1 #include "AliRICHTracker.h"
6 #include "AliRICHHelix.h"
8 #include "AliRICHRecon.h"
10 #include <TParticle.h>
13 ClassImp(AliRICHTracker)
14 //__________________________________________________________________________________________________
15 Int_t AliRICHTracker::PropagateBack(AliESD *pESD)
17 // Interface callback methode invoked by AliRecontruction during tracking after TOF
18 // It steers to different way to provide the final reconstructed information sutable for analisys:
19 // 1. AliESD - reconstructed tracks are used
20 // 2. RICH private ntuple for debug- stack particles used instead of reconstructed tracks
21 AliDebug(1,"Start pattern recognition");
22 if(pESD->GetNumberOfTracks())
26 AliDebug(1,"Stop pattern recognition");
27 return 0; // error code: 0=no error;
29 //__________________________________________________________________________________________________
30 void AliRICHTracker::RecWithESD(AliESD *pESD)
32 //recontruction from ESD- primary way to reconstruct particle ID signal from tracks provided by core detectors
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));
38 AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
40 for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//ESD tracks loop
41 AliESDtrack *pTrack = pESD->GetTrack(iTrackN);// get next reconstructed track
42 // if((pTrack->GetStatus()&AliESDtrack::kTOFout)==0) continue; //ignore tracks not recontructed by TOF
43 // pTrack->GetXYZ(xb);
44 // pTrack->GetPxPyPz(pb);
45 Int_t status=pTrack->GetStatus()&AliESDtrack::kTOFout;//get running track parameters
46 Int_t charge = (Int_t)(-TMath::Sign(1.,pTrack->GetSign()*b));
47 AliDebug(1,Form("Track %i pmod=%f charge=%i stat=%i",iTrackN,pTrack->GetP(),charge,status));
48 AliRICHHelix helix(pTrack->X3(),pTrack->P3(),charge,b);
49 Int_t iChamber=helix.RichIntersect(pRich->P());
50 AliDebug(1,Form("intersection with %i chamber found",iChamber));
51 if(!iChamber) continue;//intersection with no chamber found
52 //find MIP cluster candidate (cluster which is closest to track intersection point)
53 Double_t distMip=9999,distX=0,distY=0; //min distance between clusters and track position on PC
54 Int_t iMipId=0; //index of that min distance cluster
55 Double_t chargeMip=0; //charge of the MIP
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());//distance between current cluster and helix intersection with PC
59 if(distCurrent<distMip){
62 distX=pClus->DistX(helix.PosPc());
63 distY=pClus->DistY(helix.PosPc());
65 }//find cluster nearest to the track
66 AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
67 helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
68 }//clusters loop for intersected chamber
70 AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
72 // HERE CUTS ON GOLD RINGS....
74 if(distMip>1||chargeMip<100) {
75 //track not accepted for pattern recognition
76 pTrack->SetRICHsignal(-999.); //to be improved by flags...
80 AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId); //actual job is done there
82 Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
84 pTrack->SetRICHcluster(iMipId+100000*iChamber);
85 pTrack->SetRICHdxdy(distX,distY);
86 pTrack->SetRICHthetaPhi(helix.Ploc().Theta(),helix.Ploc().Phi());
87 pTrack->SetRICHsignal(thetaCerenkov);
88 pTrack->SetRICHnclusters(recon.GetHoughPhotons());
90 AliDebug(1,Form("FINAL Theta Cerenkov=%f",pTrack->GetRICHsignal()));
92 if(pTrack->GetRICHsignal()>0) {
93 AliDebug(1,Form("Start to assign the probabilities"));
94 Double_t sigmaPID[AliPID::kSPECIES];
95 Double_t richPID[AliPID::kSPECIES];
96 for (Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++) {
98 for(Int_t iphot=0;iphot<pRich->Clusters(iChamber)->GetEntries();iphot++) {
99 recon.SetPhotonIndex(iphot);
100 if(recon.GetPhotonFlag() == 2) {
101 Double_t sigma = AliRICHParam::SigmaSinglePhoton(iPart,pTrack->GetP(),recon.GetTrackTheta(),recon.GetPhiPoint()-recon.GetTrackPhi()).Mag();
102 sigmaPID[iPart] += 1/(sigma*sigma);
105 sigmaPID[iPart] = 1/TMath::Sqrt(sigmaPID[iPart])*0.001;
106 AliDebug(1,Form("sigma for %s is %f rad",AliPID::ParticleName(iPart),sigmaPID[iPart]));
108 CalcProb(thetaCerenkov,pTrack->GetP(),sigmaPID,richPID);
109 pTrack->SetRICHpid(richPID);
110 AliDebug(1,Form("PROBABILITIES ---> %f - %f - %f - %f - %f",richPID[0],richPID[1],richPID[2],richPID[3],richPID[4]));
117 //__________________________________________________________________________________________________
118 void AliRICHTracker::RecWithStack(TNtupleD *hn)
120 //Reconstruction for particles from STACK. This methode is to be used for RICH standalone when no other detectors are switched on,
121 //so normal tracking is not available
122 AliDebug(1,"Start.");
123 AliRICH *pRich=((AliRICH*)gAlice->GetDetector("RICH"));
125 // pRich->GetLoader()->GetRunLoader()->LoadHeader();
126 if(!pRich->GetLoader()->GetRunLoader()->TreeK()) pRich->GetLoader()->GetRunLoader()->LoadKinematics();
127 AliStack *pStack = pRich->GetLoader()->GetRunLoader()->Stack();
128 if(!pStack) {AliDebug(1,Form("No STACK found in AliRoot"));return;}
129 Int_t iNtracks=pStack->GetNtrack();
130 AliDebug(1,Form(" Start reconstruction with %i track(s) from Stack",iNtracks));
134 Double_t b=GetFieldMap()->SolenoidField()/10;// magnetic field in Tesla
135 AliDebug(1,Form("Start with simulated %i tracks in %f Tesla field",iNtracks,b));
136 TVector3 x0(0,0,0); TVector3 p0(0,0,0);//tmp storage for AliRICHHelix
139 if(pRich->GetLoader()->LoadRecPoints()) {AliDebug(1,Form("No clusters found in RICH"));return;}
140 pRich->GetLoader()->TreeR()->GetEntry(0);
142 for(Int_t iTrackN=0;iTrackN<iNtracks;iTrackN++){//stack particles loop
143 TParticle *pParticle = pStack->Particle(iTrackN);
144 if(!pParticle) {AliDebug(1,Form("Not a valid TParticle pointer. Track skipped"));continue;}
145 AliDebug(1,Form(" PDG code : %i",pParticle->GetPdgCode()));
147 // problem of PDG code of some extra particles to be solved!!!!!!!!!
149 // found problem! Look in TRD directory : codes from Fluka are :
151 // if ((pdg_code == 10010020) ||
152 // (pdg_code == 10010030) ||
153 // (pdg_code == 50000050) ||
154 // (pdg_code == 50000051) ||
155 // (pdg_code == 10020040)) {
157 if(pParticle->GetPdgCode()>=50000050||pParticle->GetPdgCode()==0||pParticle->GetPdgCode()>10000) {AliDebug(1,Form("A photon as track... Track skipped"));continue;}
159 // to be updated for us!!
161 AliDebug(1,Form("Track %i is a %s with charge %i and momentum %f",
162 iTrackN,pParticle->GetPDG()->GetName(),Int_t(pParticle->GetPDG()->Charge()),pParticle->P()));
163 // if(pParticle->GetMother(0)!=-1) continue; //consider only primaries
164 if(pParticle->GetPDG()->Charge()==0||TMath::Abs(Int_t(pParticle->GetPDG()->Charge()))!=3) continue; //to avoid photons from stack...
165 hnvec[0]=pParticle->P();
166 hnvec[1]=pParticle->GetPDG()->Charge();
167 p0.SetMagThetaPhi(pParticle->P(),pParticle->Theta(),pParticle->Phi());
168 x0.SetXYZ(pParticle->Vx(),pParticle->Vy(),pParticle->Vz());
169 AliRICHHelix helix(x0,p0,TMath::Sign(1,(Int_t)pParticle->GetPDG()->Charge()),b);
170 Int_t iChamber=helix.RichIntersect(pRich->P());
171 hnvec[2]=helix.Ploc().Theta();
172 hnvec[3]=helix.Ploc().Phi();
173 AliDebug(1,Form("intersection with %i chamber found",iChamber));
174 if(!iChamber) continue;// no intersection with RICH found
175 hnvec[4]=helix.PosPc().X();
176 hnvec[5]=helix.PosPc().Y();
177 Double_t distMip=9999; //min distance between clusters and track position on PC
178 Double_t mipX=-1; //min distance between clusters and track position on PC
179 Double_t mipY=-1; //min distance between clusters and track position on PC
180 Double_t chargeMip=-1; // charge MIP to find
181 Int_t iMipId=-1; //index of that min distance cluster
182 for(Int_t iClusN=0;iClusN<pRich->Clusters(iChamber)->GetEntries();iClusN++){//clusters loop for intersected chamber
183 AliRICHCluster *pClus=(AliRICHCluster*)pRich->Clusters(iChamber)->UncheckedAt(iClusN);//get pointer to current cluster
184 Double_t distCurrent=pClus->DistTo(helix.PosPc());//ditance between current cluster and helix intersection with PC
185 if(distCurrent<distMip){distMip=distCurrent;mipX=pClus->X();
187 chargeMip=pClus->Q();iMipId=1000000*iChamber+iClusN;}//find cluster nearest to the track
189 AliDebug(1,Form("Ploc (%f,%f,%f) dist= %f",helix.Ploc().Mag(),helix.Ploc().Theta()*TMath::RadToDeg(),
190 helix.Ploc().Phi()*TMath::RadToDeg(),pClus->DistTo(helix.PosPc())));
191 }//clusters loop for intersected chamber
193 AliDebug(1,Form("Min distance cluster: %i dist is %f",iMipId,distMip));
194 hnvec[6]=mipX;hnvec[7]=mipY;
196 AliRICHRecon recon(&helix,pRich->Clusters(iChamber),iMipId);
197 Double_t thetaCerenkov=recon.ThetaCerenkov(); //search for mean Cerenkov angle for this track
198 hnvec[9]=thetaCerenkov;
199 hnvec[10]=recon.GetHoughPhotons();
200 hnvec[11]=(Double_t)iMipId;
201 hnvec[12]=(Double_t)iChamber;
202 hnvec[13]=(Double_t)pParticle->GetPdgCode();
203 if(hn) hn->Fill(hnvec);
204 AliDebug(1,Form("FINAL Theta Cerenkov=%f",thetaCerenkov));
205 }//stack particles loop
207 pRich->GetLoader()->UnloadRecPoints();
210 //__________________________________________________________________________________________________
211 Int_t AliRICHTracker::LoadClusters(TTree *pTree)
213 // Load clusters for RICH
214 AliDebug(1,"Start."); pTree->GetEntry(0); AliDebug(1,"Stop."); return 0;
216 //__________________________________________________________________________________________________
217 void AliRICHTracker::CalcProb(Double_t thetaCer,Double_t pmod, Double_t *sigmaPID, Double_t *richPID)
219 // Calculates probability to be a electron-muon-pion-kaon-proton
220 // from the given Cerenkov angle and momentum assuming no initial particle composition
221 // (i.e. apriory probability to be the particle of the given sort is the same for all sorts)
222 Double_t height[AliPID::kSPECIES];Double_t totalHeight=0;
223 Double_t thetaTh[AliPID::kSPECIES];
224 for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++){
226 Double_t mass = AliPID::ParticleMass(iPart);
227 Double_t refIndex=AliRICHParam::RefIdxC6F14(AliRICHParam::MeanCkovEnergy());
228 Double_t cosThetaTh = TMath::Sqrt(mass*mass+pmod*pmod)/(refIndex*pmod);
230 if(cosThetaTh>=1) continue;
231 thetaTh[iPart] = TMath::ACos(cosThetaTh);
232 // Double_t sinThetaThNorm = TMath::Sin(thetaTh)/TMath::Sqrt(1-1/(refIndex*refIndex));
233 // Double_t sigmaThetaTh = (0.014*(1/sinThetaThNorm-1) + 0.0043)*1.25;
234 // height[iPart] = TMath::Gaus(thetaCer,thetaTh,sigmaThetaTh);
235 height[iPart] = TMath::Gaus(thetaCer,thetaTh[iPart],sigmaPID[iPart],kTRUE);
236 totalHeight +=height[iPart];
237 AliDebug(1,Form(" Particle %s with mass %f with height %f and thetaTH %f",AliPID::ParticleName(iPart),mass,height[iPart],thetaTh[iPart]));
238 AliDebug(1,Form(" partial height %15.14f total height %15.14f",height[iPart],totalHeight));
240 if(totalHeight<1e-5) {for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++)richPID[iPart]=1.0/AliPID::kSPECIES;return;}
241 for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++) richPID[iPart] = height[iPart]/totalHeight;
242 Int_t iPartNear = TMath::LocMax(AliPID::kSPECIES,richPID);
243 if(TMath::Abs(thetaCer-thetaTh[iPartNear])/sigmaPID[iPartNear]>3) for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++)richPID[iPart]=1.0/AliPID::kSPECIES;
244 //last line is to check if the nearest thetacerenkov to the teorethical one is within 3 sigma, otherwise no response (equal prob to every particle
247 //__________________________________________________________________________________________________