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16 /* $Id: AliAODpidUtil.cxx 38329 2010-01-17 19:17:24Z hristov $ */
18 //-----------------------------------------------------------------
19 // Implementation of the combined PID class
21 // containing information on the particle identification
22 // Origin: Rosa Romita, GSI, r.romita@gsi.de
23 //-----------------------------------------------------------------
28 #include "AliAODpidUtil.h"
29 #include "AliAODEvent.h"
30 #include "AliAODTrack.h"
31 #include "AliAODPid.h"
32 #include "AliTRDPIDResponse.h"
33 #include "AliESDtrack.h"
34 #include "AliAODMCHeader.h"
35 #include "AliAODMCParticle.h"
37 ClassImp(AliAODpidUtil)
39 Int_t AliAODpidUtil::MakePID(const AliAODTrack *track,Double_t *p) const {
41 // Calculate probabilities for all detectors, except if TPConly==kTRUE
44 // Option TPConly==kTRUE is used during reconstruction,
45 // because ITS tracking uses TPC pid
46 // HMPID and TRD pid are done in detector reconstructors
50 Float_t TimeZeroTOF = 0;
52 TimeZeroTOF = event->GetT0();
54 Int_t ns=AliPID::kSPECIES;
55 Double_t tpcPid[AliPID::kSPECIES];
56 MakeTPCPID(track,tpcPid);
57 Double_t itsPid[AliPID::kSPECIES];
58 Double_t tofPid[AliPID::kSPECIES];
59 Double_t trdPid[AliPID::kSPECIES];
60 MakeITSPID(track,itsPid);
61 MakeTOFPID(track,tofPid);
62 //MakeHMPIDPID(track);
63 MakeTRDPID(track,trdPid);
64 for (Int_t j=0; j<ns; j++) {
65 p[j]=tpcPid[j]*itsPid[j]*tofPid[j]*trdPid[j];
70 //_________________________________________________________________________
71 Float_t AliAODpidUtil::GetTPCsignalTunedOnData(const AliVTrack *t) const {
72 AliAODTrack *track = (AliAODTrack *) t;
73 Float_t dedx = track->GetTPCsignalTunedOnData();
74 if(dedx > 0) return dedx;
76 Double_t mom = t->GetTPCmomentum();
78 dedx = t->GetTPCsignal();
79 track->SetTPCsignalTunedOnData(dedx);
81 if(dedx < 20) return dedx;
84 AliPID::EParticleType type = AliPID::kPion;
86 AliAODMCHeader *mcHeader = dynamic_cast<AliAODMCHeader*>(track->GetAODEvent()->GetList()->FindObject(AliAODMCHeader::StdBranchName()));
88 TClonesArray *mcArray = (TClonesArray*)track->GetAODEvent()->GetList()->FindObject(AliAODMCParticle::StdBranchName());
92 Int_t iS = TMath::Abs(((AliAODMCParticle*)mcArray->At(TMath::Abs(t->GetLabel())))->GetPdgCode());
93 if(iS==AliPID::ParticleCode(AliPID::kElectron)){
94 type = AliPID::kElectron;
96 else if(iS==AliPID::ParticleCode(AliPID::kMuon)){
99 else if(iS==AliPID::ParticleCode(AliPID::kPion)){
100 type = AliPID::kPion;
102 else if(iS==AliPID::ParticleCode(AliPID::kKaon)){
103 type = AliPID::kKaon;
105 else if(iS==AliPID::ParticleCode(AliPID::kProton)){
106 type = AliPID::kProton;
108 else if(iS==AliPID::ParticleCode(AliPID::kDeuteron)){ // d
109 type = AliPID::kDeuteron;
111 else if(iS==AliPID::ParticleCode(AliPID::kTriton)){ // t
112 type = AliPID::kTriton;
114 else if(iS==AliPID::ParticleCode(AliPID::kHe3)){ // 3He
117 else if(iS==AliPID::ParticleCode(AliPID::kAlpha)){ // 4He
118 type = AliPID::kAlpha;
124 Double_t bethe=fTPCResponse.GetExpectedSignal(mom,type);
125 Double_t sigma=fTPCResponse.GetExpectedSigma(mom,t->GetTPCsignalN(),type);
126 dedx = gRandom->Gaus(bethe,sigma);
128 if(iS == AliPID::ParticleCode(AliPID::kHe3) || iS == AliPID::ParticleCode(AliPID::kAlpha)) dedx *= 5;
133 track->SetTPCsignalTunedOnData(dedx);
136 //_________________________________________________________________________
137 void AliAODpidUtil::MakeTPCPID(const AliAODTrack *track,Double_t *p) const
140 // TPC pid using bethe-bloch and gaussian response
143 if ((track->GetStatus()&AliESDtrack::kTPCin )==0) return;
145 AliAODPid *pidObj = track->GetDetPid();
146 Double_t mom = track->P();
148 UShort_t nTPCClus = 0;
150 nTPCClus = pidObj->GetTPCsignalN();
151 dedx = pidObj->GetTPCsignal();
152 mom = pidObj->GetTPCmomentum();
155 Bool_t mismatch=kTRUE;
157 for (Int_t j=0; j<AliPID::kSPECIES; j++) {
158 AliPID::EParticleType type=AliPID::EParticleType(j);
159 Double_t bethe=fTPCResponse.GetExpectedSignal(mom,type);
160 Double_t sigma=fTPCResponse.GetExpectedSigma(mom,nTPCClus,type);
161 if (TMath::Abs(dedx-bethe) > fRange*sigma) {
162 p[j]=TMath::Exp(-0.5*fRange*fRange)/sigma;
164 p[j]=TMath::Exp(-0.5*(dedx-bethe)*(dedx-bethe)/(sigma*sigma))/sigma;
171 for (Int_t j=0; j<AliPID::kSPECIES; j++) p[j]=1./AliPID::kSPECIES;
176 //_________________________________________________________________________
177 void AliAODpidUtil::MakeITSPID(const AliAODTrack *track,Double_t *p) const
181 // 1) Truncated mean method
185 if ((track->GetStatus()&AliESDtrack::kITSin)==0) return;
186 UChar_t clumap=track->GetITSClusterMap();
187 Int_t nPointsForPid=0;
188 for(Int_t i=2; i<6; i++){
189 if(clumap&(1<<i)) ++nPointsForPid;
191 if(nPointsForPid<3) { // track not to be used for combined PID purposes
192 for (Int_t j=0; j<AliPID::kSPECIES; j++)
193 p[j] = 1./AliPID::kSPECIES;
196 Double_t mom=track->P();
197 AliAODPid *pidObj = track->GetDetPid();
201 dedx = pidObj->GetITSsignal();
204 Bool_t mismatch = kTRUE;
206 if(track->GetStatus() & AliESDtrack::kTPCin){
209 mom = pidObj->GetTPCmomentum();
211 for (Int_t j=0; j<AliPID::kSPECIES; j++) {
212 Double_t mass = AliPID::ParticleMass(j);//GeV/c^2
213 Double_t bethe = fITSResponse.Bethe(mom,mass);
214 Double_t sigma = fITSResponse.GetResolution(bethe,nPointsForPid,isSA);
215 if (TMath::Abs(dedx-bethe) > fRange*sigma) {
216 p[j]=TMath::Exp(-0.5*fRange*fRange)/sigma;
218 p[j]=TMath::Exp(-0.5*(dedx-bethe)*(dedx-bethe)/(sigma*sigma))/sigma;
222 // Check for particles heavier than (AliPID::kSPECIES - 1)
227 for (Int_t j=0; j<AliPID::kSPECIES; j++) p[j]=1./AliPID::kSPECIES;
232 //_________________________________________________________________________
233 void AliAODpidUtil::MakeTOFPID(const AliAODTrack *track, Double_t *p) const
236 // TOF PID using gaussian response
238 if ((track->GetStatus()&AliESDtrack::kTOFout )==0) return;
239 if ((track->GetStatus()&AliESDtrack::kTIME )==0) return;
240 if ((track->GetStatus()&AliESDtrack::kTOFpid )==0) return;
242 Double_t time[AliPID::kSPECIESN];
243 Double_t sigma[AliPID::kSPECIESN];
244 AliAODPid *pidObj = track->GetDetPid();
245 pidObj->GetIntegratedTimes(time);
247 for (Int_t iPart = 0; iPart < AliPID::kSPECIES; iPart++) {
248 sigma[iPart] = fTOFResponse.GetExpectedSigma(track->P(),time[iPart],AliPID::ParticleMass(iPart));
251 AliDebugGeneral("AliESDpid::MakeTOFPID",2,
252 Form("Expected TOF signals [ps]: %f %f %f %f %f",
253 time[AliPID::kElectron],
257 time[AliPID::kProton]));
259 AliDebugGeneral("AliESDpid::MakeTOFPID",2,
260 Form("Expected TOF std deviations [ps]: %f %f %f %f %f",
261 sigma[AliPID::kElectron],
262 sigma[AliPID::kMuon],
263 sigma[AliPID::kPion],
264 sigma[AliPID::kKaon],
265 sigma[AliPID::kProton]
268 Double_t tof = pidObj->GetTOFsignal();
270 Bool_t mismatch = kTRUE;
271 for (Int_t j=0; j<AliPID::kSPECIES; j++) {
272 Double_t sig = sigma[j];
273 if (TMath::Abs(tof-time[j]) > fRange*sig) {
274 p[j] = TMath::Exp(-0.5*fRange*fRange)/sig;
276 p[j] = TMath::Exp(-0.5*(tof-time[j])*(tof-time[j])/(sig*sig))/sig;
278 // Check the mismatching
279 Double_t mass = AliPID::ParticleMass(j);
280 Double_t pm = fTOFResponse.GetMismatchProbability(track->P(),mass);
281 if (p[j]>pm) mismatch = kFALSE;
283 // Check for particles heavier than (AliPID::kSPECIES - 1)
288 for (Int_t j=0; j<AliPID::kSPECIES; j++) p[j]=1./AliPID::kSPECIES;
292 //_________________________________________________________________________
293 void AliAODpidUtil::MakeTRDPID(const AliAODTrack *track,Double_t *p) const
295 ComputeTRDProbability(track, AliPID::kSPECIES, p);