1 /**************************************************************************
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4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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14 **************************************************************************/
18 ///////////////////////////////////////////////////////////////////////////
19 // Implementation of the ITS track class
21 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
22 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
23 ///////////////////////////////////////////////////////////////////////////
26 #include "AliCluster.h"
27 #include "AliESDtrack.h"
28 #include "AliESDVertex.h"
29 #include "AliITSReconstructor.h"
30 #include "AliITStrackV2.h"
31 #include "AliTracker.h"
33 const Int_t AliITStrackV2::fgkWARN = 5;
35 ClassImp(AliITStrackV2)
38 //____________________________________________________________________________
39 AliITStrackV2::AliITStrackV2() : AliKalmanTrack(),
40 fCheckInvariant(kTRUE),
44 for(Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) {fIndex[i]=-1; fModule[i]=-1;}
45 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
49 //____________________________________________________________________________
50 AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
52 fCheckInvariant(kTRUE),
53 fdEdx(t.GetITSsignal()),
56 //------------------------------------------------------------------
57 // Conversion ESD track -> ITS track.
58 // If c==kTRUE, create the ITS track out of the constrained params.
59 //------------------------------------------------------------------
60 const AliExternalTrackParam *par=&t;
62 par=t.GetConstrainedParam();
63 if (!par) throw "AliITStrackV2: conversion failed !\n";
65 Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance());
67 //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
69 SetLabel(t.GetLabel());
71 SetNumberOfClusters(t.GetITSclusters(fIndex));
73 if (t.GetStatus()&AliESDtrack::kTIME) {
75 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
76 SetIntegratedLength(t.GetIntegratedLength());
79 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
82 //____________________________________________________________________________
83 void AliITStrackV2::ResetClusters() {
84 //------------------------------------------------------------------
85 // Reset the array of attached clusters.
86 //------------------------------------------------------------------
87 for (Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) fIndex[i]=-1;
89 SetNumberOfClusters(0);
92 //____________________________________________________________________________
93 void AliITStrackV2::UpdateESDtrack(ULong_t flags) const {
94 // Update track params
95 fESDtrack->UpdateTrackParams(this,flags);
96 // copy the module indices
97 for(Int_t i=0;i<12;i++) {
98 // printf(" %d\n",GetModuleIndex(i));
99 fESDtrack->SetITSModuleIndex(i,GetModuleIndex(i));
101 // copy the 4 dedx samples
102 Double_t sdedx[4]={0.,0.,0.,0.};
103 for(Int_t i=0; i<4; i++) sdedx[i]=fdEdxSample[i];
104 fESDtrack->SetITSdEdxSamples(sdedx);
107 //____________________________________________________________________________
108 AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) :
110 fCheckInvariant(t.fCheckInvariant),
112 fESDtrack(t.fESDtrack)
114 //------------------------------------------------------------------
116 //------------------------------------------------------------------
118 for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i];
119 for (i=0; i<2*AliITSgeomTGeo::GetNLayers(); i++) {
120 fIndex[i]=t.fIndex[i];
121 fModule[i]=t.fModule[i];
125 //_____________________________________________________________________________
126 Int_t AliITStrackV2::Compare(const TObject *o) const {
127 //-----------------------------------------------------------------
128 // This function compares tracks according to the their curvature
129 //-----------------------------------------------------------------
130 AliITStrackV2 *t=(AliITStrackV2*)o;
131 //Double_t co=OneOverPt();
132 //Double_t c =OneOverPt();
133 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
134 Double_t c =GetSigmaY2()*GetSigmaZ2();
136 else if (c<co) return -1;
140 //____________________________________________________________________________
142 AliITStrackV2::PropagateToVertex(const AliESDVertex *v,Double_t d,Double_t x0)
144 //------------------------------------------------------------------
145 //This function propagates a track to the minimal distance from the origin
146 //------------------------------------------------------------------
148 if (PropagateToDCA(v,bz,kVeryBig)) {
149 Double_t xOverX0,xTimesRho;
150 xOverX0 = d; xTimesRho = d*x0;
151 if (CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kTRUE;
156 //____________________________________________________________________________
157 Bool_t AliITStrackV2::
158 GetGlobalXYZat(Double_t xloc, Double_t &x, Double_t &y, Double_t &z) const {
159 //------------------------------------------------------------------
160 //This function returns a track position in the global system
161 //------------------------------------------------------------------
163 Bool_t rc=GetXYZAt(xloc, GetBz(), r);
164 x=r[0]; y=r[1]; z=r[2];
168 //_____________________________________________________________________________
169 Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const {
170 //-----------------------------------------------------------------
171 // This function calculates a predicted chi2 increment.
172 //-----------------------------------------------------------------
173 Double_t p[2]={c->GetY(), c->GetZ()};
174 Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
175 return AliExternalTrackParam::GetPredictedChi2(p,cov);
178 //____________________________________________________________________________
179 Bool_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) {
180 //------------------------------------------------------------------
181 //This function propagates a track
182 //------------------------------------------------------------------
184 Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
186 //Double_t bz=GetBz();
187 //if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
188 Double_t b[3]; GetBxByBz(b);
189 if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) return kFALSE;
190 Double_t xOverX0,xTimesRho;
191 xOverX0 = d; xTimesRho = d*x0;
192 if (!CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kFALSE;
194 Double_t x=GetX(), y=GetY(), z=GetZ();
195 if (IsStartedTimeIntegral() && x>oldX) {
196 Double_t l2 = (x-oldX)*(x-oldX) + (y-oldY)*(y-oldY) + (z-oldZ)*(z-oldZ);
197 AddTimeStep(TMath::Sqrt(l2));
203 //____________________________________________________________________________
204 Bool_t AliITStrackV2::PropagateToTGeo(Double_t xToGo, Int_t nstep, Double_t &xOverX0, Double_t &xTimesRho, Bool_t addTime) {
205 //-------------------------------------------------------------------
206 // Propagates the track to a reference plane x=xToGo in n steps.
207 // These n steps are only used to take into account the curvature.
208 // The material is calculated with TGeo. (L.Gaudichet)
209 //-------------------------------------------------------------------
211 Double_t startx = GetX(), starty = GetY(), startz = GetZ();
212 Double_t sign = (startx<xToGo) ? -1.:1.;
213 Double_t step = (xToGo-startx)/TMath::Abs(nstep);
215 Double_t start[3], end[3], mparam[7];
216 //Double_t bz = GetBz();
217 Double_t b[3]; GetBxByBz(b);
222 for (Int_t i=0; i<nstep; i++) {
224 GetXYZ(start); //starting global position
226 if (!GetXYZAt(x, bz, end)) return kFALSE;
227 //if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE;
228 if (!AliExternalTrackParam::PropagateToBxByBz(x, b)) return kFALSE;
229 AliTracker::MeanMaterialBudget(start, end, mparam);
230 xTimesRho = sign*mparam[4]*mparam[0];
232 if (mparam[1]<900000) {
233 if (!AliExternalTrackParam::CorrectForMeanMaterial(xOverX0,
234 xTimesRho,GetMass())) return kFALSE;
235 } else { // this happens when MeanMaterialBudget cannot cross a boundary
240 if (addTime && IsStartedTimeIntegral() && GetX()>startx) {
241 Double_t l2 = ( (GetX()-startx)*(GetX()-startx) +
242 (GetY()-starty)*(GetY()-starty) +
243 (GetZ()-startz)*(GetZ()-startz) );
244 AddTimeStep(TMath::Sqrt(l2));
250 //____________________________________________________________________________
251 Bool_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, Int_t index)
253 //------------------------------------------------------------------
254 //This function updates track parameters
255 //------------------------------------------------------------------
256 Double_t p[2]={c->GetY(), c->GetZ()};
257 Double_t cov[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
259 if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
261 Int_t n=GetNumberOfClusters();
263 if (n>fgkWARN) AliWarning("Wrong invariant !");
267 if (chi2<0) return kTRUE;
269 // fill residuals for ITS+TPC tracks
271 if (fESDtrack->GetStatus()&AliESDtrack::kTPCin) {
272 AliTracker::FillResiduals(this,p,cov,c->GetVolumeId());
277 SetNumberOfClusters(n+1);
278 SetChi2(GetChi2()+chi2);
283 Bool_t AliITStrackV2::Invariant() const {
284 //------------------------------------------------------------------
285 // This function is for debugging purpose only
286 //------------------------------------------------------------------
287 if(!fCheckInvariant) return kTRUE;
289 Int_t n=GetNumberOfClusters();
291 // take into account the misalignment error
292 Float_t maxMisalErrY2=0,maxMisalErrZ2=0;
293 for (Int_t lay=0; lay<AliITSgeomTGeo::kNLayers; lay++) {
294 maxMisalErrY2 = TMath::Max(maxMisalErrY2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorY(lay,GetBz()));
295 maxMisalErrZ2 = TMath::Max(maxMisalErrZ2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorZ(lay,GetBz()));
297 maxMisalErrY2 *= maxMisalErrY2;
298 maxMisalErrZ2 *= maxMisalErrZ2;
299 // this is because when we reset before refitting, we multiply the
301 maxMisalErrY2 *= 10.;
302 maxMisalErrZ2 *= 10.;
304 Double_t sP2=GetParameter()[2];
305 if (TMath::Abs(sP2) >= kAlmost1){
306 if (n>fgkWARN) Warning("Invariant","fP2=%f\n",sP2);
309 Double_t sC00=GetCovariance()[0];
310 if (sC00<=0 || sC00>(9.+maxMisalErrY2)) {
311 if (n>fgkWARN) Warning("Invariant","fC00=%f\n",sC00);
314 Double_t sC11=GetCovariance()[2];
315 if (sC11<=0 || sC11>(9.+maxMisalErrZ2)) {
316 if (n>fgkWARN) Warning("Invariant","fC11=%f\n",sC11);
319 Double_t sC22=GetCovariance()[5];
320 if (sC22<=0 || sC22>1.) {
321 if (n>fgkWARN) Warning("Invariant","fC22=%f\n",sC22);
324 Double_t sC33=GetCovariance()[9];
325 if (sC33<=0 || sC33>1.) {
326 if (n>fgkWARN) Warning("Invariant","fC33=%f\n",sC33);
329 Double_t sC44=GetCovariance()[14];
330 if (sC44<=0 /*|| sC44>6e-5*/) {
331 if (n>fgkWARN) Warning("Invariant","fC44=%f\n",sC44);
338 //____________________________________________________________________________
339 Bool_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) {
340 //------------------------------------------------------------------
341 //This function propagates a track
342 //------------------------------------------------------------------
343 //Double_t bz=GetBz();
344 //if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE;
345 Double_t b[3]; GetBxByBz(b);
346 if (!AliExternalTrackParam::PropagateBxByBz(alp,xk,b)) return kFALSE;
349 Int_t n=GetNumberOfClusters();
350 if (n>fgkWARN) AliWarning("Wrong invariant !");
357 Bool_t AliITStrackV2::MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const {
359 //-------------------------------------------------------------------
360 // Get the mean material budget between the actual point and the
361 // primary vertex. (L.Gaudichet)
362 //-------------------------------------------------------------------
364 Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
365 Double_t vertexX = xyz[0]*cs + xyz[1]*sn;
367 Int_t nstep = Int_t((GetX()-vertexX)/step);
368 if (nstep<1) nstep = 1;
369 step = (GetX()-vertexX)/nstep;
371 // Double_t mparam[7], densMean=0, radLength=0, length=0;
373 Double_t p1[3], p2[3], x = GetX(), bz = GetBz();
378 for (Int_t i=0; i<nstep; i++) {
380 if (!GetXYZAt(x, bz, p2)) return kFALSE;
381 AliTracker::MeanMaterialBudget(p1, p2, mparam);
382 if (mparam[1]>900000) return kFALSE;
393 Bool_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) {
394 //------------------------------------------------------------------
395 //This function improves angular track parameters
396 //------------------------------------------------------------------
397 //Store the initail track parameters
399 return kTRUE; //PH temporary switched off
402 Double_t alpha = GetAlpha();
403 Double_t par[] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()};
423 Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
424 //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
425 Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
426 Double_t zv = xyz[2]; // local frame
428 Double_t dy = par[0] - yv, dz = par[1] - zv;
429 Double_t r2=GetX()*GetX() + dy*dy;
430 Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt());
431 Double_t beta2=p2/(p2 + GetMass()*GetMass());
432 x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
433 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
434 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
436 Double_t cnv=GetBz()*kB2C;
438 Double_t dummy = 4/r2 - GetC()*GetC();
439 if (dummy < 0) return kFALSE;
440 Double_t parp = 0.5*(GetC()*GetX() + dy*TMath::Sqrt(dummy));
441 Double_t sigma2p = theta2*(1.-GetSnp())*(1.+GetSnp())*(1. + GetTgl()*GetTgl());
442 Double_t ovSqr2 = 1./TMath::Sqrt(r2);
443 Double_t tfact = ovSqr2*(1.-dy*ovSqr2)*(1.+dy*ovSqr2);
444 sigma2p += cov[0]*tfact*tfact;
445 sigma2p += ers[1]*ers[1]/r2;
446 sigma2p += 0.25*cov[14]*cnv*cnv*GetX()*GetX();
447 Double_t eps2p=sigma2p/(cov[5] + sigma2p);
448 par[0] += cov[3]/(cov[5] + sigma2p)*(parp - GetSnp());
449 par[2] = eps2p*GetSnp() + (1 - eps2p)*parp;
454 Double_t parl=0.5*GetC()*dz/TMath::ASin(0.5*GetC()*TMath::Sqrt(r2));
455 Double_t sigma2l=theta2;
456 sigma2l += cov[2]/r2 + cov[0]*dy*dy*dz*dz/(r2*r2*r2);
457 sigma2l += ers[2]*ers[2]/r2;
458 Double_t eps2l = sigma2l/(cov[9] + sigma2l);
459 par[1] += cov[7 ]/(cov[9] + sigma2l)*(parl - par[3]);
460 par[4] += cov[13]/(cov[9] + sigma2l)*(parl - par[3]);
461 par[3] = eps2l*par[3] + (1-eps2l)*parl;
467 Set(x,alpha,par,cov);
469 if (!Invariant()) return kFALSE;
474 void AliITStrackV2::CookdEdx(Double_t low, Double_t up) {
475 //-----------------------------------------------------------------
476 // This function calculates dE/dX within the "low" and "up" cuts.
477 // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
478 // Updated: F. Prino 8-June-2009
479 //-----------------------------------------------------------------
480 // The cluster order is: SDD-1, SDD-2, SSD-1, SSD-2
484 for (Int_t il=0; il<4; il++) { // count good (>0) dE/dx values
485 if(fdEdxSample[il]>0.){
486 dedx[nc]= fdEdxSample[il];
495 Int_t swap; // sort in ascending order
498 for (Int_t i=0; i<nc-1; i++) {
499 if (dedx[i]<=dedx[i+1]) continue;
508 Double_t nl=low*nc, nu =up*nc;
510 Float_t sumweight =0;
511 for (Int_t i=0; i<nc; i++) {
513 if (i<nl+0.1) weight = TMath::Max(1.-(nl-i),0.);
514 if (i>nu-1) weight = TMath::Max(nu-i,0.);
515 sumamp+= dedx[i]*weight;
518 SetdEdx(sumamp/sumweight);
521 //____________________________________________________________________________
522 Bool_t AliITStrackV2::
523 GetPhiZat(Double_t r, Double_t &phi, Double_t &z) const {
524 //------------------------------------------------------------------
525 // This function returns the global cylindrical (phi,z) of the track
526 // position estimated at the radius r.
527 // The track curvature is neglected.
528 //------------------------------------------------------------------
529 Double_t d=GetD(0.,0.);
530 if (TMath::Abs(d) > r) {
531 if (r>1e-1) return kFALSE;
535 Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
536 if (TMath::Abs(d) > rcurr) return kFALSE;
537 Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
538 Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
541 phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
543 phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
546 // return a phi in [0,2pi[
547 if (phi<0.) phi+=2.*TMath::Pi();
548 else if (phi>=2.*TMath::Pi()) phi-=2.*TMath::Pi();
549 z=GetZ()+GetTgl()*(TMath::Sqrt((r-d)*(r+d))-TMath::Sqrt((rcurr-d)*(rcurr+d)));
552 //____________________________________________________________________________
553 Bool_t AliITStrackV2::
554 GetLocalXat(Double_t r,Double_t &xloc) const {
555 //------------------------------------------------------------------
556 // This function returns the local x of the track
557 // position estimated at the radius r.
558 // The track curvature is neglected.
559 //------------------------------------------------------------------
560 Double_t d=GetD(0.,0.);
561 if (TMath::Abs(d) > r) {
562 if (r>1e-1) return kFALSE;
566 Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
567 Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
568 Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
571 phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
573 phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
576 xloc=r*(TMath::Cos(phi)*TMath::Cos(GetAlpha())
577 +TMath::Sin(phi)*TMath::Sin(GetAlpha()));