* provided "as is" without express or implied warranty. *
**************************************************************************/
-//-----------------------------------------------------------------
-// Implementation of the TRD PID class
-// Assigns the electron and pion liklihoods for each ESD track.
-// The function MakePID(AliESD *event) calculates the probability
-// of having dedx and the probability of having timbin at a given
-// momentum (mom) and particle type k (0 for e) and (2 for pi)
-// from the precalculated timbin distributions.
-// Prashant Shukla <shukla@pi0.physi.uni-heidelberg.de>
-//-----------------------------------------------------------------
+////////////////////////////////////////////////////////////////////////////
+// //
+// Implementation of the TRD PID class //
+// //
+// Assigns the electron and pion likelihoods to each ESD track. //
+// The function MakePID(AliESD *event) calculates the probability //
+// of having dedx and a maximum timbin at a given //
+// momentum (mom) and particle type k //
+// from the precalculated distributions. //
+// //
+// Original version: //
+// Prashant Shukla <shukla@pi0.physi.uni-heidelberg.de> //
+// //
+////////////////////////////////////////////////////////////////////////////
-#include "AliTRDpidESD.h"
+#include "AliLog.h"
#include "AliESD.h"
#include "AliESDtrack.h"
+
+#include "AliTRDpidESD.h"
+#include "AliTRDgeometry.h"
#include "AliTRDcalibDB.h"
#include "Cal/AliTRDCalPIDLQ.h"
ClassImp(AliTRDpidESD)
-//_________________________________________________________________________
-AliTRDpidESD::AliTRDpidESD(Double_t *param)
+//_____________________________________________________________________________
+AliTRDpidESD::AliTRDpidESD():TObject()
{
//
- // The main constructor
+ // Default constructor
//
- fMIP=param[0]; // MIP signal
- fRes=param[1]; // relative resolution
- fRange=param[2]; // PID "range" (in sigmas)
+
+ fCheckTrackStatus = kTRUE;
+ fCheckKinkStatus = kFALSE;
+ fMinPlane = 0;
+
}
-Double_t AliTRDpidESD::Bethe(Double_t bg)
+//_____________________________________________________________________________
+AliTRDpidESD::AliTRDpidESD(const AliTRDpidESD &p):TObject(p)
{
//
- // Parametrization of the Bethe-Bloch-curve
- // The parametrization is the same as for the TPC and is taken from Lehrhaus.
+ // AliTRDpidESD copy constructor
//
- // This parameters have been adjusted to averaged values from GEANT
- const Double_t kP1 = 7.17960e-02;
- const Double_t kP2 = 8.54196;
- const Double_t kP3 = 1.38065e-06;
- const Double_t kP4 = 5.30972;
- const Double_t kP5 = 2.83798;
-
- // This parameters have been adjusted to Xe-data found in:
- // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253
- //const Double_t kP1 = 0.76176E-1;
- //const Double_t kP2 = 10.632;
- //const Double_t kP3 = 3.17983E-6;
- //const Double_t kP4 = 1.8631;
- //const Double_t kP5 = 1.9479;
-
- // Lower cutoff of the Bethe-Bloch-curve to limit step sizes
- const Double_t kBgMin = 0.8;
- const Double_t kBBMax = 6.83298;
- //const Double_t kBgMin = 0.6;
- //const Double_t kBBMax = 17.2809;
- //const Double_t kBgMin = 0.4;
- //const Double_t kBBMax = 82.0;
-
- if (bg > kBgMin) {
- Double_t yy = bg / TMath::Sqrt(1. + bg*bg);
- Double_t aa = TMath::Power(yy,kP4);
- Double_t bb = TMath::Power((1./bg),kP5);
- bb = TMath::Log(kP3 + bb);
- return ((kP2 - aa - bb)*kP1 / aa);
- }
- else {
- return kBBMax;
- }
+ ((AliTRDpidESD &) p).Copy(*this);
+
+}
+
+//_____________________________________________________________________________
+AliTRDpidESD &AliTRDpidESD::operator=(const AliTRDpidESD &p)
+{
+ //
+ // Assignment operator
+ //
+
+ if (this != &p) ((AliTRDpidESD &) p).Copy(*this);
+ return *this;
+
+}
+
+//_____________________________________________________________________________
+void AliTRDpidESD::Copy(TObject &p) const
+{
+ //
+ // Copy function
+ //
+
+ ((AliTRDpidESD &) p).fCheckTrackStatus = fCheckTrackStatus;
+ ((AliTRDpidESD &) p).fCheckKinkStatus = fCheckKinkStatus;
+ ((AliTRDpidESD &) p).fMinPlane = fMinPlane;
}
-//_________________________________________________________________________
+//_____________________________________________________________________________
Int_t AliTRDpidESD::MakePID(AliESD *event)
{
//
- // This function calculates the "detector response" PID probabilities
+ // This function calculates the PID probabilities based on TRD signals
//
-
- AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
- if (!calibration)
+ // So far this method produces probabilities based on the total charge
+ // in each layer and the position of the maximum time bin in each layer.
+ // In a final version this should also exploit the charge measurement in
+ // the different slices of a given layer.
+ //
+
+ Double_t p[10];
+ Int_t nSpecies = AliPID::kSPECIES;
+ Int_t nPlanePID = 0;
+ Double_t mom = 0.0;
+ Double_t probTotal = 0.0;
+
+ AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
+ if (!calibration) {
+ //AliError("No access to calibration data\n");
return -1;
-
- // The class AliTRDCalPIDLQ contains precalculated prob dis.
+ }
+
+ // Retrieve the CDB container class with the probability distributions
const AliTRDCalPIDLQ *pd = calibration->GetPIDLQObject();
- if (!pd) return -1;
-
- // Example to get mean for particle 2 (pi) and momentum number 4 (2 GeV)
- // printf("%.2f \n", pd->GetMean(2, 4));
- // Example of use of Copy Constructor
- // AliTRDCalPIDLQ *pd1 = new AliTRDCalPIDLQ(*pd);
-
- Int_t ntrk=event->GetNumberOfTracks();
- for (Int_t i=0; i<ntrk; i++) {
- AliESDtrack *t=event->GetTrack(i);
- if ((t->GetStatus()&AliESDtrack::kTRDin)==0)
- if ((t->GetStatus()&AliESDtrack::kTRDout)==0)
- if ((t->GetStatus()&AliESDtrack::kTRDrefit)==0) continue;
- if(t->GetTRDsignal()==0) continue;
- // Int_t ns=AliESDtrack::kSPECIES;
- Int_t ns=AliPID::kSPECIES;
- Double_t p[10];
- Double_t mom=t->GetP();
- Double_t probTotal=0.0;
- for (Int_t j=0; j<ns; j++) {
- p[j]=1.;
- for (Int_t ilayer=0; ilayer <6; ilayer++) {
- Double_t dedx=t->GetTRDsignals(ilayer,1);
- Int_t timbin=t->GetTRDTimBin(ilayer);
- p[j]*= pd->GetProbability(j,mom,dedx);
- p[j]*= pd->GetProbabilityT(j,mom,timbin);
- p[j]*= 100;
- } // loop over layers
- probTotal+=p[j];
- } //loop over particle species
- // printf(" %f %d %f %f %f \n", mom, timbin, p[0], p[1], p[2]);
- for (Int_t j=0; j<ns; j++) {
- if(probTotal) p[j]/= probTotal;
- else p[j]=1.0;
- // p[j]=1.;
- } //loop over particle species
+ if (!pd) {
+ //AliError("No access to AliTRDCalPIDLQ\n");
+ return -1;
+ }
+
+ // Loop through all ESD tracks
+ Int_t ntrk = event->GetNumberOfTracks();
+ for (Int_t i = 0; i < ntrk; i++) {
+
+ AliESDtrack *t = event->GetTrack(i);
+
+ // Check the ESD track status
+ if (fCheckTrackStatus) {
+ if (((t->GetStatus() & AliESDtrack::kTRDout ) == 0) &&
+ ((t->GetStatus() & AliESDtrack::kTRDrefit) == 0)) {
+ continue;
+ }
+ }
+
+ // Check for ESD kink tracks
+ if (fCheckKinkStatus) {
+ if (t->GetKinkIndex(0) != 0) {
+ continue;
+ }
+ }
+
+ // Skip tracks that have no TRD signal at all
+ if (t->GetTRDsignal() == 0) {
+ continue;
+ }
+
+ mom = t->GetP();
+ probTotal = 0.0;
+ nPlanePID = 0;
+ for (Int_t iSpecies = 0; iSpecies < nSpecies; iSpecies++) {
+ p[iSpecies] = 1.0;
+ }
+
+ // Check the different detector layers
+ for (Int_t iPlan = 0; iPlan < AliTRDgeometry::kNplan; iPlan++) {
+
+ // Use the total charge in a given plane
+ Double_t dedx = t->GetTRDsignals(iPlan,-1);
+ Int_t timebin = t->GetTRDTimBin(iPlan);
+ if ((dedx > 0.0) &&
+ (timebin > -1.0)) {
+
+ nPlanePID++;
+
+ // Get the probabilities for the different particle species
+ for (Int_t iSpecies = 0; iSpecies < nSpecies; iSpecies++) {
+
+ p[iSpecies] *= pd->GetProbability(iSpecies,mom,dedx);
+ p[iSpecies] *= pd->GetProbabilityT(iSpecies,mom,timebin);
+ p[iSpecies] *= 100.0; // ??????????????
+
+ probTotal += p[iSpecies];
+
+ }
+
+ }
+
+ }
+
+ for (Int_t iSpecies = 0; iSpecies < nSpecies; iSpecies++) {
+ if ((probTotal > 0.0) &&
+ (nPlanePID > fMinPlane)) {
+ p[iSpecies] /= probTotal;
+ }
+ else {
+ p[iSpecies] = 1.0;
+ }
+ }
+
t->SetTRDpid(p);
- } //loop over tracks
+
+ }
+
return 0;
+
}
/* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
* See cxx source for full Copyright notice */
-//-------------------------------------------------------
-// TRD PID class
-// A very naive design...
-//-------------------------------------------------------
+/* $Id$ */
+
+////////////////////////////////////////////////////////////////////////////
+// //
+// Assigns the PID probabilities based on TRD information to the ESDs //
+// //
+////////////////////////////////////////////////////////////////////////////
+
#include <Rtypes.h>
+#include <TObject.h>
+
class AliESD;
-class AliTRDpidESD {
-public:
- AliTRDpidESD(Double_t *param);
+class AliTRDpidESD : public TObject {
+
+ public:
+
+ AliTRDpidESD();
+ AliTRDpidESD(const AliTRDpidESD &p);
virtual ~AliTRDpidESD() {}
- static Int_t MakePID(AliESD *event);
- static Double_t Bethe(Double_t bg);
-private:
- Double_t fMIP; // dEdx for MIP
- Double_t fRes; // relative dEdx resolution
- Double_t fRange; // one particle type PID range (in sigmas)
- ClassDef(AliTRDpidESD,1) // TRD PID class
+ AliTRDpidESD &operator=(const AliTRDpidESD &p);
+
+ virtual void Copy(TObject &p) const;
+
+ static Int_t MakePID(AliESD *event);
+
+ void SetCheckTrackStatus(Bool_t status = kTRUE) { fCheckTrackStatus = status; };
+ void SetCheckKinkStatus(Bool_t status = kTRUE) { fCheckKinkStatus = status; };
+ void SetMinPlane(Int_t plane) { fMinPlane = plane; };
+
+ Bool_t GetCheckTrackStatus() { return fCheckTrackStatus; };
+ Bool_t GetCheckKinkStatus() { return fCheckKinkStatus; };
+ Int_t GetMinPlane() { return fMinPlane; };
+
+ private:
+
+ static Bool_t fCheckTrackStatus; // Enable check on ESD track status
+ static Bool_t fCheckKinkStatus; // Enable check on ESD kink track
+ static Int_t fMinPlane; // Minimum number of planes
+
+ ClassDef(AliTRDpidESD,2) // TRD PID class
+
};
#endif
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