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 //-------------------------------------------------------------------------
29 #include <TGeoMatrix.h>
31 #include "AliITSgeom.h"
32 #include "AliAlignObj.h"
33 #include "AliITSRecPoint.h"
35 #include "AliITSRecPoint.h"
36 #include "AliITStrackerV2.h"
38 ClassImp(AliITStrackerV2)
40 AliITStrackerV2::AliITSlayer AliITStrackerV2::fgLayers[kMaxLayer]; //ITS layers
42 AliITStrackerV2::AliITStrackerV2():
48 fLastLayerToTrackTo(kLastLayerToTrackTo)
50 //--------------------------------------------------------------------
51 //This is the AliITStrackerV2 default constructor
52 //--------------------------------------------------------------------
54 for (Int_t i=1; i<kMaxLayer+1; i++) new(fgLayers+i-1) AliITSlayer();
56 fConstraint[0]=1; fConstraint[1]=0;
58 Double_t xyz[]={kXV,kYV,kZV}, ers[]={kSigmaXV,kSigmaYV,kSigmaZV};
61 for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=kLayersNotToSkip[i];
65 AliITStrackerV2::AliITStrackerV2(const AliITStrackerV2 &t):
68 fBestTrack(t.fBestTrack),
69 fTrackToFollow(t.fTrackToFollow),
71 fLastLayerToTrackTo(t.fLastLayerToTrackTo)
73 //--------------------------------------------------------------------
74 //This is the AliITStrackerV2 copy constructor
75 //--------------------------------------------------------------------
77 //for (Int_t i=1; i<kMaxLayer+1; i++) new(fgLayers+i-1) AliITSlayer();
79 fConstraint[0]=t.fConstraint[0]; fConstraint[1]=t.fConstraint[1];
81 Double_t xyz[]={kXV,kYV,kZV}, ers[]={kSigmaXV,kSigmaYV,kSigmaZV};
82 xyz[0]=t.GetX(); xyz[1]=t.GetY(); xyz[2]=t.GetZ();
83 ers[0]=t.GetSigmaX(); ers[1]=t.GetSigmaY(); ers[2]=t.GetSigmaZ();
86 for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=t.fLayersNotToSkip[i];
90 AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) :
96 fLastLayerToTrackTo(kLastLayerToTrackTo)
98 //--------------------------------------------------------------------
99 //This is the AliITStrackerV2 constructor
100 //--------------------------------------------------------------------
101 AliITSgeom *g=(AliITSgeom*)geom;
103 Float_t x,y,z; Int_t i;
104 for (i=1; i<kMaxLayer+1; i++) {
105 Int_t nlad=g->GetNladders(i);
106 Int_t ndet=g->GetNdetectors(i);
108 g->GetTrans(i,1,1,x,y,z);
109 Double_t poff=TMath::ATan2(y,x);
111 Double_t r=TMath::Sqrt(x*x + y*y);
113 g->GetTrans(i,1,2,x,y,z);
114 r += TMath::Sqrt(x*x + y*y);
115 g->GetTrans(i,2,1,x,y,z);
116 r += TMath::Sqrt(x*x + y*y);
117 g->GetTrans(i,2,2,x,y,z);
118 r += TMath::Sqrt(x*x + y*y);
121 new (fgLayers+i-1) AliITSlayer(r,poff,zoff,nlad,ndet);
123 for (Int_t j=1; j<nlad+1; j++) {
124 for (Int_t k=1; k<ndet+1; k++) { //Fill this layer with detectors
125 Float_t x,y,zshift; g->GetTrans(i,j,k,x,y,zshift);
126 Double_t rot[9]; g->GetRotMatrix(i,j,k,rot);
128 Double_t phi=TMath::ATan2(rot[1],rot[0])+TMath::Pi();
130 if (i==1) phi+=TMath::Pi();
132 if (phi<0) phi+=TMath::TwoPi();
133 else if (phi>=TMath::TwoPi()) phi-=TMath::TwoPi();
135 Double_t cp=TMath::Cos(phi), sp=TMath::Sin(phi);
136 Double_t r=x*cp+y*sp;
138 AliITSdetector &det=fgLayers[i-1].GetDetector((j-1)*ndet + k-1);
139 new(&det) AliITSdetector(r,phi);
145 fConstraint[0]=1; fConstraint[1]=0;
147 Double_t xyz[]={kXV,kYV,kZV}, ers[]={kSigmaXV,kSigmaYV,kSigmaZV};
150 for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=kLayersNotToSkip[i];
154 void AliITStrackerV2::SetLayersNotToSkip(Int_t *l) {
155 //--------------------------------------------------------------------
156 //This function set masks of the layers which must be not skipped
157 //--------------------------------------------------------------------
158 for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=l[i];
161 Int_t AliITStrackerV2::LoadClusters(TTree *cTree) {
162 //--------------------------------------------------------------------
163 //This function loads ITS clusters
164 //--------------------------------------------------------------------
165 TBranch *branch=cTree->GetBranch("ITSRecPoints");
167 Error("LoadClusters"," can't get the branch !\n");
171 TClonesArray dummy("AliITSRecPoint",10000), *clusters=&dummy;
172 branch->SetAddress(&clusters);
175 for (Int_t i=0; i<kMaxLayer; i++) {
176 Int_t ndet=fgLayers[i].GetNdetectors();
177 Int_t jmax = j + fgLayers[i].GetNladders()*ndet;
179 Double_t r=fgLayers[i].GetR();
180 Double_t circ=TMath::TwoPi()*r;
182 for (; j<jmax; j++) {
183 if (!cTree->GetEvent(j)) continue;
184 Int_t ncl=clusters->GetEntriesFast();
186 AliITSRecPoint *c=(AliITSRecPoint*)clusters->UncheckedAt(ncl);
188 Int_t idx=c->GetDetectorIndex();
189 AliITSdetector &det=fgLayers[i].GetDetector(idx);
191 //Shift the cluster to the misaligned position
192 Double_t x=det.GetR(); //y=...; z=...;
193 c->SetX(x); //c->SetY(y); c->SetZ(z);
195 Double_t y=r*det.GetPhi()+c->GetY();
196 if (y>circ) y-=circ; else if (y<0) y+=circ;
199 fgLayers[i].InsertCluster(new AliITSRecPoint(*c));
203 fgLayers[i].ResetRoad(); //road defined by the cluster density
209 void AliITStrackerV2::UnloadClusters() {
210 //--------------------------------------------------------------------
211 //This function unloads ITS clusters
212 //--------------------------------------------------------------------
213 for (Int_t i=0; i<kMaxLayer; i++) fgLayers[i].ResetClusters();
216 static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
217 //--------------------------------------------------------------------
218 // Correction for the material between the TPC and the ITS
219 // (should it belong to the TPC code ?)
220 //--------------------------------------------------------------------
221 Double_t riw=80., diw=0.0053, x0iw=30; // TPC inner wall ?
222 Double_t rcd=61., dcd=0.0053, x0cd=30; // TPC "central drum" ?
223 Double_t yr=12.8, dr=0.03; // rods ?
224 Double_t zm=0.2, dm=0.40; // membrane
225 //Double_t rr=52., dr=0.19, x0r=24., yyr=7.77; //rails
226 Double_t rs=50., ds=0.001; // something belonging to the ITS (screen ?)
228 if (t->GetX() > riw) {
229 if (!t->PropagateTo(riw,diw,x0iw)) return 1;
230 if (TMath::Abs(t->GetY())>yr) t->CorrectForMaterial(dr);
231 if (TMath::Abs(t->GetZ())<zm) t->CorrectForMaterial(dm);
232 if (!t->PropagateTo(rcd,dcd,x0cd)) return 1;
233 //Double_t x,y,z; t->GetGlobalXYZat(rr,x,y,z);
234 //if (TMath::Abs(y)<yyr) t->PropagateTo(rr,dr,x0r);
235 if (!t->PropagateTo(rs,ds)) return 1;
236 } else if (t->GetX() < rs) {
237 if (!t->PropagateTo(rs,-ds)) return 1;
238 //Double_t x,y,z; t->GetGlobalXYZat(rr,x,y,z);
239 //if (TMath::Abs(y)<yyr) t->PropagateTo(rr,-dr,x0r);
240 if (!t->PropagateTo(rcd,-dcd,x0cd)) return 1;
241 if (!t->PropagateTo(riw+0.001,-diw,x0iw)) return 1;
243 ::Error("CorrectForDeadZoneMaterial","track is already in the dead zone !");
250 Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
251 //--------------------------------------------------------------------
252 // This functions reconstructs ITS tracks
253 // The clusters must be already loaded !
254 //--------------------------------------------------------------------
255 TObjArray itsTracks(15000);
257 {/* Read ESD tracks */
258 Int_t nentr=event->GetNumberOfTracks();
259 Info("Clusters2Tracks", "Number of ESD tracks: %d\n", nentr);
261 AliESDtrack *esd=event->GetTrack(nentr);
263 if ((esd->GetStatus()&AliESDtrack::kTPCin)==0) continue;
264 if (esd->GetStatus()&AliESDtrack::kTPCout) continue;
265 if (esd->GetStatus()&AliESDtrack::kITSin) continue;
269 t=new AliITStrackV2(*esd);
270 } catch (const Char_t *msg) {
271 Warning("Clusters2Tracks",msg);
275 if (TMath::Abs(t->GetD(GetX(),GetY()))>4) {
280 if (CorrectForDeadZoneMaterial(t)!=0) {
281 Warning("Clusters2Tracks",
282 "failed to correct for the material in the dead zone !\n");
286 itsTracks.AddLast(t);
288 } /* End Read ESD tracks */
291 Int_t nentr=itsTracks.GetEntriesFast();
294 for (fPass=0; fPass<2; fPass++) {
295 Int_t &constraint=fConstraint[fPass]; if (constraint<0) continue;
296 for (Int_t i=0; i<nentr; i++) {
297 AliITStrackV2 *t=(AliITStrackV2*)itsTracks.UncheckedAt(i);
298 if (t==0) continue; //this track has been already tracked
299 Int_t tpcLabel=t->GetLabel(); //save the TPC track label
301 ResetTrackToFollow(*t);
304 for (FollowProlongation(); fI<kMaxLayer; fI++) {
305 while (TakeNextProlongation()) FollowProlongation();
308 if (fBestTrack.GetNumberOfClusters() == 0) continue;
310 if (fConstraint[fPass]) {
311 ResetTrackToFollow(*t);
312 if (!RefitAt(3.7, &fTrackToFollow, &fBestTrack)) continue;
316 fBestTrack.SetLabel(tpcLabel);
317 fBestTrack.CookdEdx();
318 CookLabel(&fBestTrack,0.); //For comparison only
319 fBestTrack.UpdateESDtrack(AliESDtrack::kITSin);
320 UseClusters(&fBestTrack);
321 delete itsTracks.RemoveAt(i);
328 Info("Clusters2Tracks","Number of prolonged tracks: %d\n",ntrk);
333 Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
334 //--------------------------------------------------------------------
335 // This functions propagates reconstructed ITS tracks back
336 // The clusters must be loaded !
337 //--------------------------------------------------------------------
338 Int_t nentr=event->GetNumberOfTracks();
339 Info("PropagateBack", "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::kITSin)==0) continue;
346 if (esd->GetStatus()&AliESDtrack::kITSout) continue;
350 t=new AliITStrackV2(*esd);
351 } catch (const Char_t *msg) {
352 Warning("PropagateBack",msg);
357 ResetTrackToFollow(*t);
359 // propagete to vertex [SR, GSI 17.02.2003]
360 // Start Time measurement [SR, GSI 17.02.2003], corrected by I.Belikov
361 if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {
362 if (fTrackToFollow.PropagateToVertex(event->GetVertex())) {
363 fTrackToFollow.StartTimeIntegral();
365 fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
368 fTrackToFollow.ResetCovariance(10.); fTrackToFollow.ResetClusters();
369 if (RefitAt(49.,&fTrackToFollow,t)) {
370 if (CorrectForDeadZoneMaterial(&fTrackToFollow)!=0) {
371 Warning("PropagateBack",
372 "failed to correct for the material in the dead zone !\n");
376 fTrackToFollow.SetLabel(t->GetLabel());
377 //fTrackToFollow.CookdEdx();
378 CookLabel(&fTrackToFollow,0.); //For comparison only
379 fTrackToFollow.UpdateESDtrack(AliESDtrack::kITSout);
380 UseClusters(&fTrackToFollow);
386 Info("PropagateBack","Number of back propagated ITS tracks: %d\n",ntrk);
391 Int_t AliITStrackerV2::RefitInward(AliESD *event) {
392 //--------------------------------------------------------------------
393 // This functions refits ITS tracks using the
394 // "inward propagated" TPC tracks
395 // The clusters must be loaded !
396 //--------------------------------------------------------------------
397 Int_t nentr=event->GetNumberOfTracks();
398 Info("RefitInward", "Number of ESD tracks: %d\n", nentr);
401 for (Int_t i=0; i<nentr; i++) {
402 AliESDtrack *esd=event->GetTrack(i);
404 if ((esd->GetStatus()&AliESDtrack::kITSout) == 0) continue;
405 if (esd->GetStatus()&AliESDtrack::kITSrefit) continue;
406 if (esd->GetStatus()&AliESDtrack::kTPCout)
407 if ((esd->GetStatus()&AliESDtrack::kTPCrefit)==0) continue;
411 t=new AliITStrackV2(*esd);
412 } catch (const Char_t *msg) {
413 Warning("RefitInward",msg);
418 if (CorrectForDeadZoneMaterial(t)!=0) {
419 Warning("RefitInward",
420 "failed to correct for the material in the dead zone !\n");
425 ResetTrackToFollow(*t);
426 fTrackToFollow.ResetClusters();
429 if (RefitAt(3.7, &fTrackToFollow, t, kTRUE)) {
430 fTrackToFollow.SetLabel(t->GetLabel());
431 fTrackToFollow.CookdEdx();
432 CookLabel(&fTrackToFollow,0.); //For comparison only
434 if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {//The beam pipe
435 AliESDtrack *esdTrack =fTrackToFollow.GetESDtrack();
436 esdTrack->UpdateTrackParams(&fTrackToFollow,AliESDtrack::kITSrefit);
437 Float_t r[3]={0.,0.,0.};
439 esdTrack->RelateToVertex(event->GetVertex(),GetBz(r),maxD);
446 Info("RefitInward","Number of refitted tracks: %d\n",ntrk);
451 AliCluster *AliITStrackerV2::GetCluster(Int_t index) const {
452 //--------------------------------------------------------------------
453 // Return pointer to a given cluster
454 //--------------------------------------------------------------------
455 Int_t l=(index & 0xf0000000) >> 28;
456 Int_t c=(index & 0x0fffffff) >> 00;
457 return fgLayers[l].GetCluster(c);
461 void AliITStrackerV2::FollowProlongation() {
462 //--------------------------------------------------------------------
463 //This function finds a track prolongation
464 //--------------------------------------------------------------------
465 while (fI>fLastLayerToTrackTo) {
468 AliITSlayer &layer=fgLayers[i];
469 AliITStrackV2 &track=fTracks[i];
471 Double_t r=layer.GetR();
474 Double_t rs=0.5*(fgLayers[i+1].GetR() + r);
475 Double_t d=0.0034, x0=38.6;
476 if (i==1) {rs=9.; d=0.0097; x0=42;}
477 if (!fTrackToFollow.PropagateTo(rs,d,x0)) {
478 //Warning("FollowProlongation","propagation failed !\n");
485 if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z)) {
486 //Warning("FollowProlongation","failed to estimate track !\n");
489 Double_t phi=TMath::ATan2(y,x);
491 Int_t idet=layer.FindDetectorIndex(phi,z);
493 //Warning("FollowProlongation","failed to find a detector !\n");
497 //propagate to the intersection
498 const AliITSdetector &det=layer.GetDetector(idet);
500 if (!fTrackToFollow.Propagate(phi,det.GetR())) {
501 //Warning("FollowProlongation","propagation failed !\n");
504 fTrackToFollow.SetDetectorIndex(idet);
506 //Select possible prolongations and store the current track estimation
507 track.~AliITStrackV2(); new(&track) AliITStrackV2(fTrackToFollow);
508 Double_t dz=7*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[i]);
509 Double_t dy=7*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[i]);
510 Double_t road=layer.GetRoad();
511 if (dz*dy>road*road) {
512 Double_t dd=TMath::Sqrt(dz*dy), scz=dz/dd, scy=dy/dd;
513 dz=road*scz; dy=road*scy;
516 //Double_t dz=4*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[i]);
517 if (dz < 0.5*TMath::Abs(track.GetTgl())) dz=0.5*TMath::Abs(track.GetTgl());
519 //Warning("FollowProlongation","too broad road in Z !\n");
523 if (TMath::Abs(fTrackToFollow.GetZ()-GetZ()) > r+dz) return;
525 //Double_t dy=4*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[i]);
526 if (dy < 0.5*TMath::Abs(track.GetSnp())) dy=0.5*TMath::Abs(track.GetSnp());
528 //Warning("FollowProlongation","too broad road in Y !\n");
534 Double_t zmin=track.GetZ() - dz;
535 Double_t zmax=track.GetZ() + dz;
536 Double_t ymin=track.GetY() + r*phi - dy;
537 Double_t ymax=track.GetY() + r*phi + dy;
538 if (layer.SelectClusters(zmin,zmax,ymin,ymax)==0)
539 if (fLayersNotToSkip[fI]) return;
541 if (!TakeNextProlongation())
542 if (fLayersNotToSkip[fI]) return;
546 //deal with the best track
547 Int_t ncl=fTrackToFollow.GetNumberOfClusters();
548 Int_t nclb=fBestTrack.GetNumberOfClusters();
551 Double_t chi2=fTrackToFollow.GetChi2();
552 if (chi2/ncl < kChi2PerCluster) {
553 if (ncl > nclb || chi2 < fBestTrack.GetChi2()) {
561 Int_t AliITStrackerV2::TakeNextProlongation() {
562 //--------------------------------------------------------------------
563 // This function takes another track prolongation
565 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
566 //--------------------------------------------------------------------
567 AliITSlayer &layer=fgLayers[fI];
568 ResetTrackToFollow(fTracks[fI]);
570 Double_t dz=7*TMath::Sqrt(fTrackToFollow.GetSigmaZ2() + kSigmaZ2[fI]);
571 Double_t dy=7*TMath::Sqrt(fTrackToFollow.GetSigmaY2() + kSigmaY2[fI]);
572 Double_t road=layer.GetRoad();
573 if (dz*dy>road*road) {
574 Double_t dd=TMath::Sqrt(dz*dy), scz=dz/dd, scy=dy/dd;
575 dz=road*scz; dy=road*scy;
578 const AliITSRecPoint *c=0; Int_t ci=-1;
579 const AliITSRecPoint *cc=0; Int_t cci=-1;
580 Double_t chi2=kMaxChi2;
581 while ((c=layer.GetNextCluster(ci))!=0) {
582 Int_t idet=c->GetDetectorIndex();
584 if (fTrackToFollow.GetDetectorIndex()!=idet) {
585 const AliITSdetector &det=layer.GetDetector(idet);
586 ResetTrackToFollow(fTracks[fI]);
587 if (!fTrackToFollow.Propagate(det.GetPhi(),det.GetR())) {
588 //Warning("TakeNextProlongation","propagation failed !\n");
591 fTrackToFollow.SetDetectorIndex(idet);
592 if (TMath::Abs(fTrackToFollow.GetZ()-GetZ())>layer.GetR()+dz) continue;
595 if (TMath::Abs(fTrackToFollow.GetZ() - c->GetZ()) > dz) continue;
596 if (TMath::Abs(fTrackToFollow.GetY() - c->GetY()) > dy) continue;
598 Double_t ch2=fTrackToFollow.GetPredictedChi2(c);
599 if (ch2 > chi2) continue;
607 if (!fTrackToFollow.PropagateTo(cc->GetX(),0.,0.)) return 0; // Alignment
608 if (!fTrackToFollow.Update(cc,chi2,(fI<<28)+cci)) {
609 //Warning("TakeNextProlongation","filtering failed !\n");
613 if (fTrackToFollow.GetNumberOfClusters()>1)
614 if (TMath::Abs(fTrackToFollow.GetD(GetX(),GetY()))>4) return 0;
617 SetSampledEdx(cc->GetQ(),fTrackToFollow.GetNumberOfClusters()-1); //b.b.
621 Double_t d=layer.GetThickness(fTrackToFollow.GetY(),fTrackToFollow.GetZ(),x0);
622 fTrackToFollow.CorrectForMaterial(d,x0);
625 if (fConstraint[fPass]) {
626 Double_t d=GetEffectiveThickness(0,0); //Think of this !!!!
627 Double_t xyz[]={GetX(),GetY(),GetZ()};
628 Double_t ers[]={GetSigmaX(),GetSigmaY(),GetSigmaZ()};
629 fTrackToFollow.Improve(d,xyz,ers);
636 AliITStrackerV2::AliITSlayer::AliITSlayer():
644 fRoad(2*fR*TMath::Sqrt(3.14/1.)) //assuming that there's only one cluster
646 //--------------------------------------------------------------------
647 //default AliITSlayer constructor
648 //--------------------------------------------------------------------
650 for (Int_t i=0; i<kNsector; i++) fN[i]=0;
654 AliITStrackerV2::AliITSlayer::
655 AliITSlayer(Double_t r,Double_t p,Double_t z,Int_t nl,Int_t nd):
661 fDetectors(new AliITSdetector[nl*nd]),
663 fRoad(2*r*TMath::Sqrt(3.14/1.)) //assuming that there's only one cluster
665 //--------------------------------------------------------------------
666 //main AliITSlayer constructor
667 //--------------------------------------------------------------------
669 for (Int_t i=0; i<kNsector; i++) fN[i]=0;
671 for (Int_t i=0; i<kMaxClusterPerLayer; i++) fClusters[i]=0;
675 AliITStrackerV2::AliITSlayer::~AliITSlayer() {
676 //--------------------------------------------------------------------
677 // AliITSlayer destructor
678 //--------------------------------------------------------------------
683 void AliITStrackerV2::AliITSlayer::ResetClusters() {
684 //--------------------------------------------------------------------
685 // This function removes loaded clusters
686 //--------------------------------------------------------------------
687 for (Int_t s=0; s<kNsector; s++) {
691 delete fClusters[s*kMaxClusterPerSector+n];
696 void AliITStrackerV2::AliITSlayer::ResetRoad() {
697 //--------------------------------------------------------------------
698 // This function calculates the road defined by the cluster density
699 //--------------------------------------------------------------------
701 for (Int_t s=0; s<kNsector; s++) {
704 if (TMath::Abs(fClusters[s*kMaxClusterPerSector+i]->GetZ())<fR) n++;
706 if (n>1) fRoad=2*fR*TMath::Sqrt(3.14/n);
709 Int_t AliITStrackerV2::AliITSlayer::InsertCluster(AliITSRecPoint *c) {
710 //--------------------------------------------------------------------
711 // This function inserts a cluster to this layer in increasing
712 // order of the cluster's fZ
713 //--------------------------------------------------------------------
714 Float_t circ=TMath::TwoPi()*fR;
715 Int_t sec=Int_t(kNsector*c->GetPhiR()/circ);
717 ::Error("InsertCluster","Wrong sector !\n");
721 if (n>=kMaxClusterPerSector) {
722 ::Error("InsertCluster","Too many clusters !\n");
725 if (n==0) fClusters[sec*kMaxClusterPerSector]=c;
727 Int_t i=FindClusterIndex(c->GetZ(),sec);
728 Int_t k=n-i+sec*kMaxClusterPerSector;
729 memmove(fClusters+i+1 ,fClusters+i,k*sizeof(AliITSRecPoint*));
737 AliITStrackerV2::AliITSlayer::FindClusterIndex(Float_t z,Int_t s) const {
738 //--------------------------------------------------------------------
739 // For the sector "s", this function returns the index of the first
740 // with its fZ >= "z".
741 //--------------------------------------------------------------------
743 if (nc==0) return kMaxClusterPerSector*s;
745 Int_t b=kMaxClusterPerSector*s;
746 if (z <= fClusters[b]->GetZ()) return b;
749 if (z > fClusters[e]->GetZ()) return e+1;
752 for (; b<e; m=(b+e)/2) {
753 if (z > fClusters[m]->GetZ()) b=m+1;
759 Int_t AliITStrackerV2::AliITSlayer::
760 SelectClusters(Float_t zmin,Float_t zmax,Float_t ymin, Float_t ymax) {
761 //--------------------------------------------------------------------
762 // This function selects clusters within the "window"
763 //--------------------------------------------------------------------
764 Float_t circ=fR*TMath::TwoPi();
766 if (ymin>circ) ymin-=circ; else if (ymin<0) ymin+=circ;
767 if (ymax>circ) ymax-=circ; else if (ymax<0) ymax+=circ;
769 Int_t i1=Int_t(kNsector*ymin/circ); if (i1==kNsector) i1--;
771 Float_t ym = (ymax<ymin) ? ymax+circ : ymax;
772 Int_t i=FindClusterIndex(zmin,i1), imax=i1*kMaxClusterPerSector+fN[i1];
773 for (; i<imax; i++) {
774 AliITSRecPoint *c=fClusters[i];
775 if (c->IsUsed()) continue;
776 if (c->GetZ()>zmax) break;
777 if (c->GetPhiR()<=ymin) continue;
778 if (c->GetPhiR()>ym) continue;
783 Int_t i2=Int_t(kNsector*ymax/circ); if (i2==kNsector) i2--;
784 if (i2==i1) return fNsel;
787 Float_t ym = (ymin>ymax) ? ymin-circ : ymin;
788 Int_t i=FindClusterIndex(zmin,i2), imax=i2*kMaxClusterPerSector+fN[i2];
789 for (; i<imax; i++) {
790 AliITSRecPoint *c=fClusters[i];
791 if (c->IsUsed()) continue;
792 if (c->GetZ()>zmax) break;
793 if (c->GetPhiR()<=ym) continue;
794 if (c->GetPhiR()>ymax) continue;
802 const AliITSRecPoint *AliITStrackerV2::AliITSlayer::GetNextCluster(Int_t &ci){
803 //--------------------------------------------------------------------
804 // This function returns clusters within the "window"
805 //--------------------------------------------------------------------
816 Int_t AliITStrackerV2::AliITSlayer::GetNumberOfClusters() const {
818 for (Int_t s=0; s<kNsector; s++) n+=fN[s];
823 AliITStrackerV2::AliITSlayer::FindDetectorIndex(Double_t phi,Double_t z)const {
824 //--------------------------------------------------------------------
825 //This function finds the detector crossed by the track
826 //--------------------------------------------------------------------
827 Double_t dphi=-(phi-fPhiOffset);
828 if (dphi < 0) dphi += 2*TMath::Pi();
829 else if (dphi >= 2*TMath::Pi()) dphi -= 2*TMath::Pi();
830 Int_t np=Int_t(dphi*fNladders*0.5/TMath::Pi()+0.5);
831 if (np>=fNladders) np-=fNladders;
832 if (np<0) np+=fNladders;
834 Double_t dz=fZOffset-z;
835 Int_t nz=Int_t(dz*(fNdetectors-1)*0.5/fZOffset+0.5);
836 if (nz>=fNdetectors) return -1;
839 return np*fNdetectors + nz;
843 AliITStrackerV2::AliITSlayer::GetThickness(Double_t y,Double_t z,Double_t &x0)
845 //--------------------------------------------------------------------
846 //This function returns the layer thickness at this point (units X0)
847 //--------------------------------------------------------------------
851 if (43<fR&&fR<45) { //SSD2
854 if (TMath::Abs(y-0.00)>3.40) d+=dd;
855 if (TMath::Abs(y-1.90)<0.45) {d+=(0.013-0.0034);}
856 if (TMath::Abs(y+1.90)<0.45) {d+=(0.013-0.0034);}
857 for (Int_t i=0; i<12; i++) {
858 if (TMath::Abs(z-3.9*(i+0.5))<0.15) {
859 if (TMath::Abs(y-0.00)>3.40) d+=dd;
863 if (TMath::Abs(z+3.9*(i+0.5))<0.15) {
864 if (TMath::Abs(y-0.00)>3.40) d+=dd;
868 if (TMath::Abs(z-3.4-3.9*i)<0.50) {d+=(0.016-0.0034); break;}
869 if (TMath::Abs(z+0.5+3.9*i)<0.50) {d+=(0.016-0.0034); break;}
872 if (37<fR&&fR<41) { //SSD1
875 if (TMath::Abs(y-0.00)>3.40) d+=dd;
876 if (TMath::Abs(y-1.90)<0.45) {d+=(0.013-0.0034);}
877 if (TMath::Abs(y+1.90)<0.45) {d+=(0.013-0.0034);}
878 for (Int_t i=0; i<11; i++) {
879 if (TMath::Abs(z-3.9*i)<0.15) {
880 if (TMath::Abs(y-0.00)>3.40) d+=dd;
884 if (TMath::Abs(z+3.9*i)<0.15) {
885 if (TMath::Abs(y-0.00)>3.40) d+=dd;
889 if (TMath::Abs(z-1.85-3.9*i)<0.50) {d+=(0.016-0.0034); break;}
890 if (TMath::Abs(z+2.05+3.9*i)<0.50) {d+=(0.016-0.0034); break;}
893 if (13<fR&&fR<26) { //SDD
896 if (TMath::Abs(y-0.00)>3.30) d+=dd;
898 if (TMath::Abs(y-1.80)<0.55) {
900 for (Int_t j=0; j<20; j++) {
901 if (TMath::Abs(z+0.7+1.47*j)<0.12) {d+=0.08; x0=9.; break;}
902 if (TMath::Abs(z-0.7-1.47*j)<0.12) {d+=0.08; x0=9.; break;}
905 if (TMath::Abs(y+1.80)<0.55) {
907 for (Int_t j=0; j<20; j++) {
908 if (TMath::Abs(z-0.7-1.47*j)<0.12) {d+=0.08; x0=9.; break;}
909 if (TMath::Abs(z+0.7+1.47*j)<0.12) {d+=0.08; x0=9.; break;}
913 for (Int_t i=0; i<4; i++) {
914 if (TMath::Abs(z-7.3*i)<0.60) {
916 if (TMath::Abs(y-0.00)>3.30) d+=dd;
919 if (TMath::Abs(z+7.3*i)<0.60) {
921 if (TMath::Abs(y-0.00)>3.30) d+=dd;
926 if (6<fR&&fR<8) { //SPD2
927 Double_t dd=0.0063; x0=21.5;
929 if (TMath::Abs(y-3.08)>0.5) d+=dd;
930 //if (TMath::Abs(y-3.08)>0.45) d+=dd;
931 if (TMath::Abs(y-3.03)<0.10) {d+=0.014;}
933 if (3<fR&&fR<5) { //SPD1
934 Double_t dd=0.0063; x0=21.5;
936 if (TMath::Abs(y+0.21)>0.6) d+=dd;
937 //if (TMath::Abs(y+0.21)>0.45) d+=dd;
938 if (TMath::Abs(y+0.10)<0.10) {d+=0.014;}
944 Double_t AliITStrackerV2::GetEffectiveThickness(Double_t y,Double_t z) const
946 //--------------------------------------------------------------------
947 //Returns the thickness between the current layer and the vertex (units X0)
948 //--------------------------------------------------------------------
949 Double_t d=0.0028*3*3; //beam pipe
952 Double_t xn=fgLayers[fI].GetR();
953 for (Int_t i=0; i<fI; i++) {
954 Double_t xi=fgLayers[i].GetR();
955 d+=fgLayers[i].GetThickness(y,z,x0)*xi*xi;
964 Double_t xi=0.5*(fgLayers[3].GetR()+fgLayers[4].GetR());
971 Bool_t AliITStrackerV2::RefitAt(Double_t xx,AliITStrackV2 *t,
972 const AliITStrackV2 *c, Bool_t extra) {
973 //--------------------------------------------------------------------
974 // This function refits the track "t" at the position "x" using
975 // the clusters from "c"
976 // If "extra"==kTRUE,
977 // the clusters from overlapped modules get attached to "t"
978 //--------------------------------------------------------------------
979 Int_t index[kMaxLayer];
981 for (k=0; k<kMaxLayer; k++) index[k]=-1;
982 Int_t nc=c->GetNumberOfClusters();
983 for (k=0; k<nc; k++) {
984 Int_t idx=c->GetClusterIndex(k),nl=(idx&0xf0000000)>>28;
988 Int_t from, to, step;
989 if (xx > t->GetX()) {
990 from=0; to=kMaxLayer;
993 from=kMaxLayer-1; to=-1;
997 for (Int_t i=from; i != to; i += step) {
998 AliITSlayer &layer=fgLayers[i];
999 Double_t r=layer.GetR();
1002 Double_t hI=i-0.5*step;
1003 if (TMath::Abs(hI-1.5)<0.01 || TMath::Abs(hI-3.5)<0.01) {
1004 Double_t rs=0.5*(fgLayers[i-step].GetR() + r);
1005 Double_t d=0.0034, x0=38.6;
1006 if (TMath::Abs(hI-1.5)<0.01) {rs=9.; d=0.0097; x0=42;}
1007 if (!t->PropagateTo(rs,-step*d,x0)) {
1013 // remember old position [SR, GSI 18.02.2003]
1014 Double_t oldX=0., oldY=0., oldZ=0.;
1015 if (t->IsStartedTimeIntegral() && step==1) {
1016 t->GetGlobalXYZat(t->GetX(),oldX,oldY,oldZ);
1021 if (!t->GetGlobalXYZat(r,x,y,z)) {
1024 Double_t phi=TMath::ATan2(y,x);
1025 Int_t idet=layer.FindDetectorIndex(phi,z);
1029 const AliITSdetector &det=layer.GetDetector(idet);
1031 if (!t->Propagate(phi,det.GetR())) {
1034 t->SetDetectorIndex(idet);
1036 const AliITSRecPoint *cl=0;
1037 Double_t maxchi2=kMaxChi2;
1041 const AliITSRecPoint *c=(AliITSRecPoint *)GetCluster(idx);
1042 if (idet != c->GetDetectorIndex()) {
1043 idet=c->GetDetectorIndex();
1044 const AliITSdetector &det=layer.GetDetector(idet);
1045 if (!t->Propagate(det.GetPhi(),det.GetR())) {
1048 t->SetDetectorIndex(idet);
1050 Double_t chi2=t->GetPredictedChi2(c);
1060 if (!t->PropagateTo(cl->GetX(),0.,0.)) return kFALSE; //Alignment
1061 if (!t->Update(cl,maxchi2,idx)) {
1064 t->SetSampledEdx(cl->GetQ(),t->GetNumberOfClusters()-1);
1069 Double_t d=layer.GetThickness(t->GetY(),t->GetZ(),x0);
1070 t->CorrectForMaterial(-step*d,x0);
1073 if (extra) { //search for extra clusters
1074 AliITStrackV2 tmp(*t);
1075 Double_t dz=4*TMath::Sqrt(tmp.GetSigmaZ2()+kSigmaZ2[i]);
1076 if (dz < 0.5*TMath::Abs(tmp.GetTgl())) dz=0.5*TMath::Abs(tmp.GetTgl());
1077 Double_t dy=4*TMath::Sqrt(t->GetSigmaY2()+kSigmaY2[i]);
1078 if (dy < 0.5*TMath::Abs(tmp.GetSnp())) dy=0.5*TMath::Abs(tmp.GetSnp());
1079 Double_t zmin=t->GetZ() - dz;
1080 Double_t zmax=t->GetZ() + dz;
1081 Double_t ymin=t->GetY() + phi*r - dy;
1082 Double_t ymax=t->GetY() + phi*r + dy;
1083 layer.SelectClusters(zmin,zmax,ymin,ymax);
1085 const AliITSRecPoint *c=0; Int_t ci=-1,cci=-1;
1086 Double_t maxchi2=1000.*kMaxChi2, tolerance=0.1;
1087 while ((c=layer.GetNextCluster(ci))!=0) {
1088 if (idet == c->GetDetectorIndex()) continue;
1090 const AliITSdetector &det=layer.GetDetector(c->GetDetectorIndex());
1092 if (!tmp.Propagate(det.GetPhi(),det.GetR())) continue;
1094 if (TMath::Abs(tmp.GetZ() - c->GetZ()) > tolerance) continue;
1095 if (TMath::Abs(tmp.GetY() - c->GetY()) > tolerance) continue;
1097 Double_t chi2=tmp.GetPredictedChi2(c);
1098 if (chi2<maxchi2) { maxchi2=chi2; cci=ci; }
1100 if (cci>=0) t->SetExtraCluster(i,(i<<28)+cci);
1103 // track time update [SR, GSI 17.02.2003]
1104 if (t->IsStartedTimeIntegral() && step==1) {
1105 Double_t newX, newY, newZ;
1106 t->GetGlobalXYZat(t->GetX(),newX,newY,newZ);
1107 Double_t dL2 = (oldX-newX)*(oldX-newX) + (oldY-newY)*(oldY-newY) +
1108 (oldZ-newZ)*(oldZ-newZ);
1109 t->AddTimeStep(TMath::Sqrt(dL2));
1115 if (!t->PropagateTo(xx,0.,0.)) return kFALSE;
1119 void AliITStrackerV2::UseClusters(const AliKalmanTrack *t, Int_t from) const {
1120 //--------------------------------------------------------------------
1121 // This function marks clusters assigned to the track
1122 //--------------------------------------------------------------------
1123 AliTracker::UseClusters(t,from);
1125 Int_t clusterIndex = t->GetClusterIndex(0);
1126 AliITSRecPoint *c= 0x0;
1128 if (clusterIndex>-1)
1129 c = (AliITSRecPoint *)GetCluster(clusterIndex);
1130 if (c && c->GetSigmaZ2()>0.1) c->UnUse();
1133 clusterIndex = t->GetClusterIndex(1);
1134 if (clusterIndex>-1)
1135 c=(AliITSRecPoint *)GetCluster(clusterIndex);
1136 if (c && c->GetSigmaZ2()>0.1) c->UnUse();