 | ||
548 | TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); | |
549 | T=new TMatrixD(F,TMatrixD::kMult,tmp); | |
550 | } | |
551 | ||
552 | // **** translation ****************** | |
553 | { | |
554 | Double_t dx=xk-fX; | |
555 | Double_t f1=fP2, f2=f1 + fP4*dx; | |
556 | if (TMath::Abs(f2) >= 0.9999) { | |
557 | Int_t n=GetNumberOfClusters(); | |
558 | if (n>kWARN) | |
559 | cerr<<n<<" AliITStrackV2::Propagate: Propagation failed !\n"; | |
560 | return 0; | |
561 | } | |
562 | Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2); | |
563 | ||
564 | fX=xk; | |
565 | fP0 += dx*(f1+f2)/(r1+r2); | |
566 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; | |
567 | fP2 += dx*fP4; | |
568 | ||
569 | TMatrixD F(5,6); | |
570 | F(0,1)=F(1,2)=F(2,3)=F(3,4)=F(4,5)=1; | |
571 | F(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2)); | |
572 | F(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2)); | |
573 | F(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1)); | |
574 | F(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1); | |
575 | F(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1)); | |
576 | F(2,5)=dx; | |
577 | F(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2)); | |
578 | F(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1))); | |
579 | F(2,0)=-fP4; | |
580 | ||
581 | TMatrixD tmp(*T,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); | |
582 | delete T; | |
583 | TMatrixD C(F,TMatrixD::kMult,tmp); | |
584 | ||
585 | fC00=C(0,0); | |
586 | fC10=C(1,0); fC11=C(1,1); | |
587 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); | |
588 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); | |
589 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); | |
590 | ||
591 | if (!Invariant()) { | |
592 | fAlpha=alpha; | |
593 | fX=x; | |
594 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; | |
595 | fC00=c00; | |
596 | fC10=c10; fC11=c11; | |
597 | fC20=c20; fC21=c21; fC22=c22; | |
598 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; | |
599 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; | |
600 | return 0; | |
601 | } | |
602 | } | |
603 | ||
604 | return 1; | |
605 | } | |
606 | ||
607 | Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const { | |
608 | //------------------------------------------------------------------ | |
609 | // This function calculates the transverse impact parameter | |
610 | // with respect to a point with global coordinates (x,y) | |
611 | //------------------------------------------------------------------ | |
612 | Double_t xt=fX, yt=fP0; | |
613 | ||
614 | Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha); | |
615 | Double_t a = x*cs + y*sn; | |
616 | y = -x*sn + y*cs; x=a; | |
617 | xt-=x; yt-=y; | |
618 | ||
619 | sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2); | |
620 | a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt); | |
621 | if (fP4<0) a=-a; | |
622 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); | |
623 | } | |
624 | ||
625 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { | |
626 | //------------------------------------------------------------------ | |
627 | //This function improves angular track parameters | |
628 | //------------------------------------------------------------------ | |
629 | Double_t dy=fP0-yv, dz=fP1-zv; | |
630 | Double_t r2=fX*fX+dy*dy; | |
631 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
632 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
633 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
634 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; | |
635 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
636 | { | |
637 | Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); | |
638 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
639 | sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); | |
640 | sigma2p += fSigmaYV*fSigmaYV/r2; | |
641 | sigma2p += 0.25*fC44*fX*fX; | |
642 | Double_t eps2p=sigma2p/(fC22+sigma2p); | |
643 | fP0 += fC20/(fC22+sigma2p)*(parp-fP2); | |
644 | fP2 = eps2p*fP2 + (1-eps2p)*parp; | |
645 | fC22 *= eps2p; | |
646 | fC20 *= eps2p; | |
647 | } | |
648 | { | |
649 | Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); | |
650 | Double_t sigma2l=theta2; | |
651 | sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); | |
652 | sigma2l += fSigmaZV*fSigmaZV/r2; | |
653 | Double_t eps2l=sigma2l/(fC33+sigma2l); | |
654 | fP1 += fC31/(fC33+sigma2l)*(parl-fP3); | |
655 | fP4 += fC43/(fC33+sigma2l)*(parl-fP3); | |
656 | fP3 = eps2l*fP3 + (1-eps2l)*parl; | |
657 | fC33 *= eps2l; fC43 *= eps2l; | |
658 | fC31 *= eps2l; | |
659 | } | |
660 | if (!Invariant()) return 0; | |
661 | return 1; | |
662 | } | |
663 | ||
664 | /* | |
665 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { | |
666 | //------------------------------------------------------------------ | |
667 | //This function improves angular track parameters | |
668 | //------------------------------------------------------------------ | |
669 | Double_t dy=fP0-yv, dz=fP1-zv; | |
670 | Double_t r2=fX*fX+dy*dy; | |
671 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); | |
672 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
673 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
674 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; | |
675 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
676 | ||
677 | Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); | |
678 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); | |
679 | sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); | |
680 | sigma2 += kSigmaYV*kSigmaYV/r2; | |
681 | sigma2 += 0.25*fC44*fX*fX; | |
682 | Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2); | |
683 | if (10*r2*fC44<fC22) { | |
684 | fP2 = eps2*fP2 + (1-eps2)*par; | |
685 | fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps; | |
686 | } | |
687 | ||
688 | par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); | |
689 | sigma2=theta2; | |
690 | sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); | |
691 | sigma2 += kSigmaZV*kSigmaZV/r2; | |
692 | eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2); | |
693 | Double_t tgl=fP3; | |
694 | fP3 = eps2*fP3 + (1-eps2)*par; | |
695 | fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps; | |
696 | ||
697 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); | |
698 | fP4*=eps; | |
699 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; | |
700 | ||
701 | if (!Invariant()) return 0; | |
702 | return 1; | |
703 | } | |
704 | */ | |
705 | void AliITStrackV2::ResetCovariance() { | |
706 | //------------------------------------------------------------------ | |
707 | //This function makes a track forget its history :) | |
708 | //------------------------------------------------------------------ | |
709 | ||
710 | fC00*=10.; | |
711 | fC10=0.; fC11*=10.; | |
712 | fC20=0.; fC21=0.; fC22*=10.; | |
713 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; | |
714 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; | |
715 | ||
716 | } | |
717 | ||
718 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { | |
719 | //----------------------------------------------------------------- | |
720 | // This function calculates dE/dX within the "low" and "up" cuts. | |
721 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
722 | //----------------------------------------------------------------- | |
723 | Int_t i; | |
724 | Int_t nc=4; | |
725 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 | |
726 | // Take only SSD and SDD | |
727 | ||
728 | Int_t swap;//stupid sorting | |
729 | do { | |
730 | swap=0; | |
731 | for (i=0; i<nc-1; i++) { | |
732 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; | |
733 | Float_t tmp=fdEdxSample[i]; | |
734 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; | |
735 | swap++; | |
736 | } | |
737 | } while (swap); | |
738 | ||
739 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX | |
740 | // values from four ones choose | |
741 | // nu=2 | |
742 | Float_t dedx=0; | |
743 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; | |
744 | dedx /= (nu-nl); | |
745 | ||
746 | SetdEdx(dedx); | |
747 | } |