/**************************************************************************
- * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
- * *
- * Author: The ALICE Off-line Project. *
- * Contributors are mentioned in the code where appropriate. *
- * *
- * Permission to use, copy, modify and distribute this software and its *
- * documentation strictly for non-commercial purposes is hereby granted *
- * without fee, provided that the above copyright notice appears in all *
- * copies and that both the copyright notice and this permission notice *
- * appear in the supporting documentation. The authors make no claims *
- * about the suitability of this software for any purpose. It is *
- * provided "as is" without express or implied warranty. *
- **************************************************************************/
+* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
+* *
+* Author: The ALICE Off-line Project. *
+* Contributors are mentioned in the code where appropriate. *
+* *
+* Permission to use, copy, modify and distribute this software and its *
+* documentation strictly for non-commercial purposes is hereby granted *
+* without fee, provided that the above copyright notice appears in all *
+* copies and that both the copyright notice and this permission notice *
+* appear in the supporting documentation. The authors make no claims *
+* about the suitability of this software for any purpose. It is *
+* provided "as is" without express or implied warranty. *
+**************************************************************************/
/* $Id$ */
// Implementation of the TRD PID class //
// //
// Assigns the electron and pion likelihoods to each ESD track. //
-// The function MakePID(AliESD *event) calculates the probability //
+// The function MakePID(AliESDEvent *event) calculates the probability //
// of having dedx and a maximum timbin at a given //
// momentum (mom) and particle type k //
// from the precalculated distributions. //
// //
// Authors : //
-// Prashant Shukla <shukla@pi0.physi.uni-heidelberg.de> (Original version)//
-// Alex Bercuci (a.bercuci@gsi.de) //
+// Prashant Shukla <shukla@pi0.physi.uni-heidelberg.de> (orig. version) //
+// Alex Bercuci (a.bercuci@gsi.de) //
// //
////////////////////////////////////////////////////////////////////////////
-#include "AliLog.h"
-#include "AliESD.h"
+#include "AliESDEvent.h"
#include "AliESDtrack.h"
+#include "AliTracker.h"
#include "AliTRDpidESD.h"
#include "AliTRDgeometry.h"
#include "AliTRDcalibDB.h"
-#include "AliRun.h"
-#include "AliTRDtrack.h"
-#include "Cal/AliTRDCalPIDLQ.h"
+#include "Cal/AliTRDCalPID.h"
ClassImp(AliTRDpidESD)
- Bool_t AliTRDpidESD::fCheckTrackStatus = kTRUE;
- Bool_t AliTRDpidESD::fCheckKinkStatus = kFALSE;
- Int_t AliTRDpidESD::fMinPlane = 0;
+Bool_t AliTRDpidESD::fgCheckTrackStatus = kTRUE;
+Bool_t AliTRDpidESD::fgCheckKinkStatus = kFALSE;
+Int_t AliTRDpidESD::fgMinPlane = 0;
//_____________________________________________________________________________
AliTRDpidESD::AliTRDpidESD()
:TObject()
+ ,fTrack(NULL)
{
//
// Default constructor
//_____________________________________________________________________________
AliTRDpidESD::AliTRDpidESD(const AliTRDpidESD &p)
:TObject(p)
+ ,fTrack(NULL)
{
//
// AliTRDpidESD copy constructor
}
+//_____________________________________________________________________________
+AliTRDpidESD::~AliTRDpidESD()
+{
+ //
+ // Destructor
+ //
+
+ if(fTrack) delete fTrack;
+
+}
+
//_____________________________________________________________________________
AliTRDpidESD &AliTRDpidESD::operator=(const AliTRDpidESD &p)
{
// Copy function
//
- ((AliTRDpidESD &) p).fCheckTrackStatus = fCheckTrackStatus;
- ((AliTRDpidESD &) p).fCheckKinkStatus = fCheckKinkStatus;
- ((AliTRDpidESD &) p).fMinPlane = fMinPlane;
-
+ ((AliTRDpidESD &) p).fgCheckTrackStatus = fgCheckTrackStatus;
+ ((AliTRDpidESD &) p).fgCheckKinkStatus = fgCheckKinkStatus;
+ ((AliTRDpidESD &) p).fgMinPlane = fgMinPlane;
+ ((AliTRDpidESD &) p).fTrack = NULL;
+
}
//_____________________________________________________________________________
-Int_t AliTRDpidESD::MakePID(AliESD *event)
+Int_t AliTRDpidESD::MakePID(AliESDEvent * const event)
{
//
// This function calculates the PID probabilities based on TRD signals
// The method produces probabilities based on the charge
// and the position of the maximum time bin in each layer.
// The dE/dx information can be used as global charge or 2 to 3
- // slices. Check AliTRDCalPIDLQ and AliTRDCalPIDLQRef for the actual
+ // slices. Check AliTRDCalPID and AliTRDCalPIDRefMaker for the actual
// implementation.
//
// Author
// Alex Bercuci (A.Bercuci@gsi.de) 2nd May 2007
+ //
+
+ AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
+ if (!calibration) {
+ AliErrorGeneral("AliTRDpidESD::MakePID()"
+ ,"No access to calibration data");
+ return -1;
+ }
+
+// AliTRDrecoParam *rec = AliTRDReconstructor::RecoParam();
+// if (!rec) {
+// AliErrorGeneral("AliTRDpidESD::MakePID()", "No TRD reco param.");
+// return 0x0;
+// }
+
+ // Retrieve the CDB container class with the probability distributions
+ const AliTRDCalPID *pd = calibration->GetPIDObject(AliTRDpidUtil::kLQ);
+ if (!pd) {
+ AliErrorGeneral("AliTRDpidESD::MakePID()"
+ ,"No access to AliTRDCalPID");
+ return -1;
+ }
+
+ // Loop through all ESD tracks
+ Double_t p[10];
+ AliESDtrack *t = NULL;
+ Float_t dedx[AliTRDCalPID::kNSlicesLQ], dEdx;
+ Int_t timebin;
+ Float_t mom, length;
+ Int_t nPlanePID;
+ for (Int_t i=0; i<event->GetNumberOfTracks(); i++) {
+ t = event->GetTrack(i);
+
+ // Check track
+ if(!CheckTrack(t)) continue;
+
+
+ // Skip tracks which have no TRD signal at all
+ if (t->GetTRDsignal()<1.e-5) continue;
+
+ // Loop over detector layers
+ mom = 0.;
+ length = 0.;
+ nPlanePID = 0;
+ for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++)
+ p[iSpecies] = 1./AliPID::kSPECIES;
+
+ for (Int_t iLayer = 0; iLayer < AliTRDgeometry::kNlayer; iLayer++) {
+ // read data for track segment
+ for(int iSlice=0; iSlice<AliTRDCalPID::kNSlicesLQ; iSlice++)
+ dedx[iSlice] = t->GetTRDslice(iLayer, iSlice);
+ dEdx = t->GetTRDslice(iLayer, -1);
+ timebin = t->GetTRDTimBin(iLayer);
+
+ // check data
+ if ((dEdx <= 0.) || (timebin <= -1.)) continue;
+
+ // retrive kinematic info for this track segment
+ if(!RecalculateTrackSegmentKine(t, iLayer, mom, length)){
+ // information is not fully reliable especialy for length
+ // estimation. To be used in the future.
+ }
+
+ // this track segment has fulfilled all requierments
+ nPlanePID++;
+
+ // Get the probabilities for the different particle species
+ for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) {
+ p[iSpecies] *= pd->GetProbability(iSpecies, mom, dedx, length, iLayer);
+ //p[iSpecies] *= pd->GetProbabilityT(iSpecies, mom, timebin);
+ }
+ }
+ if(nPlanePID == 0) continue;
+
+ // normalize probabilities
+ Double_t probTotal = 0.;
+ for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) probTotal += p[iSpecies];
+ if(probTotal <= 0.){
+ AliWarning(Form("The total probability (%e) over all species <= 0 in ESD track %d."
+ , probTotal, i));
+ AliWarning("This may be caused by some error in reference data.");
+ AliWarning("Calculation continues but results might be corrupted.");
+ continue;
+ }
+ for(Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) p[iSpecies] /= probTotal;
+
+ // book PID to the track
+ t->SetTRDpid(p);
+ t->SetTRDntracklets(nPlanePID<<3);
+ }
+
+ return 0;
- AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
- if (!calibration) {
- AliErrorGeneral("AliTRDpidESD::MakePID()"
- ,"No access to calibration data");
- return -1;
- }
-
- // Retrieve the CDB container class with the probability distributions
- const AliTRDCalPIDLQ *pd = calibration->GetPIDLQObject();
- if (!pd) {
- AliErrorGeneral("AliTRDpidESD::MakePID()"
- ,"No access to AliTRDCalPIDLQ");
- return -1;
- }
-
-
- // Loop through all ESD tracks
- Double_t p[10];
- AliESDtrack *t = 0x0;
- Double_t dedx[AliTRDtrack::kNslice], dEdx;
- Int_t timebin;
- Float_t mom, length, probTotal;
- Int_t nPlanePID;
- for (Int_t i=0; i<event->GetNumberOfTracks(); i++) {
- t = event->GetTrack(i);
-
- // Check track
- if(!CheckTrack(t)) continue;
-
- // Skip tracks which have no TRD signal at all
- if (t->GetTRDsignal() == 0.) continue;
-
- // Loop over detector layers
- mom = 0.; //t->GetP();
- length = 0.;
- probTotal = 0.;
- nPlanePID = 0;
- for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) p[iSpecies] = 1.;
- for (Int_t iPlan = 0; iPlan < AliTRDgeometry::kNplan; iPlan++) {
- // read data for track segment
- for(int iSlice=0; iSlice<AliTRDtrack::kNslice; iSlice++)
- dedx[iSlice] = t->GetTRDsignals(iPlan, iSlice);
- dEdx = t->GetTRDsignals(iPlan, -1);
- timebin = t->GetTRDTimBin(iPlan);
-
- // check data
- if ((dEdx <= 0.) || (timebin <= -1.)) continue;
-
- // retrive kinematic info for this track segment
- if(!GetTrackSegmentKine(t, iPlan, mom, length)) continue;
-
- // this track segment has fulfilled all requierments
- nPlanePID++;
-
- // Get the probabilities for the different particle species
- for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) {
- p[iSpecies] *= pd->GetProbability(iSpecies, mom, dedx, length);
- p[iSpecies] *= pd->GetProbabilityT(iSpecies, mom, timebin);
- probTotal += p[iSpecies];
- }
- }
-
- // normalize probabilities
- if(probTotal > 0.)
- for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++)
- if(nPlanePID > fMinPlane) p[iSpecies] /= probTotal;
- else p[iSpecies] = 1.0;
-
-
- // book PID to the track
- t->SetTRDpid(p);
- }
-
- return 0;
}
//_____________________________________________________________________________
-Bool_t AliTRDpidESD::CheckTrack(AliESDtrack *t)
+Bool_t AliTRDpidESD::CheckTrack(AliESDtrack * const t)
{
//
// Check if track is eligible for PID calculations
//
-
- // Check the ESD track status
- if (fCheckTrackStatus) {
- if (((t->GetStatus() & AliESDtrack::kTRDout ) == 0) &&
- ((t->GetStatus() & AliESDtrack::kTRDrefit) == 0)) return kFALSE;
- }
+
+ // Check the ESD track status
+ if (fgCheckTrackStatus) {
+ if (((t->GetStatus() & AliESDtrack::kTRDout ) == 0) &&
+ ((t->GetStatus() & AliESDtrack::kTRDrefit) == 0)) return kFALSE;
+ }
- // Check for ESD kink tracks
- if (fCheckKinkStatus && (t->GetKinkIndex(0) != 0)) return kFALSE;
+ // Check for ESD kink tracks
+ if (fgCheckKinkStatus && (t->GetKinkIndex(0) != 0)) return kFALSE;
+
+ return kTRUE;
- return kTRUE;
}
//_____________________________________________________________________________
-Bool_t AliTRDpidESD::GetTrackSegmentKine(AliESDtrack *t, Int_t plan, Float_t &mom, Float_t &length)
+Bool_t AliTRDpidESD::RecalculateTrackSegmentKine(AliESDtrack * const esd
+ , Int_t layer
+ , Float_t &mom
+ , Float_t &length)
{
//
// Retrive momentum "mom" and track "length" in TRD chamber from plane
// "plan" according to information stored in AliESDtrack "t".
- //
-
- if(!gAlice){
- AliErrorGeneral("AliTRDpidESD::GetTrackSegmentKine()"
- ,"No gAlice object to retrive TRDgeometry and Magnetic fied - this has to be removed in the future.");
- return kFALSE;
- }
-
- // Retrieve TRD geometry -> Maybe there is a better way to do this
- Bool_t kSelfGeom = kFALSE;
- AliTRDgeometry *TRDgeom =0x0;
- if(gAlice) TRDgeom = AliTRDgeometry::GetGeometry(gAlice->GetRunLoader());
- if(!TRDgeom){
- AliWarningGeneral("AliTRDpidESD::GetTrackSegmentKine()", "Cannot load TRD geometry from gAlice! Build a new one.\n");
- TRDgeom = new AliTRDgeometry();
- kSelfGeom = kTRUE;
- }
- const Float_t kAmHalfWidth = AliTRDgeometry::AmThick() / 2.;
- const Float_t kDrWidth = AliTRDgeometry::DrThick();
-
-
- // retrive the magnetic field
- Double_t xyz0[3] = { 0., 0., 0.}, xyz1[3];
- Double_t b[3], alpha;
- gAlice->Field(xyz0,b); // b[] is in kilo Gauss
- Float_t field = b[2] * 0.1; // Tesla
-
-
- // find momentum at chamber entrance and track length in chamber
- AliExternalTrackParam *param = (plan<3) ? new AliExternalTrackParam(*t->GetInnerParam()) : new AliExternalTrackParam(*t->GetOuterParam());
-
- param->PropagateTo(TRDgeom->GetTime0(plan)+kAmHalfWidth, field);
- param->GetXYZ(xyz0);
- alpha = param->GetAlpha();
- param->PropagateTo(TRDgeom->GetTime0(plan)-kAmHalfWidth-kDrWidth, field);
- // eliminate track segments which are crossing SM boundaries along chamber
- if(fabs(alpha-param->GetAlpha())>.01){
- delete param;
- if(kSelfGeom) delete TRDgeom;
- return kFALSE;
- }
- param->GetXYZ(xyz1);
- length = sqrt(
- (xyz1[0]-xyz0[0])*(xyz1[0]-xyz0[0])+
- (xyz1[1]-xyz0[1])*(xyz1[1]-xyz0[1])+
- (xyz1[2]-xyz0[2])*(xyz1[2]-xyz0[2])
- );
- param->GetPxPyPz(xyz1);
- mom = sqrt(xyz1[0]*xyz1[0] + xyz1[1]*xyz1[1] + xyz1[2]*xyz1[2]);
- delete param;
- if(kSelfGeom) delete TRDgeom;
-
- return kTRUE;
-}
+ //
+ // Origin
+ // Alex Bercuci (A.Bercuci@gsi.de)
+ //
+ const Float_t kAmHalfWidth = AliTRDgeometry::AmThick() / 2.;
+ const Float_t kDrWidth = AliTRDgeometry::DrThick();
+ const Float_t kTime0 = AliTRDgeometry::GetTime0(layer);
+
+ // set initial length value to chamber height
+ length = 2 * kAmHalfWidth + kDrWidth;
+
+ // retrive track's outer param
+ const AliExternalTrackParam *op = esd->GetOuterParam();
+ if(!op){
+ mom = esd->GetP();
+ return kFALSE;
+ }
+
+ AliExternalTrackParam *param = NULL;
+ if(!fTrack){
+ fTrack = new AliExternalTrackParam(*op);
+ param = fTrack;
+ } else param = new(fTrack) AliExternalTrackParam(*op);
+
+ // retrive the magnetic field
+ Double_t xyz0[3];
+ op->GetXYZ(xyz0);
+ Float_t field = AliTracker::GetBz(xyz0); // Bz in kG at point xyz0
+ Double_t s, t;
+
+ // propagate to chamber entrance
+ if(!param->PropagateTo(kTime0-kAmHalfWidth-kDrWidth, field)){
+ mom = op->GetP();
+ s = op->GetSnp();
+ t = op->GetTgl();
+ if (s < 1.) length /= TMath::Sqrt((1.-s)*(1.+s) / (1. + t*t));
+ return kFALSE;
+ }
+ mom = param->GetP();
+ s = param->GetSnp();
+ t = param->GetTgl();
+ if (s < 1.) length /= TMath::Sqrt((1.-s)*(1.+s) / (1. + t*t));
+
+ // check if track is crossing tracking sector by propagating to chamber exit- maybe is too much :)
+ Double_t alpha = param->GetAlpha();
+ if(!param->PropagateTo(kTime0+kAmHalfWidth, field)) return kFALSE;
+
+ // mark track segments which are crossing SM boundaries along chamber
+ if(TMath::Abs(alpha-param->GetAlpha())>.01) return kFALSE;
+
+ return kTRUE;
+
+}