Forseen the possibility to have RICH reconstruction from Stack (useful for debug...
[u/mrichter/AliRoot.git] / 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   
21   AliDebug(1,"Start pattern recognition");
22   if(pESD->GetNumberOfTracks()) RecWithESD(pESD);
23   else
24     RecWithStack();
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()
82 {
83   // reconstruction for particles from STACK
84   //
85   AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
86   
87   pRich->GetLoader()->GetRunLoader()->LoadHeader();pRich->GetLoader()->GetRunLoader()->LoadKinematics();
88   AliStack *pStack =   pRich->GetLoader()->GetRunLoader()->Stack();
89   Int_t iNtracks=pStack->GetNtrack();
90
91   Double_t b=GetFieldMap()->SolenoidField()/10;// magnetic field in Tesla
92   AliDebug(1,Form("Start with simulated %i tracks in %f Tesla field",iNtracks,b));
93   TVector3 x0(0,0,0); TVector3 p0(0,0,0);//tmp storage for AliRICHHelix
94   
95
96   for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//ESD tracks loop
97     TParticle *pParticle = pStack->Particle(iTrackN);
98     p0.SetMagThetaPhi(pParticle->P(),pParticle->Theta(),pParticle->Phi());
99     x0.SetXYZ(pParticle->Vx(),pParticle->Vy(),pParticle->Vz());
100     AliRICHHelix helix(x0,p0,Int_t(pParticle->GetPDG()->Charge()/3+0.1),b);   
101     Int_t iChamber=helix.RichIntersect(pRich->P());        
102     AliDebug(1,Form("intersection with %i chamber found",iChamber));
103     if(!iChamber) continue;//intersection with no chamber found
104     
105     Double_t distMip=9999; //min distance between clusters and track position on PC 
106     Int_t iMipId=0; //index of that min distance cluster 
107     for(Int_t iClusN=0;iClusN<pRich->Clusters(iChamber)->GetEntries();iClusN++){//clusters loop for intersected chamber
108       AliRICHcluster *pClus=(AliRICHcluster*)pRich->Clusters(iChamber)->UncheckedAt(iClusN);//get pointer to current cluster
109       Double_t distCurrent=pClus->DistTo(helix.PosPc());//ditance between current cluster and helix intersection with PC
110       if(distCurrent<distMip){distMip=distCurrent;iMipId=iClusN;}//find cluster nearest to the track 
111       
112       AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
113                                                                     helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
114     }////clusters loop for intersected chamber
115     
116     AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
117     
118     AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId);
119     Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
120     AliDebug(1,Form("FINAL Theta Cerenkov=%f",thetaCerenkov));
121 //    pTrack->SetRICHsignal(thetaCerenkov);
122
123     Double_t richPID[5]={0.2,0.2,0.2,0.2,0.2}; //start with equal probs for (e,mu,pi,k,p)
124     CalcProb(thetaCerenkov,p0.Mag(),richPID);
125     
126   }//ESD tracks loop
127   AliDebug(1,"Stop.");  
128 } //RecWithStack
129
130 Int_t AliRICHTracker::LoadClusters(TTree *pTree)
131 {
132 // Load clusters for RICH
133   AliDebug(1,"Start.");  pTree->GetEntry(0);  AliDebug(1,"Stop."); return 0;
134 }
135
136 //__________________________________________________________________________________________________
137 void AliRICHTracker::CalcProb(Double_t thetaCer,Double_t pmod, Double_t *richPID)
138 {
139 // 
140   Double_t height[5];Double_t totalHeight=0;
141   Int_t code[5]={kElectron,kMuonPlus,kPiPlus,kKPlus,kProton};
142   TDatabasePDG *db = new TDatabasePDG();
143   for(Int_t iPart=0;iPart<4;iPart++){
144     Double_t mass = db->GetParticle(code[iPart])->Mass();
145     Double_t refIndex=AliRICHParam::IndOfRefC6F14(6.755);
146     Double_t cosThetaTh = TMath::Sqrt(mass*mass+pmod*pmod)/(refIndex*pmod);
147     if(cosThetaTh>=1) {break;}
148     Double_t thetaTh = TMath::ACos(cosThetaTh);
149     Double_t sinThetaThNorm = TMath::Sin(thetaTh)/TMath::Sqrt(1-1/(refIndex*refIndex));
150     Double_t sigmaThetaTh = (0.014*(1/sinThetaThNorm-1) + 0.0043)*1.25;
151     height[iPart] = TMath::Gaus(thetaCer,thetaTh,sigmaThetaTh);
152     totalHeight +=height[iPart];
153   }
154   for(Int_t iPart=0;iPart<5;iPart++) richPID[iPart] = height[iPart]/totalHeight;    
155 }//CalcProb