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 tracker class
18 // It reads AliITSRecPoint clusters and creates AliITStrackV2 tracks
19 // and fills with them the ESD
20 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
21 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
22 //-------------------------------------------------------------------------
30 #include "AliITSgeom.h"
31 #include "AliITSRecPoint.h"
33 #include "AliITSRecPoint.h"
34 #include "AliITStrackerV2.h"
36 ClassImp(AliITStrackerV2)
38 AliITStrackerV2::AliITSlayer AliITStrackerV2::fgLayers[kMaxLayer]; // ITS layers
40 AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
41 //--------------------------------------------------------------------
42 //This is the AliITStrackerV2 constructor
43 //--------------------------------------------------------------------
44 AliITSgeom *g=(AliITSgeom*)geom;
46 Float_t x,y,z; Int_t i;
47 for (i=1; i<kMaxLayer+1; i++) {
48 Int_t nlad=g->GetNladders(i);
49 Int_t ndet=g->GetNdetectors(i);
51 g->GetTrans(i,1,1,x,y,z);
52 Double_t r=TMath::Sqrt(x*x + y*y);
53 Double_t poff=TMath::ATan2(y,x);
56 g->GetTrans(i,1,2,x,y,z);
57 r += TMath::Sqrt(x*x + y*y);
58 g->GetTrans(i,2,1,x,y,z);
59 r += TMath::Sqrt(x*x + y*y);
60 g->GetTrans(i,2,2,x,y,z);
61 r += TMath::Sqrt(x*x + y*y);
64 new (fgLayers+i-1) AliITSlayer(r,poff,zoff,nlad,ndet);
66 for (Int_t j=1; j<nlad+1; j++) {
67 for (Int_t k=1; k<ndet+1; k++) { //Fill this layer with detectors
68 Float_t x,y,zshift; g->GetTrans(i,j,k,x,y,zshift);
69 Double_t rot[9]; g->GetRotMatrix(i,j,k,rot);
71 Double_t phi=TMath::ATan2(rot[1],rot[0])+TMath::Pi();
73 if (i==1) phi+=TMath::Pi();
75 if (phi<0) phi+=TMath::TwoPi();
76 else if (phi>=TMath::TwoPi()) phi-=TMath::TwoPi();
78 Double_t cp=TMath::Cos(phi), sp=TMath::Sin(phi);
81 AliITSdetector &det=fgLayers[i-1].GetDetector((j-1)*ndet + k-1);
82 new(&det) AliITSdetector(r,phi);
91 fConstraint[0]=1; fConstraint[1]=0;
93 Double_t xyz[]={kXV,kYV,kZV}, ers[]={kSigmaXV,kSigmaYV,kSigmaZV};
96 for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=kLayersNotToSkip[i];
97 fLastLayerToTrackTo=kLastLayerToTrackTo;
101 void AliITStrackerV2::SetLayersNotToSkip(Int_t *l) {
102 //--------------------------------------------------------------------
103 //This function set masks of the layers which must be not skipped
104 //--------------------------------------------------------------------
105 for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=l[i];
108 Int_t AliITStrackerV2::LoadClusters(TTree *cTree) {
109 //--------------------------------------------------------------------
110 //This function loads ITS clusters
111 //--------------------------------------------------------------------
112 TBranch *branch=cTree->GetBranch("ITSRecPoints");
114 Error("LoadClusters"," can't get the branch !\n");
118 TClonesArray dummy("AliITSRecPoint",10000), *clusters=&dummy;
119 branch->SetAddress(&clusters);
122 for (Int_t i=0; i<kMaxLayer; i++) {
123 Int_t ndet=fgLayers[i].GetNdetectors();
124 Int_t jmax = j + fgLayers[i].GetNladders()*ndet;
126 Double_t r=fgLayers[i].GetR();
127 Double_t circ=TMath::TwoPi()*r;
129 for (; j<jmax; j++) {
130 if (!cTree->GetEvent(j)) continue;
131 Int_t ncl=clusters->GetEntriesFast();
133 AliITSRecPoint *c=(AliITSRecPoint*)clusters->UncheckedAt(ncl);
135 Int_t idx=c->GetDetectorIndex();
136 Double_t y=r*fgLayers[i].GetDetector(idx).GetPhi()+c->GetY();
137 if (y>circ) y-=circ; else if (y<0) y+=circ;
140 fgLayers[i].InsertCluster(new AliITSRecPoint(*c));
144 fgLayers[i].ResetRoad(); //road defined by the cluster density
150 void AliITStrackerV2::UnloadClusters() {
151 //--------------------------------------------------------------------
152 //This function unloads ITS clusters
153 //--------------------------------------------------------------------
154 for (Int_t i=0; i<kMaxLayer; i++) fgLayers[i].ResetClusters();
157 static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
158 //--------------------------------------------------------------------
159 // Correction for the material between the TPC and the ITS
160 // (should it belong to the TPC code ?)
161 //--------------------------------------------------------------------
162 Double_t riw=80., diw=0.0053, x0iw=30; // TPC inner wall ?
163 Double_t rcd=61., dcd=0.0053, x0cd=30; // TPC "central drum" ?
164 Double_t yr=12.8, dr=0.03; // rods ?
165 Double_t zm=0.2, dm=0.40; // membrane
166 //Double_t rr=52., dr=0.19, x0r=24., yyr=7.77; //rails
167 Double_t rs=50., ds=0.001; // something belonging to the ITS (screen ?)
169 if (t->GetX() > riw) {
170 if (!t->PropagateTo(riw,diw,x0iw)) return 1;
171 if (TMath::Abs(t->GetY())>yr) t->CorrectForMaterial(dr);
172 if (TMath::Abs(t->GetZ())<zm) t->CorrectForMaterial(dm);
173 if (!t->PropagateTo(rcd,dcd,x0cd)) return 1;
174 //Double_t x,y,z; t->GetGlobalXYZat(rr,x,y,z);
175 //if (TMath::Abs(y)<yyr) t->PropagateTo(rr,dr,x0r);
176 if (!t->PropagateTo(rs,ds)) return 1;
177 } else if (t->GetX() < rs) {
178 if (!t->PropagateTo(rs,-ds)) return 1;
179 //Double_t x,y,z; t->GetGlobalXYZat(rr,x,y,z);
180 //if (TMath::Abs(y)<yyr) t->PropagateTo(rr,-dr,x0r);
181 if (!t->PropagateTo(rcd,-dcd,x0cd)) return 1;
182 if (!t->PropagateTo(riw+0.001,-diw,x0iw)) return 1;
184 ::Error("CorrectForDeadZoneMaterial","track is already in the dead zone !");
191 Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
192 //--------------------------------------------------------------------
193 // This functions reconstructs ITS tracks
194 // The clusters must be already loaded !
195 //--------------------------------------------------------------------
196 TObjArray itsTracks(15000);
198 {/* Read ESD tracks */
199 Int_t nentr=event->GetNumberOfTracks();
200 Info("Clusters2Tracks", "Number of ESD tracks: %d\n", nentr);
202 AliESDtrack *esd=event->GetTrack(nentr);
204 if ((esd->GetStatus()&AliESDtrack::kTPCin)==0) continue;
205 if (esd->GetStatus()&AliESDtrack::kTPCout) continue;
206 if (esd->GetStatus()&AliESDtrack::kITSin) continue;
210 t=new AliITStrackV2(*esd);
211 } catch (const Char_t *msg) {
212 Warning("Clusters2Tracks",msg);
216 if (TMath::Abs(t->GetD())>4) {
221 if (CorrectForDeadZoneMaterial(t)!=0) {
222 Warning("Clusters2Tracks",
223 "failed to correct for the material in the dead zone !\n");
227 itsTracks.AddLast(t);
229 } /* End Read ESD tracks */
232 Int_t nentr=itsTracks.GetEntriesFast();
235 for (fPass=0; fPass<2; fPass++) {
236 Int_t &constraint=fConstraint[fPass]; if (constraint<0) continue;
237 for (Int_t i=0; i<nentr; i++) {
238 AliITStrackV2 *t=(AliITStrackV2*)itsTracks.UncheckedAt(i);
239 if (t==0) continue; //this track has been already tracked
240 Int_t tpcLabel=t->GetLabel(); //save the TPC track label
242 ResetTrackToFollow(*t);
245 for (FollowProlongation(); fI<kMaxLayer; fI++) {
246 while (TakeNextProlongation()) FollowProlongation();
249 if (fBestTrack.GetNumberOfClusters() == 0) continue;
251 if (fConstraint[fPass]) {
252 ResetTrackToFollow(*t);
253 if (!RefitAt(3.7, &fTrackToFollow, &fBestTrack)) continue;
257 fBestTrack.SetLabel(tpcLabel);
258 fBestTrack.CookdEdx();
259 CookLabel(&fBestTrack,0.); //For comparison only
260 fBestTrack.UpdateESDtrack(AliESDtrack::kITSin);
261 UseClusters(&fBestTrack);
262 delete itsTracks.RemoveAt(i);
269 Info("Clusters2Tracks","Number of prolonged tracks: %d\n",ntrk);
274 Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
275 //--------------------------------------------------------------------
276 // This functions propagates reconstructed ITS tracks back
277 // The clusters must be loaded !
278 //--------------------------------------------------------------------
279 Int_t nentr=event->GetNumberOfTracks();
280 Info("PropagateBack", "Number of ESD tracks: %d\n", nentr);
283 for (Int_t i=0; i<nentr; i++) {
284 AliESDtrack *esd=event->GetTrack(i);
286 if ((esd->GetStatus()&AliESDtrack::kITSin)==0) continue;
287 if (esd->GetStatus()&AliESDtrack::kITSout) continue;
291 t=new AliITStrackV2(*esd);
292 } catch (const Char_t *msg) {
293 Warning("PropagateBack",msg);
298 ResetTrackToFollow(*t);
300 // propagete to vertex [SR, GSI 17.02.2003]
301 // Start Time measurement [SR, GSI 17.02.2003], corrected by I.Belikov
302 if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {
303 if (fTrackToFollow.PropagateToVertex()) {
304 fTrackToFollow.StartTimeIntegral();
306 fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
309 fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
310 if (RefitAt(49.,&fTrackToFollow,t)) {
311 if (CorrectForDeadZoneMaterial(&fTrackToFollow)!=0) {
312 Warning("PropagateBack",
313 "failed to correct for the material in the dead zone !\n");
317 fTrackToFollow.SetLabel(t->GetLabel());
318 //fTrackToFollow.CookdEdx();
319 CookLabel(&fTrackToFollow,0.); //For comparison only
320 fTrackToFollow.UpdateESDtrack(AliESDtrack::kITSout);
321 UseClusters(&fTrackToFollow);
327 Info("PropagateBack","Number of back propagated ITS tracks: %d\n",ntrk);
332 Int_t AliITStrackerV2::RefitInward(AliESD *event) {
333 //--------------------------------------------------------------------
334 // This functions refits ITS tracks using the
335 // "inward propagated" TPC tracks
336 // The clusters must be loaded !
337 //--------------------------------------------------------------------
338 Int_t nentr=event->GetNumberOfTracks();
339 Info("RefitInward", "Number of ESD tracks: %d\n", nentr);
342 for (Int_t i=0; i<nentr; i++) {
343 AliESDtrack *esd=event->GetTrack(i);
345 if ((esd->GetStatus()&AliESDtrack::kITSout) == 0) continue;
346 if (esd->GetStatus()&AliESDtrack::kITSrefit) continue;
347 if (esd->GetStatus()&AliESDtrack::kTPCout)
348 if ((esd->GetStatus()&AliESDtrack::kTPCrefit)==0) continue;
352 t=new AliITStrackV2(*esd);
353 } catch (const Char_t *msg) {
354 Warning("RefitInward",msg);
359 if (CorrectForDeadZoneMaterial(t)!=0) {
360 Warning("RefitInward",
361 "failed to correct for the material in the dead zone !\n");
366 ResetTrackToFollow(*t);
367 fTrackToFollow.ResetClusters();
370 if (RefitAt(3.7, &fTrackToFollow, t, kTRUE)) {
371 fTrackToFollow.SetLabel(t->GetLabel());
372 fTrackToFollow.CookdEdx();
373 CookLabel(&fTrackToFollow,0.); //For comparison only
375 if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {//The beam pipe
376 AliESDtrack *esdTrack =fTrackToFollow.GetESDtrack();
377 esdTrack->UpdateTrackParams(&fTrackToFollow,AliESDtrack::kITSrefit);
378 Float_t r[3]={0.,0.,0.};
380 esdTrack->RelateToVertex(event->GetVertex(),GetBz(r),maxD);
387 Info("RefitInward","Number of refitted tracks: %d\n",ntrk);
392 AliCluster *AliITStrackerV2::GetCluster(Int_t index) const {
393 //--------------------------------------------------------------------
394 // Return pointer to a given cluster
395 //--------------------------------------------------------------------
396 Int_t l=(index & 0xf0000000) >> 28;
397 Int_t c=(index & 0x0fffffff) >> 00;
398 return fgLayers[l].GetCluster(c);
402 void AliITStrackerV2::FollowProlongation() {
403 //--------------------------------------------------------------------
404 //This function finds a track prolongation
405 //--------------------------------------------------------------------
406 while (fI>fLastLayerToTrackTo) {
409 AliITSlayer &layer=fgLayers[i];
410 AliITStrackV2 &track=fTracks[i];
412 Double_t r=layer.GetR();
415 Double_t rs=0.5*(fgLayers[i+1].GetR() + r);
416 Double_t d=0.0034, x0=38.6;
417 if (i==1) {rs=9.; d=0.0097; x0=42;}
418 if (!fTrackToFollow.PropagateTo(rs,d,x0)) {
419 //Warning("FollowProlongation","propagation failed !\n");
426 if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z)) {
427 //Warning("FollowProlongation","failed to estimate track !\n");
430 Double_t phi=TMath::ATan2(y,x);
432 Int_t idet=layer.FindDetectorIndex(phi,z);
434 //Warning("FollowProlongation","failed to find a detector !\n");
438 //propagate to the intersection
439 const AliITSdetector &det=layer.GetDetector(idet);
441 if (!fTrackToFollow.Propagate(phi,det.GetR())) {
442 //Warning("FollowProlongation","propagation failed !\n");
445 fTrackToFollow.SetDetectorIndex(idet);
447 //Select possible prolongations and store the current track estimation
448 track.~AliITStrackV2(); new(&track) AliITStrackV2(fTrackToFollow);
449 Double_t dz=7*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[i]);
450 Double_t dy=7*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[i]);
451 Double_t road=layer.GetRoad();
452 if (dz*dy>road*road) {
453 Double_t dd=TMath::Sqrt(dz*dy), scz=dz/dd, scy=dy/dd;
454 dz=road*scz; dy=road*scy;
457 //Double_t dz=4*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[i]);
458 if (dz < 0.5*TMath::Abs(track.GetTgl())) dz=0.5*TMath::Abs(track.GetTgl());
460 //Warning("FollowProlongation","too broad road in Z !\n");
464 if (TMath::Abs(fTrackToFollow.GetZ()-GetZ()) > r+dz) return;
466 //Double_t dy=4*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[i]);
467 if (dy < 0.5*TMath::Abs(track.GetSnp())) dy=0.5*TMath::Abs(track.GetSnp());
469 //Warning("FollowProlongation","too broad road in Y !\n");
475 Double_t zmin=track.GetZ() - dz;
476 Double_t zmax=track.GetZ() + dz;
477 Double_t ymin=track.GetY() + r*phi - dy;
478 Double_t ymax=track.GetY() + r*phi + dy;
479 if (layer.SelectClusters(zmin,zmax,ymin,ymax)==0)
480 if (fLayersNotToSkip[fI]) return;
482 if (!TakeNextProlongation())
483 if (fLayersNotToSkip[fI]) return;
487 //deal with the best track
488 Int_t ncl=fTrackToFollow.GetNumberOfClusters();
489 Int_t nclb=fBestTrack.GetNumberOfClusters();
492 Double_t chi2=fTrackToFollow.GetChi2();
493 if (chi2/ncl < kChi2PerCluster) {
494 if (ncl > nclb || chi2 < fBestTrack.GetChi2()) {
502 Int_t AliITStrackerV2::TakeNextProlongation() {
503 //--------------------------------------------------------------------
504 // This function takes another track prolongation
506 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
507 //--------------------------------------------------------------------
508 AliITSlayer &layer=fgLayers[fI];
509 ResetTrackToFollow(fTracks[fI]);
511 Double_t dz=7*TMath::Sqrt(fTrackToFollow.GetSigmaZ2() + kSigmaZ2[fI]);
512 Double_t dy=7*TMath::Sqrt(fTrackToFollow.GetSigmaY2() + kSigmaY2[fI]);
513 Double_t road=layer.GetRoad();
514 if (dz*dy>road*road) {
515 Double_t dd=TMath::Sqrt(dz*dy), scz=dz/dd, scy=dy/dd;
516 dz=road*scz; dy=road*scy;
519 const AliITSRecPoint *c=0; Int_t ci=-1;
520 const AliITSRecPoint *cc=0; Int_t cci=-1;
521 Double_t chi2=kMaxChi2;
522 while ((c=layer.GetNextCluster(ci))!=0) {
523 Int_t idet=c->GetDetectorIndex();
525 if (fTrackToFollow.GetDetectorIndex()!=idet) {
526 const AliITSdetector &det=layer.GetDetector(idet);
527 ResetTrackToFollow(fTracks[fI]);
528 if (!fTrackToFollow.Propagate(det.GetPhi(),det.GetR())) {
529 //Warning("TakeNextProlongation","propagation failed !\n");
532 fTrackToFollow.SetDetectorIndex(idet);
533 if (TMath::Abs(fTrackToFollow.GetZ()-GetZ())>layer.GetR()+dz) continue;
536 if (TMath::Abs(fTrackToFollow.GetZ() - c->GetZ()) > dz) continue;
537 if (TMath::Abs(fTrackToFollow.GetY() - c->GetY()) > dy) continue;
539 Double_t ch2=fTrackToFollow.GetPredictedChi2(c);
540 if (ch2 > chi2) continue;
548 if (!fTrackToFollow.Update(cc,chi2,(fI<<28)+cci)) {
549 //Warning("TakeNextProlongation","filtering failed !\n");
553 if (fTrackToFollow.GetNumberOfClusters()>1)
554 if (TMath::Abs(fTrackToFollow.GetD())>4) return 0;
557 SetSampledEdx(cc->GetQ(),fTrackToFollow.GetNumberOfClusters()-1); //b.b.
561 Double_t d=layer.GetThickness(fTrackToFollow.GetY(),fTrackToFollow.GetZ(),x0);
562 fTrackToFollow.CorrectForMaterial(d,x0);
565 if (fConstraint[fPass]) {
566 Double_t d=GetEffectiveThickness(0,0); //Think of this !!!!
567 Double_t xyz[]={GetX(),GetY(),GetZ()};
568 Double_t ers[]={GetSigmaX(),GetSigmaY(),GetSigmaZ()};
569 fTrackToFollow.Improve(d,xyz,ers);
576 AliITStrackerV2::AliITSlayer::AliITSlayer() {
577 //--------------------------------------------------------------------
578 //default AliITSlayer constructor
579 //--------------------------------------------------------------------
580 fR=0.; fPhiOffset=0.; fZOffset=0.;
581 fNladders=0; fNdetectors=0;
584 for (Int_t i=0; i<kNsector; i++) fN[i]=0;
587 fRoad=2*fR*TMath::Sqrt(3.14/1.);//assuming that there's only one cluster
590 AliITStrackerV2::AliITSlayer::
591 AliITSlayer(Double_t r,Double_t p,Double_t z,Int_t nl,Int_t nd) {
592 //--------------------------------------------------------------------
593 //main AliITSlayer constructor
594 //--------------------------------------------------------------------
595 fR=r; fPhiOffset=p; fZOffset=z;
596 fNladders=nl; fNdetectors=nd;
597 fDetectors=new AliITSdetector[fNladders*fNdetectors];
599 for (Int_t i=0; i<kNsector; i++) fN[i]=0;
602 for (Int_t i=0; i<kMaxClusterPerLayer; i++) fClusters[i]=0;
604 fRoad=2*fR*TMath::Sqrt(3.14/1.);//assuming that there's only one cluster
607 AliITStrackerV2::AliITSlayer::~AliITSlayer() {
608 //--------------------------------------------------------------------
609 // AliITSlayer destructor
610 //--------------------------------------------------------------------
615 void AliITStrackerV2::AliITSlayer::ResetClusters() {
616 //--------------------------------------------------------------------
617 // This function removes loaded clusters
618 //--------------------------------------------------------------------
619 for (Int_t s=0; s<kNsector; s++) {
623 delete fClusters[s*kMaxClusterPerSector+n];
628 void AliITStrackerV2::AliITSlayer::ResetRoad() {
629 //--------------------------------------------------------------------
630 // This function calculates the road defined by the cluster density
631 //--------------------------------------------------------------------
633 for (Int_t s=0; s<kNsector; s++) {
636 if (TMath::Abs(fClusters[s*kMaxClusterPerSector+i]->GetZ())<fR) n++;
638 if (n>1) fRoad=2*fR*TMath::Sqrt(3.14/n);
641 Int_t AliITStrackerV2::AliITSlayer::InsertCluster(AliITSRecPoint *c) {
642 //--------------------------------------------------------------------
643 // This function inserts a cluster to this layer in increasing
644 // order of the cluster's fZ
645 //--------------------------------------------------------------------
646 Float_t circ=TMath::TwoPi()*fR;
647 Int_t sec=Int_t(kNsector*c->GetPhiR()/circ);
649 ::Error("InsertCluster","Wrong sector !\n");
653 if (n>=kMaxClusterPerSector) {
654 ::Error("InsertCluster","Too many clusters !\n");
657 if (n==0) fClusters[sec*kMaxClusterPerSector]=c;
659 Int_t i=FindClusterIndex(c->GetZ(),sec);
660 Int_t k=n-i+sec*kMaxClusterPerSector;
661 memmove(fClusters+i+1 ,fClusters+i,k*sizeof(AliITSRecPoint*));
669 AliITStrackerV2::AliITSlayer::FindClusterIndex(Float_t z,Int_t s) const {
670 //--------------------------------------------------------------------
671 // For the sector "s", this function returns the index of the first
672 // with its fZ >= "z".
673 //--------------------------------------------------------------------
675 if (nc==0) return kMaxClusterPerSector*s;
677 Int_t b=kMaxClusterPerSector*s;
678 if (z <= fClusters[b]->GetZ()) return b;
681 if (z > fClusters[e]->GetZ()) return e+1;
684 for (; b<e; m=(b+e)/2) {
685 if (z > fClusters[m]->GetZ()) b=m+1;
691 Int_t AliITStrackerV2::AliITSlayer::
692 SelectClusters(Float_t zmin,Float_t zmax,Float_t ymin, Float_t ymax) {
693 //--------------------------------------------------------------------
694 // This function selects clusters within the "window"
695 //--------------------------------------------------------------------
696 Float_t circ=fR*TMath::TwoPi();
698 if (ymin>circ) ymin-=circ; else if (ymin<0) ymin+=circ;
699 if (ymax>circ) ymax-=circ; else if (ymax<0) ymax+=circ;
701 Int_t i1=Int_t(kNsector*ymin/circ); if (i1==kNsector) i1--;
703 Float_t ym = (ymax<ymin) ? ymax+circ : ymax;
704 Int_t i=FindClusterIndex(zmin,i1), imax=i1*kMaxClusterPerSector+fN[i1];
705 for (; i<imax; i++) {
706 AliITSRecPoint *c=fClusters[i];
707 if (c->IsUsed()) continue;
708 if (c->GetZ()>zmax) break;
709 if (c->GetPhiR()<=ymin) continue;
710 if (c->GetPhiR()>ym) continue;
715 Int_t i2=Int_t(kNsector*ymax/circ); if (i2==kNsector) i2--;
716 if (i2==i1) return fNsel;
719 Float_t ym = (ymin>ymax) ? ymin-circ : ymin;
720 Int_t i=FindClusterIndex(zmin,i2), imax=i2*kMaxClusterPerSector+fN[i2];
721 for (; i<imax; i++) {
722 AliITSRecPoint *c=fClusters[i];
723 if (c->IsUsed()) continue;
724 if (c->GetZ()>zmax) break;
725 if (c->GetPhiR()<=ym) continue;
726 if (c->GetPhiR()>ymax) continue;
734 const AliITSRecPoint *AliITStrackerV2::AliITSlayer::GetNextCluster(Int_t &ci){
735 //--------------------------------------------------------------------
736 // This function returns clusters within the "window"
737 //--------------------------------------------------------------------
748 Int_t AliITStrackerV2::AliITSlayer::GetNumberOfClusters() const {
750 for (Int_t s=0; s<kNsector; s++) n+=fN[s];
755 AliITStrackerV2::AliITSlayer::FindDetectorIndex(Double_t phi,Double_t z)const {
756 //--------------------------------------------------------------------
757 //This function finds the detector crossed by the track
758 //--------------------------------------------------------------------
759 Double_t dphi=-(phi-fPhiOffset);
760 if (dphi < 0) dphi += 2*TMath::Pi();
761 else if (dphi >= 2*TMath::Pi()) dphi -= 2*TMath::Pi();
762 Int_t np=Int_t(dphi*fNladders*0.5/TMath::Pi()+0.5);
763 if (np>=fNladders) np-=fNladders;
764 if (np<0) np+=fNladders;
766 Double_t dz=fZOffset-z;
767 Int_t nz=Int_t(dz*(fNdetectors-1)*0.5/fZOffset+0.5);
768 if (nz>=fNdetectors) return -1;
771 return np*fNdetectors + nz;
775 AliITStrackerV2::AliITSlayer::GetThickness(Double_t y,Double_t z,Double_t &x0)
777 //--------------------------------------------------------------------
778 //This function returns the layer thickness at this point (units X0)
779 //--------------------------------------------------------------------
783 if (43<fR&&fR<45) { //SSD2
786 if (TMath::Abs(y-0.00)>3.40) d+=dd;
787 if (TMath::Abs(y-1.90)<0.45) {d+=(0.013-0.0034);}
788 if (TMath::Abs(y+1.90)<0.45) {d+=(0.013-0.0034);}
789 for (Int_t i=0; i<12; i++) {
790 if (TMath::Abs(z-3.9*(i+0.5))<0.15) {
791 if (TMath::Abs(y-0.00)>3.40) d+=dd;
795 if (TMath::Abs(z+3.9*(i+0.5))<0.15) {
796 if (TMath::Abs(y-0.00)>3.40) d+=dd;
800 if (TMath::Abs(z-3.4-3.9*i)<0.50) {d+=(0.016-0.0034); break;}
801 if (TMath::Abs(z+0.5+3.9*i)<0.50) {d+=(0.016-0.0034); break;}
804 if (37<fR&&fR<41) { //SSD1
807 if (TMath::Abs(y-0.00)>3.40) d+=dd;
808 if (TMath::Abs(y-1.90)<0.45) {d+=(0.013-0.0034);}
809 if (TMath::Abs(y+1.90)<0.45) {d+=(0.013-0.0034);}
810 for (Int_t i=0; i<11; i++) {
811 if (TMath::Abs(z-3.9*i)<0.15) {
812 if (TMath::Abs(y-0.00)>3.40) d+=dd;
816 if (TMath::Abs(z+3.9*i)<0.15) {
817 if (TMath::Abs(y-0.00)>3.40) d+=dd;
821 if (TMath::Abs(z-1.85-3.9*i)<0.50) {d+=(0.016-0.0034); break;}
822 if (TMath::Abs(z+2.05+3.9*i)<0.50) {d+=(0.016-0.0034); break;}
825 if (13<fR&&fR<26) { //SDD
828 if (TMath::Abs(y-0.00)>3.30) d+=dd;
830 if (TMath::Abs(y-1.80)<0.55) {
832 for (Int_t j=0; j<20; j++) {
833 if (TMath::Abs(z+0.7+1.47*j)<0.12) {d+=0.08; x0=9.; break;}
834 if (TMath::Abs(z-0.7-1.47*j)<0.12) {d+=0.08; x0=9.; break;}
837 if (TMath::Abs(y+1.80)<0.55) {
839 for (Int_t j=0; j<20; j++) {
840 if (TMath::Abs(z-0.7-1.47*j)<0.12) {d+=0.08; x0=9.; break;}
841 if (TMath::Abs(z+0.7+1.47*j)<0.12) {d+=0.08; x0=9.; break;}
845 for (Int_t i=0; i<4; i++) {
846 if (TMath::Abs(z-7.3*i)<0.60) {
848 if (TMath::Abs(y-0.00)>3.30) d+=dd;
851 if (TMath::Abs(z+7.3*i)<0.60) {
853 if (TMath::Abs(y-0.00)>3.30) d+=dd;
858 if (6<fR&&fR<8) { //SPD2
859 Double_t dd=0.0063; x0=21.5;
861 if (TMath::Abs(y-3.08)>0.5) d+=dd;
862 //if (TMath::Abs(y-3.08)>0.45) d+=dd;
863 if (TMath::Abs(y-3.03)<0.10) {d+=0.014;}
865 if (3<fR&&fR<5) { //SPD1
866 Double_t dd=0.0063; x0=21.5;
868 if (TMath::Abs(y+0.21)>0.6) d+=dd;
869 //if (TMath::Abs(y+0.21)>0.45) d+=dd;
870 if (TMath::Abs(y+0.10)<0.10) {d+=0.014;}
876 Double_t AliITStrackerV2::GetEffectiveThickness(Double_t y,Double_t z) const
878 //--------------------------------------------------------------------
879 //Returns the thickness between the current layer and the vertex (units X0)
880 //--------------------------------------------------------------------
881 Double_t d=0.0028*3*3; //beam pipe
884 Double_t xn=fgLayers[fI].GetR();
885 for (Int_t i=0; i<fI; i++) {
886 Double_t xi=fgLayers[i].GetR();
887 d+=fgLayers[i].GetThickness(y,z,x0)*xi*xi;
896 Double_t xi=0.5*(fgLayers[3].GetR()+fgLayers[4].GetR());
903 Bool_t AliITStrackerV2::RefitAt(Double_t xx,AliITStrackV2 *t,
904 const AliITStrackV2 *c, Bool_t extra) {
905 //--------------------------------------------------------------------
906 // This function refits the track "t" at the position "x" using
907 // the clusters from "c"
908 // If "extra"==kTRUE,
909 // the clusters from overlapped modules get attached to "t"
910 //--------------------------------------------------------------------
911 Int_t index[kMaxLayer];
913 for (k=0; k<kMaxLayer; k++) index[k]=-1;
914 Int_t nc=c->GetNumberOfClusters();
915 for (k=0; k<nc; k++) {
916 Int_t idx=c->GetClusterIndex(k),nl=(idx&0xf0000000)>>28;
920 Int_t from, to, step;
921 if (xx > t->GetX()) {
922 from=0; to=kMaxLayer;
925 from=kMaxLayer-1; to=-1;
929 for (Int_t i=from; i != to; i += step) {
930 AliITSlayer &layer=fgLayers[i];
931 Double_t r=layer.GetR();
934 Double_t hI=i-0.5*step;
935 if (TMath::Abs(hI-1.5)<0.01 || TMath::Abs(hI-3.5)<0.01) {
936 Double_t rs=0.5*(fgLayers[i-step].GetR() + r);
937 Double_t d=0.0034, x0=38.6;
938 if (TMath::Abs(hI-1.5)<0.01) {rs=9.; d=0.0097; x0=42;}
939 if (!t->PropagateTo(rs,-step*d,x0)) {
945 // remember old position [SR, GSI 18.02.2003]
946 Double_t oldX=0., oldY=0., oldZ=0.;
947 if (t->IsStartedTimeIntegral() && step==1) {
948 t->GetGlobalXYZat(t->GetX(),oldX,oldY,oldZ);
953 if (!t->GetGlobalXYZat(r,x,y,z)) {
956 Double_t phi=TMath::ATan2(y,x);
957 Int_t idet=layer.FindDetectorIndex(phi,z);
961 const AliITSdetector &det=layer.GetDetector(idet);
963 if (!t->Propagate(phi,det.GetR())) {
966 t->SetDetectorIndex(idet);
968 const AliITSRecPoint *cl=0;
969 Double_t maxchi2=kMaxChi2;
973 const AliITSRecPoint *c=(AliITSRecPoint *)GetCluster(idx);
974 if (idet != c->GetDetectorIndex()) {
975 idet=c->GetDetectorIndex();
976 const AliITSdetector &det=layer.GetDetector(idet);
977 if (!t->Propagate(det.GetPhi(),det.GetR())) {
980 t->SetDetectorIndex(idet);
982 Double_t chi2=t->GetPredictedChi2(c);
992 if (!t->Update(cl,maxchi2,idx)) {
995 t->SetSampledEdx(cl->GetQ(),t->GetNumberOfClusters()-1);
1000 Double_t d=layer.GetThickness(t->GetY(),t->GetZ(),x0);
1001 t->CorrectForMaterial(-step*d,x0);
1004 if (extra) { //search for extra clusters
1005 AliITStrackV2 tmp(*t);
1006 Double_t dz=4*TMath::Sqrt(tmp.GetSigmaZ2()+kSigmaZ2[i]);
1007 if (dz < 0.5*TMath::Abs(tmp.GetTgl())) dz=0.5*TMath::Abs(tmp.GetTgl());
1008 Double_t dy=4*TMath::Sqrt(t->GetSigmaY2()+kSigmaY2[i]);
1009 if (dy < 0.5*TMath::Abs(tmp.GetSnp())) dy=0.5*TMath::Abs(tmp.GetSnp());
1010 Double_t zmin=t->GetZ() - dz;
1011 Double_t zmax=t->GetZ() + dz;
1012 Double_t ymin=t->GetY() + phi*r - dy;
1013 Double_t ymax=t->GetY() + phi*r + dy;
1014 layer.SelectClusters(zmin,zmax,ymin,ymax);
1016 const AliITSRecPoint *c=0; Int_t ci=-1,cci=-1;
1017 Double_t maxchi2=1000.*kMaxChi2, tolerance=0.1;
1018 while ((c=layer.GetNextCluster(ci))!=0) {
1019 if (idet == c->GetDetectorIndex()) continue;
1021 const AliITSdetector &det=layer.GetDetector(c->GetDetectorIndex());
1023 if (!tmp.Propagate(det.GetPhi(),det.GetR())) continue;
1025 if (TMath::Abs(tmp.GetZ() - c->GetZ()) > tolerance) continue;
1026 if (TMath::Abs(tmp.GetY() - c->GetY()) > tolerance) continue;
1028 Double_t chi2=tmp.GetPredictedChi2(c);
1029 if (chi2<maxchi2) { maxchi2=chi2; cci=ci; }
1031 if (cci>=0) t->SetExtraCluster(i,(i<<28)+cci);
1034 // track time update [SR, GSI 17.02.2003]
1035 if (t->IsStartedTimeIntegral() && step==1) {
1036 Double_t newX, newY, newZ;
1037 t->GetGlobalXYZat(t->GetX(),newX,newY,newZ);
1038 Double_t dL2 = (oldX-newX)*(oldX-newX) + (oldY-newY)*(oldY-newY) +
1039 (oldZ-newZ)*(oldZ-newZ);
1040 t->AddTimeStep(TMath::Sqrt(dL2));
1046 if (!t->PropagateTo(xx,0.,0.)) return kFALSE;
1050 void AliITStrackerV2::UseClusters(const AliKalmanTrack *t, Int_t from) const {
1051 //--------------------------------------------------------------------
1052 // This function marks clusters assigned to the track
1053 //--------------------------------------------------------------------
1054 AliTracker::UseClusters(t,from);
1056 Int_t clusterIndex = t->GetClusterIndex(0);
1057 AliITSRecPoint *c= 0x0;
1059 if (clusterIndex>-1)
1060 c = (AliITSRecPoint *)GetCluster(clusterIndex);
1061 if (c && c->GetSigmaZ2()>0.1) c->UnUse();
1064 clusterIndex = t->GetClusterIndex(1);
1065 if (clusterIndex>-1)
1066 c=(AliITSRecPoint *)GetCluster(clusterIndex);
1067 if (c && c->GetSigmaZ2()>0.1) c->UnUse();