RICH/AliRICHTracker.cxx

   1 #include "AliRICHTracker.h"
   2 #include <AliESD.h>
   3 #include <TVector3.h>
   4 #include <TTree.h>
   5 #include "AliRICH.h"
   6 #include "AliRICHHelix.h"
   7 #include <AliMagF.h>
   8 #include "AliRICHRecon.h"
   9 #include <AliStack.h>
  10 #include <TParticle.h>
  11 #include <TMath.h>
  12 ClassImp(AliRICHTracker)
  13 //__________________________________________________________________________________________________
  14 Int_t AliRICHTracker::PropagateBack(AliESD *pESD)
  15 {
  16   //invoked by AliRecontruction for RICH
  17   //if ESD doesn't contain tracks, try to reconstruct with particle from STACK
  18   //(this case is just to forsee a standalone RICH simulation
  19   TNtupleD *hn=0;
  20   AliDebug(1,"Start pattern recognition");
  21   if(pESD->GetNumberOfTracks()) RecWithESD(pESD);
  22   else
  23     RecWithStack(hn);
  24   AliDebug(1,"Stop pattern recognition");
  25
  26   return 0; // error code: 0=no error;
  27 } //pure virtual from AliTracker
  28 //__________________________________________________________________________________________________
  29 void AliRICHTracker::RecWithESD(AliESD *pESD)
  30 {
  31   //recontruction from ESD
  32   //
  33   Int_t iNtracks=pESD->GetNumberOfTracks();
  34   Double_t b=GetFieldMap()->SolenoidField()/10;// magnetic field in Tesla
  35   AliDebug(1,Form("Start with %i tracks in %f Tesla field",iNtracks,b));
  36   Double_t xb[3],pb[3];//tmp storage for track parameters
  37   TVector3 x0(0,0,0); TVector3 p0(0,0,0);//tmp storage for AliRICHHelix
  38
  39   AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
  40
  41   for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//ESD tracks loop
  42     AliESDtrack *pTrack = pESD->GetTrack(iTrackN);// get next reconstructed track
  43 //  if((pTrack->GetStatus()&AliESDtrack::kTOFout)==0) continue; //ignore tracks not recontructed by TOF
  44     pTrack->GetXYZ(xb);
  45     pTrack->GetPxPyPz(pb);
  46     Int_t status=pTrack->GetStatus()&AliESDtrack::kTOFout;//get running track parameters
  47     AliDebug(1,Form("Track %i pmod=%f mass=%f stat=%i",iTrackN,pTrack->GetP(),pTrack->GetMass(),status));
  48     x0.SetXYZ(xb[0],xb[1],xb[2]); p0.SetXYZ(xb[0],xb[1],xb[2]);
  49     AliRICHHelix helix(x0,p0,pTrack->GetSign(),b);
  50     Int_t iChamber=helix.RichIntersect(pRich->P());
  51     AliDebug(1,Form("intersection with %i chamber found",iChamber));
  52     if(!iChamber) continue;//intersection with no chamber found
  53
  54     Double_t distMip=9999; //min distance between clusters and track position on PC
  55     Int_t iMipId=0; //index of that min distance cluster
  56     for(Int_t iClusN=0;iClusN<pRich->Clusters(iChamber)->GetEntries();iClusN++){//clusters loop for intersected chamber
  57       AliRICHcluster *pClus=(AliRICHcluster*)pRich->Clusters(iChamber)->UncheckedAt(iClusN);//get pointer to current cluster
  58       Double_t distCurrent=pClus->DistTo(helix.PosPc());//ditance between current cluster and helix intersection with PC
  59       if(distCurrent<distMip){distMip=distCurrent;iMipId=iClusN;}//find cluster nearest to the track
  60
  61       AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
  62                                                                     helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
  63     }////clusters loop for intersected chamber
  64
  65     AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
  66
  67     AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId);
  68     Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
  69     AliDebug(1,Form("FINAL Theta Cerenkov=%f",thetaCerenkov));
  70     pTrack->SetRICHsignal(thetaCerenkov);
  71
  72 //    Double_t richPID[5]={0.2,0.2,0.2,0.2,0.2}; //start with equal probs for (e,mu,pi,k,p)
  73 //    CalcProb(thetaCerenkov,p0.Mag(),richPID);
  74 //    pTrack->SetRICHpid(richPID);
  75
  76   }//ESD tracks loop
  77   AliDebug(1,"Stop.");
  78 } //RecWithESD
  79 //__________________________________________________________________________________________________
  80 void AliRICHTracker::RecWithStack(TNtupleD *hn)
  81 {
  82   // reconstruction for particles from STACK
  83   //
  84   AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
  85
  86 //  pRich->GetLoader()->GetRunLoader()->LoadHeader();
  87   pRich->GetLoader()->GetRunLoader()->LoadKinematics();
  88   AliStack *pStack =   pRich->GetLoader()->GetRunLoader()->Stack();
  89   Int_t iNtracks=pStack->GetNtrack();
  90   AliDebug(1,Form(" Start reconstruction with %i track(s) from Stack",iNtracks));
  91
  92   Double_t hnvec[12];
  93
  94   Double_t b=GetFieldMap()->SolenoidField()/10;// magnetic field in Tesla
  95   AliDebug(1,Form("Start with simulated %i tracks in %f Tesla field",iNtracks,b));
  96   TVector3 x0(0,0,0); TVector3 p0(0,0,0);//tmp storage for AliRICHHelix
  97
  98
  99   if(pRich->GetLoader()->LoadRecPoints()) {AliDebug(1,Form("No clusters found in RICH"));return;}
 100   pRich->GetLoader()->TreeR()->GetEntry(0);
 101
 102   for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//ESD tracks loop
 103     TParticle *pParticle = pStack->Particle(iTrackN);
 104     AliDebug(1,Form("Track %i is a %s with charge %i and momentum %f",
 105             iTrackN,pParticle->GetPDG()->GetName(),Int_t(pParticle->GetPDG()->Charge()),pParticle->P()));
 106 //    if(pParticle->GetMother(0)!=-1) continue; //consider only primaries
 107     if(pParticle->GetPDG()->Charge()==0||TMath::Abs(Int_t(pParticle->GetPDG()->Charge()))!=3) continue; //to avoid photons from stack...
 108     hnvec[0]=pParticle->P();
 109     hnvec[1]=pParticle->GetPDG()->Charge();
 110     hnvec[2]=pParticle->Theta();
 111     hnvec[3]=pParticle->Phi();
 112     p0.SetMagThetaPhi(pParticle->P(),pParticle->Theta(),pParticle->Phi());
 113     x0.SetXYZ(pParticle->Vx(),pParticle->Vy(),pParticle->Vz());
 114     AliRICHHelix helix(x0,p0,TMath::Sign(1,(Int_t)pParticle->GetPDG()->Charge()),b);
 115     Int_t iChamber=helix.RichIntersect(pRich->P());
 116     AliDebug(1,Form("intersection with %i chamber found",iChamber));
 117     if(!iChamber) continue;// no intersection with RICH found
 118     hnvec[4]=helix.PosPc().X();
 119     hnvec[5]=helix.PosPc().Y();
 120     Double_t distMip=9999;   //min distance between clusters and track position on PC
 121     Double_t mipX=kBad;      //min distance between clusters and track position on PC
 122     Double_t mipY=kBad;      //min distance between clusters and track position on PC
 123     Double_t chargeMip=kBad; // charge MIP to find
 124     Int_t iMipId=kBad;       //index of that min distance cluster
 125     for(Int_t iClusN=0;iClusN<pRich->Clusters(iChamber)->GetEntries();iClusN++){//clusters loop for intersected chamber
 126       AliRICHcluster *pClus=(AliRICHcluster*)pRich->Clusters(iChamber)->UncheckedAt(iClusN);//get pointer to current cluster
 127       Double_t distCurrent=pClus->DistTo(helix.PosPc());//ditance between current cluster and helix intersection with PC
 128       if(distCurrent<distMip){distMip=distCurrent;mipX=pClus->X();
 129                                                   mipY=pClus->Y();
 130                                                   chargeMip=pClus->Q();iMipId=1000000*iChamber+iClusN;}//find cluster nearest to the track
 131
 132       AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
 133                                                                     helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
 134     }////clusters loop for intersected chamber
 135
 136     AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
 137     hnvec[6]=mipX;hnvec[7]=mipY;
 138     hnvec[8]=chargeMip;
 139     AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId);
 140     Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
 141     hnvec[9]=thetaCerenkov;
 142     hnvec[10]=recon.GetHoughPhotons();
 143     hnvec[11]=(Double_t)iMipId;
 144     if(hn) hn->Fill(hnvec);
 145     AliDebug(1,Form("FINAL Theta Cerenkov=%f",thetaCerenkov));
 146 //    pTrack->SetRICHsignal(thetaCerenkov);
 147
 148 //    Double_t richPID[5]={0.2,0.2,0.2,0.2,0.2}; //start with equal probs for (e,mu,pi,k,p)
 149 //    CalcProb(thetaCerenkov,p0.Mag(),richPID);
 150
 151   }//ESD tracks loop
 152
 153  pRich->GetLoader()->UnloadRecPoints();
 154
 155   AliDebug(1,"Stop.");
 156 } //RecWithStack
 157
 158 Int_t AliRICHTracker::LoadClusters(TTree *pTree)
 159 {
 160 // Load clusters for RICH
 161   AliDebug(1,"Start.");  pTree->GetEntry(0);  AliDebug(1,"Stop."); return 0;
 162 }
 163
 164 //__________________________________________________________________________________________________
 165 void AliRICHTracker::CalcProb(Double_t thetaCer,Double_t pmod, Double_t *richPID)
 166 {
 167 //
 168   Double_t height[AliPID::kSPECIES];Double_t totalHeight=0;
 169   for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++){
 170     Double_t mass = AliPID::ParticleMass(iPart);
 171     Double_t refIndex=AliRICHParam::IndOfRefC6F14(6.755);
 172     Double_t cosThetaTh = TMath::Sqrt(mass*mass+pmod*pmod)/(refIndex*pmod);
 173     if(cosThetaTh>=1) {break;}
 174     Double_t thetaTh = TMath::ACos(cosThetaTh);
 175     Double_t sinThetaThNorm = TMath::Sin(thetaTh)/TMath::Sqrt(1-1/(refIndex*refIndex));
 176     Double_t sigmaThetaTh = (0.014*(1/sinThetaThNorm-1) + 0.0043)*1.25;
 177     height[iPart] = TMath::Gaus(thetaCer,thetaTh,sigmaThetaTh);
 178     totalHeight +=height[iPart];
 179   }
 180   for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++) richPID[iPart] = height[iPart]/totalHeight;
 181 }//CalcProb