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 <TDatabasePDG.h>
  12 #include <TMath.h>
  13 ClassImp(AliRICHTracker)
  14 //__________________________________________________________________________________________________
  15 Int_t AliRICHTracker::PropagateBack(AliESD *pESD)
  16 {
  17   //invoked by AliRecontruction for RICH
  18   //if ESD doesn't contain tracks, try to reconstruct with particle from STACK
  19   //(this case is just to forsee a standalone RICH simulation
  20   TNtupleD *hn=0;
  21   AliDebug(1,"Start pattern recognition");
  22   if(pESD->GetNumberOfTracks()) RecWithESD(pESD);
  23   else
  24     RecWithStack(hn);
  25   AliDebug(1,"Stop pattern recognition");
  26
  27   return 0; // error code: 0=no error;
  28 } //pure virtual from AliTracker
  29 //__________________________________________________________________________________________________
  30 void AliRICHTracker::RecWithESD(AliESD *pESD)
  31 {
  32   //recontruction from ESD
  33   //
  34   Int_t iNtracks=pESD->GetNumberOfTracks();
  35   Double_t b=GetFieldMap()->SolenoidField()/10;// magnetic field in Tesla
  36   AliDebug(1,Form("Start with %i tracks in %f Tesla field",iNtracks,b));
  37   Double_t xb[3],pb[3];//tmp storage for track parameters
  38   TVector3 x0(0,0,0); TVector3 p0(0,0,0);//tmp storage for AliRICHHelix
  39
  40   AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
  41
  42   for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//ESD tracks loop
  43     AliESDtrack *pTrack = pESD->GetTrack(iTrackN);// get next reconstructed track
  44 //  if((pTrack->GetStatus()&AliESDtrack::kTOFout)==0) continue; //ignore tracks not recontructed by TOF
  45     pTrack->GetXYZ(xb);
  46     pTrack->GetPxPyPz(pb);
  47     Int_t status=pTrack->GetStatus()&AliESDtrack::kTOFout;//get running track parameters
  48     AliDebug(1,Form("Track %i pmod=%f mass=%f stat=%i",iTrackN,pTrack->GetP(),pTrack->GetMass(),status));
  49     x0.SetXYZ(xb[0],xb[1],xb[2]); p0.SetXYZ(xb[0],xb[1],xb[2]);
  50     AliRICHHelix helix(x0,p0,pTrack->GetSign(),b);
  51     Int_t iChamber=helix.RichIntersect(pRich->P());
  52     AliDebug(1,Form("intersection with %i chamber found",iChamber));
  53     if(!iChamber) continue;//intersection with no chamber found
  54
  55     Double_t distMip=9999; //min distance between clusters and track position on PC
  56     Int_t iMipId=0; //index of that min distance cluster
  57     for(Int_t iClusN=0;iClusN<pRich->Clusters(iChamber)->GetEntries();iClusN++){//clusters loop for intersected chamber
  58       AliRICHcluster *pClus=(AliRICHcluster*)pRich->Clusters(iChamber)->UncheckedAt(iClusN);//get pointer to current cluster
  59       Double_t distCurrent=pClus->DistTo(helix.PosPc());//ditance between current cluster and helix intersection with PC
  60       if(distCurrent<distMip){distMip=distCurrent;iMipId=iClusN;}//find cluster nearest to the track
  61
  62       AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
  63                                                                     helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
  64     }////clusters loop for intersected chamber
  65
  66     AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
  67
  68     AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId);
  69     Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
  70     AliDebug(1,Form("FINAL Theta Cerenkov=%f",thetaCerenkov));
  71     pTrack->SetRICHsignal(thetaCerenkov);
  72
  73 //    Double_t richPID[5]={0.2,0.2,0.2,0.2,0.2}; //start with equal probs for (e,mu,pi,k,p)
  74 //    CalcProb(thetaCerenkov,p0.Mag(),richPID);
  75 //    pTrack->SetRICHpid(richPID);
  76
  77   }//ESD tracks loop
  78   AliDebug(1,"Stop.");
  79 } //RecWithESD
  80 //__________________________________________________________________________________________________
  81 void AliRICHTracker::RecWithStack(TNtupleD *hn)
  82 {
  83   // reconstruction for particles from STACK
  84   //
  85   AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
  86
  87 //  pRich->GetLoader()->GetRunLoader()->LoadHeader();
  88   pRich->GetLoader()->GetRunLoader()->LoadKinematics();
  89   AliStack *pStack =   pRich->GetLoader()->GetRunLoader()->Stack();
  90   Int_t iNtracks=pStack->GetNtrack();
  91   AliDebug(1,Form(" Start reconstruction with %i track(s) from Stack",iNtracks));
  92
  93   Double_t hnvec[12];
  94
  95   Double_t b=GetFieldMap()->SolenoidField()/10;// magnetic field in Tesla
  96   AliDebug(1,Form("Start with simulated %i tracks in %f Tesla field",iNtracks,b));
  97   TVector3 x0(0,0,0); TVector3 p0(0,0,0);//tmp storage for AliRICHHelix
  98
  99
 100   if(pRich->GetLoader()->LoadRecPoints()) {AliDebug(1,Form("No clusters found in RICH"));return;}
 101   pRich->GetLoader()->TreeR()->GetEntry(0);
 102
 103   for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//ESD tracks loop
 104     TParticle *pParticle = pStack->Particle(iTrackN);
 105     AliDebug(1,Form("Track %i is a %s with charge %i and momentum %f",
 106             iTrackN,pParticle->GetPDG()->GetName(),Int_t(pParticle->GetPDG()->Charge()),pParticle->P()));
 107 //    if(pParticle->GetMother(0)!=-1) continue; //consider only primaries
 108     if(pParticle->GetPDG()->Charge()==0||TMath::Abs(Int_t(pParticle->GetPDG()->Charge()))!=3) continue; //to avoid photons from stack...
 109     hnvec[0]=pParticle->P();
 110     hnvec[1]=pParticle->GetPDG()->Charge();
 111     hnvec[2]=pParticle->Theta();
 112     hnvec[3]=pParticle->Phi();
 113     p0.SetMagThetaPhi(pParticle->P(),pParticle->Theta(),pParticle->Phi());
 114     x0.SetXYZ(pParticle->Vx(),pParticle->Vy(),pParticle->Vz());
 115     AliRICHHelix helix(x0,p0,TMath::Sign(1,(Int_t)pParticle->GetPDG()->Charge()),b);
 116     Int_t iChamber=helix.RichIntersect(pRich->P());
 117     AliDebug(1,Form("intersection with %i chamber found",iChamber));
 118     if(!iChamber) continue;// no intersection with RICH found
 119     hnvec[4]=helix.PosPc().X();
 120     hnvec[5]=helix.PosPc().Y();
 121     Double_t distMip=9999;   //min distance between clusters and track position on PC
 122     Double_t mipX=kBad;      //min distance between clusters and track position on PC
 123     Double_t mipY=kBad;      //min distance between clusters and track position on PC
 124     Double_t chargeMip=kBad; // charge MIP to find
 125     Int_t iMipId=kBad;       //index of that min distance cluster
 126     for(Int_t iClusN=0;iClusN<pRich->Clusters(iChamber)->GetEntries();iClusN++){//clusters loop for intersected chamber
 127       AliRICHcluster *pClus=(AliRICHcluster*)pRich->Clusters(iChamber)->UncheckedAt(iClusN);//get pointer to current cluster
 128       Double_t distCurrent=pClus->DistTo(helix.PosPc());//ditance between current cluster and helix intersection with PC
 129       if(distCurrent<distMip){distMip=distCurrent;mipX=pClus->X();
 130                                                   mipY=pClus->Y();
 131                                                   chargeMip=pClus->Q();iMipId=1000000*iChamber+iClusN;}//find cluster nearest to the track
 132
 133       AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
 134                                                                     helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
 135     }////clusters loop for intersected chamber
 136
 137     AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
 138     hnvec[6]=mipX;hnvec[7]=mipY;
 139     hnvec[8]=chargeMip;
 140     AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId);
 141     Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
 142     hnvec[9]=thetaCerenkov;
 143     hnvec[10]=recon.GetHoughPhotons();
 144     hnvec[11]=(Double_t)iMipId;
 145     if(hn) hn->Fill(hnvec);
 146     AliDebug(1,Form("FINAL Theta Cerenkov=%f",thetaCerenkov));
 147 //    pTrack->SetRICHsignal(thetaCerenkov);
 148
 149 //    Double_t richPID[5]={0.2,0.2,0.2,0.2,0.2}; //start with equal probs for (e,mu,pi,k,p)
 150 //    CalcProb(thetaCerenkov,p0.Mag(),richPID);
 151
 152   }//ESD tracks loop
 153
 154  pRich->GetLoader()->UnloadRecPoints();
 155
 156   AliDebug(1,"Stop.");
 157 } //RecWithStack
 158
 159 Int_t AliRICHTracker::LoadClusters(TTree *pTree)
 160 {
 161 // Load clusters for RICH
 162   AliDebug(1,"Start.");  pTree->GetEntry(0);  AliDebug(1,"Stop."); return 0;
 163 }
 164
 165 //__________________________________________________________________________________________________
 166 void AliRICHTracker::CalcProb(Double_t thetaCer,Double_t pmod, Double_t *richPID)
 167 {
 168 //
 169   Double_t height[5];Double_t totalHeight=0;
 170   Int_t code[5]={kElectron,kMuonPlus,kPiPlus,kKPlus,kProton};
 171   TDatabasePDG *db = new TDatabasePDG();
 172   for(Int_t iPart=0;iPart<4;iPart++){
 173     Double_t mass = db->GetParticle(code[iPart])->Mass();
 174     Double_t refIndex=AliRICHParam::IndOfRefC6F14(6.755);
 175     Double_t cosThetaTh = TMath::Sqrt(mass*mass+pmod*pmod)/(refIndex*pmod);
 176     if(cosThetaTh>=1) {break;}
 177     Double_t thetaTh = TMath::ACos(cosThetaTh);
 178     Double_t sinThetaThNorm = TMath::Sin(thetaTh)/TMath::Sqrt(1-1/(refIndex*refIndex));
 179     Double_t sigmaThetaTh = (0.014*(1/sinThetaThNorm-1) + 0.0043)*1.25;
 180     height[iPart] = TMath::Gaus(thetaCer,thetaTh,sigmaThetaTh);
 181     totalHeight +=height[iPart];
 182   }
 183   for(Int_t iPart=0;iPart<5;iPart++) richPID[iPart] = height[iPart]/totalHeight;
 184 }//CalcProb