1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
16 //-------------------------------------------------------------------------
17 // Implementation of the ITS track class
19 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
20 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
21 //-------------------------------------------------------------------------
27 #include "AliCluster.h"
28 #include "AliTPCtrack.h"
29 #include "AliESDtrack.h"
30 #include "AliITStrackV2.h"
32 ClassImp(AliITStrackV2)
36 //____________________________________________________________________________
37 AliITStrackV2::AliITStrackV2():AliKalmanTrack(),
64 fDeadZoneProbability(0),
65 fReconstructed(kFALSE),
69 for(Int_t i=0; i<kMaxLayer; i++) {fIndex[i]=0;fClIndex[i]=-1;}
70 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
71 for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
72 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fChi2MIP[i]=0;}
79 //____________________________________________________________________________
80 AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) :
82 //------------------------------------------------------------------
83 //Conversion TPC track -> ITS track
84 //------------------------------------------------------------------
86 SetNumberOfClusters(0);
91 fAlpha = t.GetAlpha();
92 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
93 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
95 //Conversion of the track parameters
96 Double_t x,p[5]; t.GetExternalParameters(x,p);
97 fX=x; x=GetConvConst();
104 //Conversion of the covariance matrix
105 Double_t c[15]; t.GetExternalCovariance(c);
108 fC10=c[1 ]; fC11=c[2 ];
109 fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ];
110 fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ];
111 fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x;
113 for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
114 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; }
117 if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
121 //____________________________________________________________________________
122 AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
124 //------------------------------------------------------------------
125 // Conversion ESD track -> ITS track.
126 // If c==kTRUE, create the ITS track out of the constrained params.
127 //------------------------------------------------------------------
128 SetNumberOfClusters(t.GetITSclusters(fIndex));
129 SetLabel(t.GetLabel());
130 SetMass(t.GetMass());
134 fdEdx=t.GetITSsignal();
135 fAlpha = t.GetAlpha();
136 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
137 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
139 //Conversion of the track parameters
141 if (c) t.GetConstrainedExternalParameters(x,p);
142 else t.GetExternalParameters(x,p);
143 fX=x; x=GetConvConst();
150 //Conversion of the covariance matrix
152 if (c) t.GetConstrainedExternalCovariance(cv);
153 else t.GetExternalCovariance(cv);
155 fC10=cv[1 ]; fC11=cv[2 ];
156 fC20=cv[3 ]; fC21=cv[4 ]; fC22=cv[5 ];
157 fC30=cv[6 ]; fC31=cv[7 ]; fC32=cv[8 ]; fC33=cv[9 ];
158 fC40=cv[10]/x; fC41=cv[11]/x; fC42=cv[12]/x; fC43=cv[13]/x; fC44=cv[14]/x/x;
160 if (t.GetStatus()&AliESDtrack::kTIME) {
162 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
163 SetIntegratedLength(t.GetIntegratedLength());
167 fReconstructed = kFALSE;
170 fDeadZoneProbability = 0;
171 for(Int_t i=0; i<6; i++) {fClIndex[i]=-1; fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
172 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;fChi2MIP[i]=0;}
179 //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
183 void AliITStrackV2::UpdateESDtrack(ULong_t flags) {
184 fESDtrack->UpdateTrackParams(this,flags);
185 if (flags == AliESDtrack::kITSin) fESDtrack->SetITSChi2MIP(fChi2MIP);
187 void AliITStrackV2::SetConstrainedESDtrack(Double_t chi2) {
188 fESDtrack->SetConstrainedTrackParams(this,chi2);
191 //____________________________________________________________________________
192 AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) {
193 //------------------------------------------------------------------
195 //------------------------------------------------------------------
200 fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4;
203 fC10=t.fC10; fC11=t.fC11;
204 fC20=t.fC20; fC21=t.fC21; fC22=t.fC22;
205 fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33;
206 fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44;
208 Int_t n=GetNumberOfClusters();
209 for (Int_t i=0; i<n; i++) {
210 fIndex[i]=t.fIndex[i];
211 if (i<4) fdEdxSample[i]=t.fdEdxSample[i];
213 fESDtrack=t.fESDtrack;
215 fReconstructed = t.fReconstructed;
216 fNSkipped = t.fNSkipped;
217 fNDeadZone = t.fNDeadZone;
218 fDeadZoneProbability = t.fDeadZoneProbability;
220 fFakeRatio = t.fFakeRatio;
221 fdEdxMismatch = t.fdEdxMismatch;
225 fD[0]=t.fD[0]; fD[1]=t.fD[1];
227 for(Int_t i=0; i<6; i++) {
228 fClIndex[i]= t.fClIndex[i]; fNy[i]=t.fNy[i]; fNz[i]=t.fNz[i]; fNormQ[i]=t.fNormQ[i]; fNormChi2[i] = t.fNormChi2[i];
230 for(Int_t i=0; i<12; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i];
231 fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i];fChi2MIP[i]=t.fChi2MIP[i];}
232 fConstrain = t.fConstrain;
233 //memcpy(fDy,t.fDy,6*sizeof(Float_t));
234 //memcpy(fDz,t.fDz,6*sizeof(Float_t));
235 //memcpy(fSigmaY,t.fSigmaY,6*sizeof(Float_t));
236 //memcpy(fSigmaZ,t.fSigmaZ,6*sizeof(Float_t));
237 //memcpy(fChi2MIP,t.fChi2MIP,12*sizeof(Float_t));
240 //_____________________________________________________________________________
241 Int_t AliITStrackV2::Compare(const TObject *o) const {
242 //-----------------------------------------------------------------
243 // This function compares tracks according to the their curvature
244 //-----------------------------------------------------------------
245 AliITStrackV2 *t=(AliITStrackV2*)o;
246 //Double_t co=TMath::Abs(t->Get1Pt());
247 //Double_t c =TMath::Abs(Get1Pt());
248 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*t->fD[0]*t->fD[0]+t->fD[1]*t->fD[1]));
249 Double_t c =GetSigmaY2()*GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*fD[0]*fD[0]+fD[1]*fD[1]));
251 else if (c<co) return -1;
255 //_____________________________________________________________________________
256 void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const {
257 //-------------------------------------------------------------------------
258 // This function returns an external representation of the covriance matrix.
259 // (See comments in AliTPCtrack.h about external track representation)
260 //-------------------------------------------------------------------------
261 Double_t a=GetConvConst();
264 cc[1 ]=fC10; cc[2 ]=fC11;
265 cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22;
266 cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33;
267 cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a;
270 //____________________________________________________________________________
271 Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) {
272 //------------------------------------------------------------------
273 //This function propagates a track to the minimal distance from the origin
274 //------------------------------------------------------------------
275 //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim.
276 Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2));
277 Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf);
278 Double_t xv=(snf - fP2)/fP4 + fX;
279 return PropagateTo(xv,d,x0);
282 //____________________________________________________________________________
283 Int_t AliITStrackV2::
284 GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const {
285 //------------------------------------------------------------------
286 //This function returns a track position in the global system
287 //------------------------------------------------------------------
289 Double_t f1=fP2, f2=f1 + fP4*dx;
290 if (TMath::Abs(f2) >= 0.9999) {
291 Int_t n=GetNumberOfClusters();
293 Warning("GetGlobalXYZat","Propagation failed (%d) !\n",n);
297 Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2);
299 Double_t yk = fP0 + dx*(f1+f2)/(r1+r2);
300 Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
302 Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha);
310 //_____________________________________________________________________________
311 Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const
313 //-----------------------------------------------------------------
314 // This function calculates a predicted chi2 increment.
315 //-----------------------------------------------------------------
316 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
317 r00+=fC00; r01+=fC10; r11+=fC11;
319 Double_t det=r00*r11 - r01*r01;
320 if (TMath::Abs(det) < 1.e-30) {
321 Int_t n=GetNumberOfClusters();
323 Warning("GetPredictedChi2","Singular matrix (%d) !\n",n);
326 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
328 Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
330 return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
333 Double_t AliITStrackV2::GetPredictedChi2MI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz) const
335 //-----------------------------------------------------------------
336 // This function calculates a predicted chi2 increment.
337 //-----------------------------------------------------------------
338 Double_t r00=cerry*cerry, r01=0., r11=cerrz*cerrz;
339 r00+=fC00; r01+=fC10; r11+=fC11;
341 Double_t det=r00*r11 - r01*r01;
342 if (TMath::Abs(det) < 1.e-30) {
343 Int_t n=GetNumberOfClusters();
345 Warning("GetPredictedChi2","Singular matrix (%d) !\n",n);
348 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
350 Double_t dy=cy - fP0, dz=cz - fP1;
352 return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
355 //____________________________________________________________________________
356 Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) {
357 //------------------------------------------------------------------
358 //This function corrects the track parameters for crossed material
359 //------------------------------------------------------------------
360 // Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
361 Double_t p2=(1.+ fP3*fP3)/(Get1Pt()*Get1Pt());
362 Double_t et = p2 + GetMass()*GetMass();
363 Double_t beta2=p2/et;
365 d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2));
366 //d*=TMath::Sqrt(1.+ fP3*fP3 +fP2*fP2/(1.- fP2*fP2));
368 //Multiple scattering******************
370 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d);
371 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33;
372 fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3);
373 fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3);
374 fC43 += theta2*fP3*fP4*(1. + fP3*fP3);
375 fC44 += theta2*fP3*fP4*fP3*fP4;
378 //Energy losses************************
381 // Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
383 Double_t dE = 0.265*0.153e-3*(39.2-55.6*beta2+28.7*beta2*beta2+27.41/beta2)*d;
385 if (beta2/(1-beta2)>3.5*3.5){
386 dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d;
389 dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
390 dE+=0.06e-3/(beta2*beta2)*d;
394 Double_t delta44 = (dE*fP4*et/p2);
399 if (!Invariant()) return 0;
404 //____________________________________________________________________________
405 Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) {
406 //------------------------------------------------------------------
407 //This function propagates a track
408 //------------------------------------------------------------------
409 Double_t x1=fX, x2=xk, dx=x2-x1;
410 Double_t f1=fP2, f2=f1 + fP4*dx;
411 if (TMath::Abs(f2) >= 0.9999) {
412 Int_t n=GetNumberOfClusters();
414 Warning("PropagateTo","Propagation failed !\n",n);
418 // old position [SR, GSI, 17.02.2003]
419 Double_t oldX = fX, oldY = fP0, oldZ = fP1;
421 Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2);
423 fP0 += dx*(f1+f2)/(r1+r2);
424 fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
429 Double_t f02= dx/(r1*r1*r1);
430 Double_t f04=0.5*dx*dx/(r1*r1*r1);
431 Double_t f12= dx*fP3*f1/(r1*r1*r1);
432 Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1);
437 Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30;
438 Double_t b02=f24*fC40;
439 Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31;
440 Double_t b12=f24*fC41;
441 Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32;
442 Double_t b22=f24*fC42;
443 Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43;
444 Double_t b42=f24*fC44;
445 Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33;
446 Double_t b32=f24*fC43;
449 Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42;
450 Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32;
451 Double_t a22=f24*b42;
453 //F*C*Ft = C + (b + bt + a)
454 fC00 += b00 + b00 + a00;
455 fC10 += b10 + b01 + a01;
456 fC20 += b20 + b02 + a02;
459 fC11 += b11 + b11 + a11;
460 fC21 += b21 + b12 + a12;
463 fC22 += b22 + b22 + a22;
469 if (!CorrectForMaterial(d,x0)) return 0;
471 // Integrated Time [SR, GSI, 17.02.2003]
472 if (IsStartedTimeIntegral() && fX>oldX) {
473 Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+
474 (fP1-oldZ)*(fP1-oldZ);
475 AddTimeStep(TMath::Sqrt(l2));
482 //____________________________________________________________________________
483 Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) {
484 //------------------------------------------------------------------
485 //This function updates track parameters
486 //------------------------------------------------------------------
487 Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
489 Double_t c10=fC10, c11=fC11;
490 Double_t c20=fC20, c21=fC21, c22=fC22;
491 Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
492 Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
495 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
496 r00+=fC00; r01+=fC10; r11+=fC11;
497 Double_t det=r00*r11 - r01*r01;
498 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
501 Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11;
502 Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11;
503 Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11;
504 Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11;
505 Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;
507 Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
508 Int_t layer = (index & 0xf0000000) >> 28;
511 fSigmaY[layer] = TMath::Sqrt(c->GetSigmaY2()+fC00);
512 fSigmaZ[layer] = TMath::Sqrt(c->GetSigmaZ2()+fC11);
514 Double_t sf=fP2 + k20*dy + k21*dz;
516 fP0 += k00*dy + k01*dz;
517 fP1 += k10*dy + k11*dz;
519 fP3 += k30*dy + k31*dz;
520 fP4 += k40*dy + k41*dz;
522 Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
523 Double_t c12=fC21, c13=fC31, c14=fC41;
525 fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11;
526 fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13;
527 fC40-=k00*c04+k01*c14;
529 fC11-=k10*c01+k11*fC11;
530 fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13;
531 fC41-=k10*c04+k11*c14;
533 fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13;
534 fC42-=k20*c04+k21*c14;
536 fC33-=k30*c03+k31*c13;
537 fC43-=k30*c04+k31*c14;
539 fC44-=k40*c04+k41*c14;
542 fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
545 fC20=c20; fC21=c21; fC22=c22;
546 fC30=c30; fC31=c31; fC32=c32; fC33=c33;
547 fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
551 if (chi2<0) return 1;
553 Int_t n=GetNumberOfClusters();
555 SetNumberOfClusters(n+1);
556 SetChi2(GetChi2()+chi2);
561 //____________________________________________________________________________
562 Int_t AliITStrackV2::UpdateMI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz, Double_t chi2,UInt_t index) {
563 //------------------------------------------------------------------
564 //This function updates track parameters
565 //------------------------------------------------------------------
566 Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
568 Double_t c10=fC10, c11=fC11;
569 Double_t c20=fC20, c21=fC21, c22=fC22;
570 Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
571 Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
574 Double_t r00=cerry*cerry, r01=0., r11=cerrz*cerrz;
575 r00+=fC00; r01+=fC10; r11+=fC11;
576 Double_t det=r00*r11 - r01*r01;
577 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
580 Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11;
581 Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11;
582 Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11;
583 Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11;
584 Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;
586 Double_t dy=cy - fP0, dz=cz - fP1;
587 Int_t layer = (index & 0xf0000000) >> 28;
590 fSigmaY[layer] = TMath::Sqrt(cerry*cerry+fC00);
591 fSigmaZ[layer] = TMath::Sqrt(cerrz*cerrz+fC11);
593 Double_t sf=fP2 + k20*dy + k21*dz;
595 fP0 += k00*dy + k01*dz;
596 fP1 += k10*dy + k11*dz;
598 fP3 += k30*dy + k31*dz;
599 fP4 += k40*dy + k41*dz;
601 Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
602 Double_t c12=fC21, c13=fC31, c14=fC41;
604 fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11;
605 fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13;
606 fC40-=k00*c04+k01*c14;
608 fC11-=k10*c01+k11*fC11;
609 fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13;
610 fC41-=k10*c04+k11*c14;
612 fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13;
613 fC42-=k20*c04+k21*c14;
615 fC33-=k30*c03+k31*c13;
616 fC43-=k30*c04+k31*c14;
618 fC44-=k40*c04+k41*c14;
621 fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
624 fC20=c20; fC21=c21; fC22=c22;
625 fC30=c30; fC31=c31; fC32=c32; fC33=c33;
626 fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
630 if (chi2<0) return 1;
631 Int_t n=GetNumberOfClusters();
633 SetNumberOfClusters(n+1);
634 SetChi2(GetChi2()+chi2);
639 Int_t AliITStrackV2::Invariant() const {
640 //------------------------------------------------------------------
641 // This function is for debugging purpose only
642 //------------------------------------------------------------------
643 Int_t n=GetNumberOfClusters();
645 if (TMath::Abs(fP2)>=0.9999){
646 if (n>kWARN) Warning("Invariant","fP2=%f\n",fP2);
649 if (fC00<=0 || fC00>9.) {
650 if (n>kWARN) Warning("Invariant","fC00=%f\n",fC00);
653 if (fC11<=0 || fC11>9.) {
654 if (n>kWARN) Warning("Invariant","fC11=%f\n",fC11);
657 if (fC22<=0 || fC22>1.) {
658 if (n>kWARN) Warning("Invariant","fC22=%f\n",fC22);
661 if (fC33<=0 || fC33>1.) {
662 if (n>kWARN) Warning("Invariant","fC33=%f\n",fC33);
665 if (fC44<=0 || fC44>6e-5) {
666 if (n>kWARN) Warning("Invariant","fC44=%f\n",fC44);
672 //____________________________________________________________________________
673 Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) {
674 //------------------------------------------------------------------
675 //This function propagates a track
676 //------------------------------------------------------------------
677 Double_t alpha=fAlpha, x=fX;
678 Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
680 Double_t c10=fC10, c11=fC11;
681 Double_t c20=fC20, c21=fC21, c22=fC22;
682 Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
683 Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
685 if (alp < -TMath::Pi()) alp += 2*TMath::Pi();
686 else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi();
687 Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha);
688 Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2);
691 // **** rotation **********************
698 static TMatrixD C(5,5);
700 C(1,0)=c10; C(1,1)=c11;
701 C(2,0)=c20; C(2,1)=c21; C(2,2)=c22;
702 C(3,0)=c30; C(3,1)=c31; C(3,2)=c32; C(3,3)=c33;
703 C(4,0)=c40; C(4,1)=c41; C(4,2)=c42; C(4,3)=c43; C(4,4)=c44;
705 C(0,2)=C(2,0); C(1,2)=C(2,1);
706 C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2);
707 C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3);
710 static TMatrixD F(6,5);
713 F(2,1)=F(4,3)=F(5,4)=1;
714 F(3,2)=ca + sf/cf*sa;
716 //TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F));
718 static TMatrixD Ft(5,6);
721 Ft(1,2)=Ft(3,4)=Ft(4,5)=1;
722 Ft(2,3)=ca + sf/cf*sa;
724 TMatrixD tmp(C,TMatrixD::kMult,Ft);
725 T=new TMatrixD(F,TMatrixD::kMult,tmp);
730 // **** translation ******************
733 Double_t f1=fP2, f2=f1 + fP4*dx;
734 if (TMath::Abs(f2) >= 0.9999) {
735 Int_t n=GetNumberOfClusters();
737 Warning("Propagate","Propagation failed (%d) !\n",n);
740 Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
743 fP0 += dx*(f1+f2)/(r1+r2);
744 fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
747 static TMatrixD F(5,6);
748 F(0,1)=F(1,2)=F(2,3)=F(3,4)=F(4,5)=1;
749 F(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2));
750 F(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2));
751 F(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1));
752 F(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1);
753 F(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1));
755 F(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2));
756 F(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1)));
759 TMatrixD tmp(*T,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F));
761 TMatrixD C(F,TMatrixD::kMult,tmp);
764 fC10=C(1,0); fC11=C(1,1);
765 fC20=C(2,0); fC21=C(2,1); fC22=C(2,2);
766 fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3);
767 fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4);
772 fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
775 fC20=c20; fC21=c21; fC22=c22;
776 fC30=c30; fC31=c31; fC32=c32; fC33=c33;
777 fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
787 Int_t AliITStrackV2::GetProlongationFast(Double_t alp, Double_t xk,Double_t &y, Double_t &z)
789 //-----------------------------------------------------------------------------
790 //get fast prolongation
791 //-----------------------------------------------------------------------------
792 Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha);
793 Double_t cf=TMath::Sqrt(1.- fP2*fP2);
794 // **** rotation **********************
796 // **** translation ******************
797 Double_t dx = xk- fX*ca - fP0*sa;
798 Double_t f1=fP2*ca - cf*sa, f2=f1 + fP4*dx;
799 if (TMath::Abs(f2) >= 0.9999) {
802 Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
803 y += dx*(f1+f2)/(r1+r2);
804 z = fP1+dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
809 Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const {
810 //------------------------------------------------------------------
811 // This function calculates the transverse impact parameter
812 // with respect to a point with global coordinates (x,y)
813 //------------------------------------------------------------------
814 Double_t xt=fX, yt=fP0;
816 Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha);
817 Double_t a = x*cs + y*sn;
818 y = -x*sn + y*cs; x=a;
821 sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2);
822 a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt);
824 return a/(1 + TMath::Sqrt(sn*sn + cs*cs));
827 Double_t AliITStrackV2::GetZat(Double_t x) const {
828 //------------------------------------------------------------------
829 // This function calculates the z at given x point - in current coordinate system
830 //------------------------------------------------------------------
831 Double_t x1=fX, x2=x, dx=x2-x1;
833 Double_t f1=fP2, f2=f1 + fP4*dx;
834 if (TMath::Abs(f2) >= 0.9999) {
837 Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2);
838 Double_t z = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
845 Int_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) {
846 //------------------------------------------------------------------
847 //This function improves angular track parameters
848 //------------------------------------------------------------------
849 Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha);
850 //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
851 Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
852 Double_t zv = xyz[2]; // local frame
853 Double_t dy=fP0-yv, dz=fP1-zv;
854 Double_t r2=fX*fX+dy*dy;
855 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
856 Double_t beta2=p2/(p2 + GetMass()*GetMass());
857 x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
858 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
859 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
861 Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4));
862 Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
863 sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
864 sigma2p += ers[1]*ers[1]/r2;
865 sigma2p += 0.25*fC44*fX*fX;
866 Double_t eps2p=sigma2p/(fC22+sigma2p);
867 fP0 += fC20/(fC22+sigma2p)*(parp-fP2);
868 fP2 = eps2p*fP2 + (1-eps2p)*parp;
873 Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2));
874 Double_t sigma2l=theta2;
875 sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2);
876 sigma2l += ers[2]*ers[2]/r2;
877 Double_t eps2l=sigma2l/(fC33+sigma2l);
878 fP1 += fC31/(fC33+sigma2l)*(parl-fP3);
879 fP4 += fC43/(fC33+sigma2l)*(parl-fP3);
880 fP3 = eps2l*fP3 + (1-eps2l)*parl;
881 fC33 *= eps2l; fC43 *= eps2l;
884 if (!Invariant()) return 0;
889 Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) {
890 //------------------------------------------------------------------
891 //This function improves angular track parameters
892 //------------------------------------------------------------------
893 Double_t dy=fP0-yv, dz=fP1-zv;
894 Double_t r2=fX*fX+dy*dy;
895 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
896 Double_t beta2=p2/(p2 + GetMass()*GetMass());
897 x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
898 //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
899 Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
901 Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4));
902 Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
903 sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
904 sigma2 += kSigmaYV*kSigmaYV/r2;
905 sigma2 += 0.25*fC44*fX*fX;
906 Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2);
907 if (10*r2*fC44<fC22) {
908 fP2 = eps2*fP2 + (1-eps2)*par;
909 fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps;
912 par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2));
914 sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2);
915 sigma2 += kSigmaZV*kSigmaZV/r2;
916 eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2);
918 fP3 = eps2*fP3 + (1-eps2)*par;
919 fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps;
921 eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl));
923 fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps;
925 if (!Invariant()) return 0;
929 void AliITStrackV2::ResetCovariance() {
930 //------------------------------------------------------------------
931 //This function makes a track forget its history :)
932 //------------------------------------------------------------------
936 fC20=0.; fC21=0.; fC22*=10.;
937 fC30=0.; fC31=0.; fC32=0.; fC33*=10.;
938 fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.;
942 void AliITStrackV2::CookdEdx(Double_t low, Double_t up) {
943 //-----------------------------------------------------------------
944 // This function calculates dE/dX within the "low" and "up" cuts.
945 // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
946 //-----------------------------------------------------------------
947 // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1
951 for (i=0; i<GetNumberOfClusters(); i++) {
952 Int_t idx=GetClusterIndex(i);
953 idx=(idx&0xf0000000)>>28;
954 if (idx>1) nc++; // Take only SSD and SDD
957 Int_t swap;//stupid sorting
960 for (i=0; i<nc-1; i++) {
961 if (fdEdxSample[i]<=fdEdxSample[i+1]) continue;
962 Float_t tmp=fdEdxSample[i];
963 fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp;
968 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX
969 // values from four ones choose
972 for (i=nl; i<nu; i++) dedx += fdEdxSample[i];
973 if (nu-nl>0) dedx /= (nu-nl);