HMPID/AliHMPIDTracker.cxx

   1 #include "AliHMPIDTracker.h" //class header
   2 #include "AliHMPID.h"             //GetTrackPoint(),PropagateBack()
   3 #include "AliHMPIDCluster.h"      //GetTrackPoint(),PropagateBack()
   4 #include "AliHMPIDParam.h"        //GetTrackPoint(),PropagateBack()
   5 #include "AliHMPIDRecon.h"        //PropagateBack()
   6 #include <AliESD.h>              //PropagateBack()
   7 #include <AliRun.h>              //GetTrackPoint(),PropagateBack()
   8 #include <AliTrackPointArray.h>  //GetTrackPoint()
   9 #include <AliAlignObj.h>         //GetTrackPoint()
  10 ClassImp(AliHMPIDTracker)
  11 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  12 AliHMPIDTracker::AliHMPIDTracker():AliTracker()
  13 {
  14 // AliHMPIDTracker is created from AliReconstraction::Run() which invokes AliReconstraction::CreateTrackers()
  15 // which in turn invokes AliHMPIDReconstructor::CreateTracker().
  16 // Note that this is done just once per session before AliReconstruction::Run() goes to events loop.
  17 }
  18 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  19 Bool_t AliHMPIDTracker::GetTrackPoint(Int_t idx, AliTrackPoint& point) const
  20 {
  21 // Interface callback methode invoked from AliReconstruction::WriteAlignmentData() to get position of MIP cluster in MARS associated to a current track.
  22 // MIP cluster is reffered by index which is stored in AliESDtrack  ???????
  23 // Arguments: idx- cluster index which is stored by HMPID in AliESDtrack
  24 //            point- reference to the object where to store the point
  25 //   Returns: status of operation  if FALSE then AliReconstruction::WriteAlignmentData() do not store this point to array of points for current track.
  26   if(idx<0) return kFALSE; //no MIP cluster assigned to this track in PropagateBack()
  27   Int_t iCham=idx/1000000;
  28   Int_t iClu=idx%1000000;
  29   point.SetVolumeID(AliAlignObj::LayerToVolUID(AliAlignObj::kHMPID,iCham-1));//layer and chamber number
  30   AliHMPID *pRich=((AliHMPID*)gAlice->GetDetector("HMPID"));
  31   AliHMPIDCluster *pClu=(AliHMPIDCluster*)pRich->CluLst(iCham)->UncheckedAt(iClu);//get pointer to cluster
  32   Double_t mars[3];
  33   AliHMPIDParam::Instance()->Lors2Mars(iCham,pClu->X(),pClu->Y(),mars);
  34   point.SetXYZ(mars[0],mars[1],mars[2]);
  35   return kTRUE;
  36 }
  37 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  38 Int_t AliHMPIDTracker::LoadClusters(TTree *pCluTree)
  39 {
  40 // Interface callback methode invoked from AliReconstruction::RunTracking() to load HMPID clusters before PropagateBack() gets control
  41 // Arguments: pCluTree- pointer to clusters tree got by AliHMPIDLoader::LoadRecPoints("read") then AliHMPIDLoader::TreeR()
  42 //   Returns: error code (currently ignored in AliReconstruction::RunTraking())
  43   AliDebug(1,"Start.");  pCluTree->GetEntry(0);  AliDebug(1,"Stop."); return 0;
  44 }
  45 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  46 Int_t AliHMPIDTracker::PropagateBack(AliESD *pESD)
  47 {
  48 // Interface callback methode invoked by AliRecontruction::RunTracking() during tracking after TOF. It's done just once per event
  49 // Arguments: pESD - pointer to Event Summary Data class instance which contains a list of tracks
  50 //   Returns: error code, 0 if no errors
  51   Int_t iNtracks=pESD->GetNumberOfTracks();  AliDebug(1,Form("Start with %i tracks",iNtracks));
  52   AliHMPID *pRich=((AliHMPID*)gAlice->GetDetector("HMPID"));
  53   AliHMPIDRecon recon;                                                        //instance of reconstruction class, nothing important in ctor
  54
  55   AliHMPIDParam *pParam=AliHMPIDParam::Instance();
  56
  57   for(Int_t iTrk=0;iTrk<iNtracks;iTrk++){                                                        //ESD tracks loop
  58     AliESDtrack *pTrk = pESD->GetTrack(iTrk);                                                    //get next reconstructed track
  59
  60     Float_t xRa=0,yRa=0,xPc=0,yPc=0,th=0,ph=0;                                                   //track intersection point and angles, LORS
  61     Int_t iCh=-1;                                                                                //intersected chamber
  62     for(Int_t i=0;i<7;i++){                                                                      //chambers loop
  63       Double_t p1[3],n1[3]; pParam->Norm(i,n1); pParam->Lors2Mars(i,0,0,p1,AliHMPIDParam::kRad);  //point & norm  for RAD
  64       Double_t p2[3],n2[3]; pParam->Norm(i,n2); pParam->Lors2Mars(i,0,0,p2,AliHMPIDParam::kPc);   //point & norm  for PC
  65
  66       if(pTrk->Intersect(p1,n1,-GetBz())==kFALSE) continue;                                      //try to intersect track with the middle of radiator
  67       if(pTrk->Intersect(p2,n2,-GetBz())==kFALSE) continue;                                      //try to intersect track with PC
  68
  69       pParam->Mars2LorsVec(i,n1,th,ph);                                                          //track angles
  70       pParam->Mars2Lors   (i,p1,xRa,yRa);                                                        //TRKxRAD position
  71       pParam->Mars2Lors   (i,p2,xPc,yPc);                                                        //TRKxPC position
  72
  73       if(AliHMPIDDigit::IsInside(xPc,yPc)==kFALSE) continue;                                      //not in active area
  74       iCh=i;
  75       break;
  76     }//chambers loop
  77
  78     if(iCh==-1) continue;                                                                  //no intersection at all, go after next track
  79
  80     TClonesArray *pCluLst=pRich->CluLst(iCh);                                              //get clusters list for intersected chamber
  81
  82     Double_t    dMin=999;                                                                  //distance between track-PC intersection point and current cluster
  83     Int_t   iMip=-1;                                                                       //index of cluster nearest to intersection point
  84     for(Int_t iClu=0;iClu<pCluLst->GetEntries();iClu++){                                   //clusters loop for intersected chamber
  85       AliHMPIDCluster *pClu=(AliHMPIDCluster*)pCluLst->At(iClu);                             //get pointer to current cluster
  86       if(pClu->Q()<100) continue;                                                          //QDC is incompartible with mip, go after another one
  87
  88       Float_t dX=xPc-pClu->X();                                                            //distance between current cluster and intersection point
  89       Float_t dY=yPc-pClu->Y();
  90       Float_t d =TMath::Sqrt(dX*dX+dY*dY);
  91
  92       if( d < dMin) {iMip=iClu; dMin=d;}                                                   //current cluster is closer, overwrite data for min cluster
  93     }//clusters loop for intersected chamber
  94
  95                    pTrk->SetHMPIDtrk      (xPc,yPc,th,ph);                                  //store track info
  96     if(iMip==-1)  {pTrk->SetHMPIDsignal   (kMipQdcCut);  continue;}                         //no clusters with QDC more the threshold at all
  97
  98     AliHMPIDCluster *pMipClu=(AliHMPIDCluster*)pCluLst->At(iMip);                            //take mip cluster
  99
 100                    pTrk->SetHMPIDmip      (pMipClu->X(),pMipClu->Y(),pMipClu->Q());          //store mip info
 101     if(dMin>1)    {pTrk->SetHMPIDsignal   (kMipDistCut); continue;}                          //closest cluster with enough charge is still too far
 102                    pTrk->SetHMPIDcluIdx   (iCh,iMip);                                        //set mip cluster index
 103   recon.SetTrack(th,ph,xRa,yRa); Int_t iNphot=0;                                            //initialize track parameters
 104                    pTrk->SetHMPIDsignal   (recon.CkovAngle(pCluLst,iNphot));                 //search for Cerenkov angle for this track
 105                    pTrk->SetHMPIDchi2     (recon.CkovSigma2());                              //error squared
 106                    pTrk->SetHMPIDmip      (pMipClu->X(),pMipClu->Y(),pMipClu->Q(),iMip);     //info on mip cluster + n. phot.
 107  }//ESD tracks loop
 108   AliDebug(1,"Stop pattern recognition");
 109   return 0; // error code: 0=no error;
 110 }//PropagateBack()
 111 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++