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4 * Author: The ALICE Off-line Project. *
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14 **************************************************************************/
18 //-----------------------------------------------------------------
19 // Implementation of the combined PID class
20 // For the Event Summary Data Class
21 // produced by the reconstruction process
22 // and containing information on the particle identification
23 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
24 //-----------------------------------------------------------------
32 #include "AliTOFHeader.h"
33 #include "AliESDpid.h"
34 #include "AliESDEvent.h"
35 #include "AliESDtrack.h"
36 #include "AliMCEvent.h"
38 #include <AliDetectorPID.h>
42 Int_t AliESDpid::MakePID(AliESDEvent *event, Bool_t TPConly, Float_t timeZeroTOF) const {
44 // Calculate probabilities for all detectors, except if TPConly==kTRUE
47 // Option TPConly==kTRUE is used during reconstruction,
48 // because ITS tracking uses TPC pid
49 // HMPID and TRD pid are done in detector reconstructors
53 Float_t timeZeroTOF = 0;
55 timeZeroTOF = event->GetT0();
57 Int_t nTrk=event->GetNumberOfTracks();
58 for (Int_t iTrk=0; iTrk<nTrk; iTrk++) {
59 AliESDtrack *track=event->GetTrack(iTrk);
63 MakeTOFPID(track, timeZeroTOF);
64 //MakeHMPIDPID(track);
71 //_________________________________________________________________________
72 Float_t AliESDpid::GetTPCsignalTunedOnData(const AliVTrack *t) const {
73 AliESDtrack *track = (AliESDtrack *) t;
74 Float_t dedx = track->GetTPCsignalTunedOnData();
76 if(dedx > 0) return dedx;
78 dedx = t->GetTPCsignal();
79 track->SetTPCsignalTunedOnData(dedx);
80 if(dedx < 20) return dedx;
82 AliPID::EParticleType type = AliPID::kPion;
84 AliMCEventHandler* eventHandler=dynamic_cast<AliMCEventHandler*>(fEventHandler);
86 AliMCEvent* mcEvent = eventHandler->MCEvent();
89 AliMCParticle *MCpart = (AliMCParticle *) mcEvent->GetTrack(TMath::Abs(t->GetLabel()));
90 TParticle *part = MCpart->Particle();
92 Int_t iS = TMath::Abs(part->GetPdgCode());
94 if(iS==AliPID::ParticleCode(AliPID::kElectron)){
95 type = AliPID::kElectron;
97 else if(iS==AliPID::ParticleCode(AliPID::kMuon)){
100 else if(iS==AliPID::ParticleCode(AliPID::kPion)){
101 type = AliPID::kPion;
103 else if(iS==AliPID::ParticleCode(AliPID::kKaon)){
104 type = AliPID::kKaon;
106 else if(iS==AliPID::ParticleCode(AliPID::kProton)){
107 type = AliPID::kProton;
109 else if(iS==AliPID::ParticleCode(AliPID::kDeuteron)){ // d
110 type = AliPID::kDeuteron;
112 else if(iS==AliPID::ParticleCode(AliPID::kTriton)){ // t
113 type = AliPID::kTriton;
115 else if(iS==AliPID::ParticleCode(AliPID::kHe3)){ // 3He
118 else if(iS==AliPID::ParticleCode(AliPID::kAlpha)){ // 4He
119 type = AliPID::kAlpha;
125 //TODO maybe introduce different dEdxSources?
126 Double_t bethe = fTPCResponse.GetExpectedSignal(track, type, AliTPCPIDResponse::kdEdxDefault, this->UseTPCEtaCorrection());
127 Double_t sigma = fTPCResponse.GetExpectedSigma(track, type, AliTPCPIDResponse::kdEdxDefault, this->UseTPCEtaCorrection());
128 dedx = gRandom->Gaus(bethe,sigma);
129 // if(iS == AliPID::ParticleCode(AliPID::kHe3) || iS == AliPID::ParticleCode(AliPID::kAlpha)) dedx *= 5;
134 track->SetTPCsignalTunedOnData(dedx);
137 //_________________________________________________________________________
138 Float_t AliESDpid::GetTOFsignalTunedOnData(const AliVTrack *t) const {
139 AliESDtrack *track = (AliESDtrack *) t;
140 Double_t tofSignal = track->GetTOFsignalTunedOnData();
142 if(tofSignal < 99999) return (Float_t)tofSignal; // it has been already set
144 tofSignal = t->GetTOFsignal() + fTOFResponse.GetTailRandomValue();
145 track->SetTOFsignalTunedOnData(tofSignal);
146 return (Float_t)tofSignal;
148 //_________________________________________________________________________
149 void AliESDpid::MakeTPCPID(AliESDtrack *track) const
152 // TPC pid using bethe-bloch and gaussian response
154 if ((track->GetStatus()&AliESDtrack::kTPCin )==0)
155 if ((track->GetStatus()&AliESDtrack::kTPCout)==0) return;
157 Double_t mom = track->GetP();
158 const AliExternalTrackParam *in=track->GetInnerParam();
159 if (in) mom = in->GetP();
161 Double_t p[AliPID::kSPECIES];
162 Double_t dedx=track->GetTPCsignal();
163 Bool_t mismatch=kTRUE, heavy=kTRUE;
165 for (Int_t j=0; j<AliPID::kSPECIES; j++) {
166 AliPID::EParticleType type=AliPID::EParticleType(j);
167 Double_t bethe=fTPCResponse.GetExpectedSignal(mom,type);
168 Double_t sigma=fTPCResponse.GetExpectedSigma(mom,track->GetTPCsignalN(),type);
169 if (TMath::Abs(dedx-bethe) > fRange*sigma) {
170 p[j]=TMath::Exp(-0.5*fRange*fRange)/sigma;
172 p[j]=TMath::Exp(-0.5*(dedx-bethe)*(dedx-bethe)/(sigma*sigma))/sigma;
176 // Check for particles heavier than (AliPID::kSPECIES - 1)
177 if (dedx < (bethe + fRange*sigma)) heavy=kFALSE;
182 for (Int_t j=0; j<AliPID::kSPECIES; j++) p[j]=1./AliPID::kSPECIES;
186 if (heavy) track->ResetStatus(AliESDtrack::kTPCpid);
189 //_________________________________________________________________________
190 void AliESDpid::MakeITSPID(AliESDtrack *track) const
194 // Two options, depending on fITSPIDmethod:
195 // 1) Truncated mean method
196 // 2) Likelihood, using charges measured in all 4 layers and
197 // Landau+gaus response functions
200 if ((track->GetStatus()&AliESDtrack::kITSin)==0 &&
201 (track->GetStatus()&AliESDtrack::kITSout)==0) return;
203 Double_t mom=track->GetP();
204 if (fITSPIDmethod == kITSTruncMean) {
205 Double_t dedx=track->GetITSsignal();
208 ULong_t trStatus=track->GetStatus();
209 if(trStatus&AliESDtrack::kTPCin) isSA=kFALSE;
210 UChar_t clumap=track->GetITSClusterMap();
211 Int_t nPointsForPid=0;
212 for(Int_t i=2; i<6; i++){
213 if(clumap&(1<<i)) ++nPointsForPid;
216 if(nPointsForPid<3) { // track not to be used for combined PID purposes
217 track->ResetStatus(AliESDtrack::kITSpid);
223 Bool_t mismatch=kTRUE, heavy=kTRUE;
224 for (Int_t j=0; j<AliPID::kSPECIES; j++) {
225 Double_t mass=AliPID::ParticleMass(j);//GeV/c^2
226 Double_t bethe=fITSResponse.Bethe(momITS,mass);
227 Double_t sigma=fITSResponse.GetResolution(bethe,nPointsForPid,isSA);
228 if (TMath::Abs(dedx-bethe) > fRange*sigma) {
229 p[j]=TMath::Exp(-0.5*fRange*fRange)/sigma;
231 p[j]=TMath::Exp(-0.5*(dedx-bethe)*(dedx-bethe)/(sigma*sigma))/sigma;
235 // Check for particles heavier than (AliPID::kSPECIES - 1)
236 if (dedx < (bethe + fRange*sigma)) heavy=kFALSE;
241 for (Int_t j=0; j<AliPID::kSPECIES; j++) p[j]=1./AliPID::kSPECIES;
245 if (heavy) track->ResetStatus(AliESDtrack::kITSpid);
247 else { // Likelihood method
248 Double_t condprobfun[AliPID::kSPECIES];
250 track->GetITSdEdxSamples(qclu);
251 fITSResponse.GetITSProbabilities(mom,qclu,condprobfun);
252 track->SetITSpid(condprobfun);
256 //_________________________________________________________________________
257 void AliESDpid::MakeTOFPID(AliESDtrack *track, Float_t /*timeZeroTOF*/) const
260 // TOF PID using gaussian response
263 if ((track->GetStatus()&AliESDtrack::kTOFout)==0) return;
264 if ((track->GetStatus()&AliESDtrack::kTIME)==0) return;
265 if ((track->GetStatus()&AliESDtrack::kITSin)==0) return;
267 Int_t ibin = fTOFResponse.GetMomBin(track->GetP());
268 Float_t timezero = fTOFResponse.GetT0bin(ibin);
270 Double_t time[AliPID::kSPECIES];
271 track->GetIntegratedTimes(time);
273 Double_t sigma[AliPID::kSPECIES];
274 for (Int_t iPart = 0; iPart < AliPID::kSPECIES; iPart++) {
275 sigma[iPart] = fTOFResponse.GetExpectedSigma(track->GetP(),time[iPart],AliPID::ParticleMass(iPart));
278 AliDebugGeneral("AliESDpid::MakeTOFPID",2,
279 Form("Expected TOF signals [ps]: %f %f %f %f %f",
280 time[AliPID::kElectron],
284 time[AliPID::kProton]));
286 AliDebugGeneral("AliESDpid::MakeTOFPID",2,
287 Form("Expected TOF std deviations [ps]: %f %f %f %f %f",
288 sigma[AliPID::kElectron],
289 sigma[AliPID::kMuon],
290 sigma[AliPID::kPion],
291 sigma[AliPID::kKaon],
292 sigma[AliPID::kProton]
295 Double_t tof = track->GetTOFsignal() - timezero;
297 Double_t p[AliPID::kSPECIES];
298 // Bool_t mismatch = kTRUE;
299 Bool_t heavy = kTRUE;
300 for (Int_t j=0; j<AliPID::kSPECIES; j++) {
301 Double_t sig = sigma[j];
302 if (TMath::Abs(tof-time[j]) > (fRange+2)*sig) {
303 p[j] = TMath::Exp(-0.5*(fRange+2)*(fRange+2))/sig;
305 p[j] = TMath::Exp(-0.5*(tof-time[j])*(tof-time[j])/(sig*sig))/sig;
307 // Check the mismatching
309 // Double_t mass = AliPID::ParticleMass(j);
310 // Double_t pm = fTOFResponse.GetMismatchProbability(track->GetP(),mass);
311 // if (p[j]>pm) mismatch = kFALSE;
313 // Check for particles heavier than (AliPID::kSPECIES - 1)
314 if (tof < (time[j] + fRange*sig)) heavy=kFALSE;
320 for (Int_t j=0; j<AliPID::kSPECIES; j++) p[j]=1./AliPID::kSPECIES;
325 if (heavy) track->ResetStatus(AliESDtrack::kTOFpid);
327 // kTOFmismatch flas is not set because deprecated from 18/02/2013
328 // if (!CheckTOFMatching(track)) track->SetStatus(AliESDtrack::kTOFmismatch);
329 // else track->ResetStatus(AliESDtrack::kTOFmismatch);
331 //_________________________________________________________________________
332 void AliESDpid::MakeTRDPID(AliESDtrack *track) const
335 // Method to recalculate the TRD PID probabilities
337 Double_t prob[AliPID::kSPECIES];
338 GetComputeTRDProbability(track, AliPID::kSPECIES, prob);
339 track->SetTRDpid(prob);
341 //_________________________________________________________________________
342 void AliESDpid::CombinePID(AliESDtrack *track) const
345 // Combine the information of various detectors
346 // to determine the Particle Identification
348 Int_t ns=AliPID::kSPECIES;
349 Double_t p[10]={1.,1.,1.,1.,1.,1.,1.,1.,1.,1.};
351 if (track->IsOn(AliESDtrack::kITSpid)) {
354 for (Int_t j=0; j<ns; j++) p[j]*=d[j];
357 if (track->IsOn(AliESDtrack::kTPCpid)) {
360 for (Int_t j=0; j<ns; j++) p[j]*=d[j];
363 if (track->IsOn(AliESDtrack::kTRDpid)) {
366 for (Int_t j=0; j<ns; j++) p[j]*=d[j];
369 if (track->IsOn(AliESDtrack::kTOFpid)) {
372 for (Int_t j=0; j<ns; j++) p[j]*=d[j];
375 if (track->IsOn(AliESDtrack::kHMPIDpid)) {
377 track->GetHMPIDpid(d);
378 for (Int_t j=0; j<ns; j++) p[j]*=d[j];
383 //_________________________________________________________________________
384 Bool_t AliESDpid::CheckTOFMatching(AliESDtrack *track) const{
386 // Check pid matching of TOF with TPC as reference
388 Bool_t status = kFALSE;
390 Double_t exptimes[5];
391 track->GetIntegratedTimes(exptimes);
393 Float_t p = track->P();
395 Float_t dedx = track->GetTPCsignal();
396 Float_t time = track->GetTOFsignal() - fTOFResponse.GetStartTime(p);
399 track->GetInnerPxPyPz(ptpc);
400 Float_t momtpc=TMath::Sqrt(ptpc[0]*ptpc[0] + ptpc[1]*ptpc[1] + ptpc[2]*ptpc[2]);
402 for(Int_t i=0;i < 5;i++){
403 AliPID::EParticleType type=AliPID::EParticleType(i);
405 Float_t resolutionTOF = fTOFResponse.GetExpectedSigma(p, exptimes[i], AliPID::ParticleMass(i));
406 if(TMath::Abs(exptimes[i] - time) < fRange * resolutionTOF){
407 Float_t dedxExp = fTPCResponse.GetExpectedSignal(momtpc,type);
408 Float_t resolutionTPC = fTPCResponse.GetExpectedSigma(momtpc,track->GetTPCsignalN(),type);
410 if(TMath::Abs(dedx - dedxExp) < fRangeTOFMismatch * resolutionTPC){
417 Float_t resolutionTOFpr = fTOFResponse.GetExpectedSigma(p, exptimes[4], AliPID::ParticleMass(4));
418 if(!status && (exptimes[4] + fRange*resolutionTOFpr < time)) status = kTRUE;
424 //_________________________________________________________________________
425 Float_t AliESDpid::GetSignalDeltaTOFold(const AliVParticle *track, AliPID::EParticleType type, Bool_t ratio/*=kFALSE*/) const
428 // TOF signal - expected
430 AliVTrack *vtrack=(AliVTrack*)track;
432 const Double_t expTime = fTOFResponse.GetExpectedSignal(vtrack,type);
433 Double_t tofTime = 99999;
434 if (fTuneMConData && ((fTuneMConDataMask & kDetTOF) == kDetTOF) ) tofTime = (Double_t)this->GetTOFsignalTunedOnData((AliVTrack*)vtrack);
435 else tofTime=vtrack->GetTOFsignal();
436 tofTime = tofTime - fTOFResponse.GetStartTime(vtrack->P());
437 Double_t delta=-9999.;
439 if (!ratio) delta=tofTime-expTime;
440 else if (expTime>1.e-20) delta=tofTime/expTime;
445 //_________________________________________________________________________
446 Float_t AliESDpid::GetNumberOfSigmasTOFold(const AliVParticle *track, AliPID::EParticleType type) const
449 // Number of sigma implementation for the TOF
452 AliVTrack *vtrack=(AliVTrack*)track;
453 Double_t tofTime = 99999;
454 if (fTuneMConData && ((fTuneMConDataMask & kDetTOF) == kDetTOF) ) tofTime = (Double_t)this->GetTOFsignalTunedOnData((AliVTrack*)vtrack);
455 else tofTime=vtrack->GetTOFsignal();
457 Double_t expTime = fTOFResponse.GetExpectedSignal(vtrack,type);
458 return (tofTime - fTOFResponse.GetStartTime(vtrack->P()) - expTime)/fTOFResponse.GetExpectedSigma(vtrack->P(),expTime,AliPID::ParticleMassZ(type));