+
+AliESDtrackCuts* AliESDtrackCuts::GetMultEstTrackCuts(MultEstTrackCuts cut)
+{
+ // returns the multiplicity estimator track cuts objects to allow for user configuration
+ // upon first call the objects are created
+ //
+ // the cut defined here correspond to GetStandardITSTPCTrackCuts2010 (apart from the one for without SPD)
+
+ if (!fgMultEstTrackCuts[kMultEstTrackCutGlobal])
+ {
+ // quality cut on ITS+TPC tracks
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal] = new AliESDtrackCuts();
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal]->SetMinNClustersTPC(70);
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal]->SetMaxChi2PerClusterTPC(4);
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal]->SetAcceptKinkDaughters(kFALSE);
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal]->SetRequireTPCRefit(kTRUE);
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal]->SetRequireITSRefit(kTRUE);
+ //multiplicity underestimate if we use global tracks with |eta| > 0.9
+ fgMultEstTrackCuts[kMultEstTrackCutGlobal]->SetEtaRange(-0.9, 0.9);
+
+ // quality cut on ITS_SA tracks (complementary to ITS+TPC)
+ fgMultEstTrackCuts[kMultEstTrackCutITSSA] = new AliESDtrackCuts();
+ fgMultEstTrackCuts[kMultEstTrackCutITSSA]->SetRequireITSRefit(kTRUE);
+
+ // primary selection for tracks with SPD hits
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD] = new AliESDtrackCuts();
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD]->SetClusterRequirementITS(AliESDtrackCuts::kSPD, AliESDtrackCuts::kAny);
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD]->SetMaxDCAToVertexXYPtDep("0.0182+0.0350/pt^1.01");
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD]->SetMaxDCAToVertexZ(2);
+
+ // primary selection for tracks w/o SPD hits
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD] = new AliESDtrackCuts();
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD]->SetClusterRequirementITS(AliESDtrackCuts::kSPD, AliESDtrackCuts::kNone);
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD]->SetMaxDCAToVertexXYPtDep("1.5*(0.0182+0.0350/pt^1.01)");
+ fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD]->SetMaxDCAToVertexZ(2);
+ }
+
+ return fgMultEstTrackCuts[cut];
+}
+
+Int_t AliESDtrackCuts::GetReferenceMultiplicity(const AliESDEvent* esd, MultEstTrackType trackType, Float_t etaRange)
+{
+ // Get multiplicity estimate based on TPC/ITS tracks and tracklets
+ // Adapted for AliESDtrackCuts from a version developed by: Ruben Shahoyan, Anton Alkin, Arvinder Palaha
+ //
+ // Returns a negative value if no reliable estimate can be provided:
+ // -1 SPD vertex missing
+ // -2 SPD VertexerZ dispersion too large
+ // -3 Track vertex missing (not checked for kTracklets)
+ // -4 Distance between SPD and track vertices too large (not checked for kTracklets)
+ //
+ // WARNING This functions does not cut on the z vtx. Depending on the eta range requested, you need to restrict your z vertex range!
+ //
+ // Strategy for combined estimators
+ // 1. Count global tracks and flag them
+ // 2. Count ITSSA as complementaries for ITSTPC+ or as main tracks
+ // 3. Count the complementary SPD tracklets
+
+ const AliESDVertex* vertices[2];
+ vertices[0] = esd->GetPrimaryVertexSPD();
+ vertices[1] = esd->GetPrimaryVertexTracks();
+
+ if (!vertices[0]->GetStatus())
+ {
+ AliDebugClass(AliLog::kDebug, "No SPD vertex. Not able to make a reliable multiplicity estimate.");
+ return -1;
+ }
+
+ if (vertices[0]->IsFromVertexerZ() && vertices[0]->GetDispersion() > 0.02)
+ {
+ AliDebugClass(AliLog::kDebug, "Vertexer z dispersion > 0.02. Not able to make a reliable multiplicity estimate.");
+ return -2;
+ }
+
+ Int_t multiplicityEstimate = 0;
+
+ // SPD tracklet-only estimate
+ if (trackType == kTracklets)
+ {
+ const AliMultiplicity* spdmult = esd->GetMultiplicity(); // spd multiplicity object
+ for (Int_t i=0; i<spdmult->GetNumberOfTracklets(); ++i)
+ {
+ if (TMath::Abs(spdmult->GetEta(i)) > etaRange)
+ continue; // eta selection for tracklets
+ multiplicityEstimate++;
+ }
+ return multiplicityEstimate;
+ }
+
+ if (!vertices[1]->GetStatus())
+ {
+ AliDebugClass(AliLog::kDebug, "No track vertex. Not able to make a reliable multiplicity estimate.");
+ return -3;
+ }
+
+ // TODO value of displacement to be studied
+ const Float_t maxDisplacement = 0.5;
+ //check for displaced vertices
+ Double_t displacement = TMath::Abs(vertices[0]->GetZ() - vertices[1]->GetZ());
+ if (displacement > maxDisplacement)
+ {
+ AliDebugClass(AliLog::kDebug, Form("Displaced vertices %f > %f",displacement,maxDisplacement));
+ return -4;
+ }
+
+ // update eta range in track cuts
+ GetMultEstTrackCuts(kMultEstTrackCutITSSA)->SetEtaRange(-etaRange, etaRange);
+ GetMultEstTrackCuts(kMultEstTrackCutDCAwSPD)->SetEtaRange(-etaRange, etaRange);
+ GetMultEstTrackCuts(kMultEstTrackCutDCAwoSPD)->SetEtaRange(-etaRange, etaRange);
+
+ //*******************************************************************************************************
+ //set counters to initial zeros
+ Int_t tracksITSTPC = 0; //number of global tracks for a given event
+ Int_t tracksITSSA = 0; //number of ITS standalone tracks for a given event
+ Int_t tracksITSTPCSA_complementary = 0; //number of ITS standalone tracks complementary to TPC for a given event
+ Int_t trackletsITSTPC_complementary = 0;//number of SPD tracklets complementary to global/ITSSA tracks for a given events
+ Int_t trackletsITSSA_complementary = 0; //number of SPD tracklets complementary to ITSSA tracks for a given event
+
+ const Int_t nESDTracks = esd->GetNumberOfTracks();
+ Int_t highestID = 0;
+
+ // flags for secondary and rejected tracks
+ const Int_t kRejBit = BIT(15); // set this bit in global tracks if it is rejected by a cut
+ const Int_t kSecBit = BIT(16); // set this bit in global tracks if it is secondary according to a cut
+
+ for(Int_t itracks=0; itracks < nESDTracks; itracks++) {
+ if(esd->GetTrack(itracks)->GetLabel() > highestID) highestID = esd->GetTrack(itracks)->GetLabel();
+ esd->GetTrack(itracks)->ResetBit(kSecBit|kRejBit); //reset bits used for flagging secondaries and rejected tracks in case they were changed before this analysis
+ }
+ const Int_t maxid = highestID+1; // used to define bool array for check multiple associations of tracklets to one track. array starts at 0.
+
+ // bit mask for esd tracks, to check if multiple tracklets are associated to it
+ Bool_t globalBits[maxid], pureITSBits[maxid];
+ for(Int_t i=0; i<maxid; i++){ // set all bools to false
+ globalBits[i]=kFALSE;
+ pureITSBits[i]=kFALSE;
+ }
+
+ //*******************************************************************************************************
+ // get multiplicity from global tracks
+ for(Int_t itracks = 0; itracks < nESDTracks; itracks++) { // flag the tracks
+ AliESDtrack* track = esd->GetTrack(itracks);
+
+ // if track is a secondary from a V0, flag as a secondary
+ if (track->IsOn(AliESDtrack::kMultInV0)) {
+ track->SetBit(kSecBit);
+ continue;
+ }
+
+ //secondary?
+ if (track->IsOn(AliESDtrack::kMultSec)) {
+ track->SetBit(kSecBit);
+ continue;
+ }
+
+ // check tracks with ITS part
+ //*******************************************************************************************************
+ if (track->IsOn(AliESDtrack::kITSin) && !track->IsOn(AliESDtrack::kITSpureSA) && trackType == kTrackletsITSTPC) { // track has ITS part but is not an ITS_SA
+ //*******************************************************************************************************
+ // TPC+ITS
+ if (track->IsOn(AliESDtrack::kTPCin)) { // Global track, has ITS and TPC contributions
+ if (fgMultEstTrackCuts[kMultEstTrackCutGlobal]->AcceptTrack(track)) { // good ITSTPC track
+ if (fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD]->AcceptTrack(track) || fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD]->AcceptTrack(track)) {
+ tracksITSTPC++; //global track counted
+ globalBits[itracks] = kTRUE;
+ }
+ else track->SetBit(kSecBit); // large DCA -> secondary, don't count either track not associated tracklet
+ }
+ else track->SetBit(kRejBit); // bad quality, don't count the track, but may count tracklet if associated
+ }
+ //*******************************************************************************************************
+ // ITS complementary
+ else if (fgMultEstTrackCuts[kMultEstTrackCutITSSA]->AcceptTrack(track)) { // good ITS complementary track
+ if (fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD]->AcceptTrack(track) || fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD]->AcceptTrack(track)) {
+ tracksITSTPCSA_complementary++;
+ globalBits[itracks] = kTRUE;
+ }
+ else track->SetBit(kSecBit); // large DCA -> secondary, don't count either track not associated tracklet
+ }
+ else track->SetBit(kRejBit); // bad quality, don't count the track, but may count tracklet if associated
+ }
+ //*******************************************************************************************************
+ // check tracks from ITS_SA_PURE
+ if (track->IsOn(AliESDtrack::kITSin) && track->IsOn(AliESDtrack::kITSpureSA) && trackType == kTrackletsITSSA){
+ if (fgMultEstTrackCuts[kMultEstTrackCutITSSA]->AcceptTrack(track)) { // good ITSSA track
+ if (fgMultEstTrackCuts[kMultEstTrackCutDCAwSPD]->AcceptTrack(track) || fgMultEstTrackCuts[kMultEstTrackCutDCAwoSPD]->AcceptTrack(track)) {
+ tracksITSSA++;
+ pureITSBits[itracks] = kTRUE;
+ }
+ else track->SetBit(kRejBit);
+ }
+ else track->SetBit(kRejBit);
+ }
+ }//ESD tracks counted
+
+ //*******************************************************************************************************
+ // get multiplicity from ITS tracklets to complement TPC+ITS, and ITSpureSA
+ const AliMultiplicity* spdmult = esd->GetMultiplicity(); // spd multiplicity object
+ for (Int_t i=0; i<spdmult->GetNumberOfTracklets(); ++i) {
+ if (TMath::Abs(spdmult->GetEta(i)) > etaRange) continue; // eta selection for tracklets
+
+ // if counting tracks+tracklets, check if clusters were already used in tracks
+ Int_t id1,id2,id3,id4;
+ spdmult->GetTrackletTrackIDs(i,0,id1,id2); // references for eventual Global/ITS_SA tracks
+ AliESDtrack* tr1 = id1>=0 ? esd->GetTrack(id1) : 0;
+ spdmult->GetTrackletTrackIDs(i,1,id3,id4); // references for eventual ITS_SA_pure tracks
+ AliESDtrack* tr3 = id3>=0 ? esd->GetTrack(id3) : 0;
+
+ // are both clusters from the same tracks? If not, skip the tracklet (shouldn't change things much)
+ if ((id1!=id2 && id1>=0 && id2>=0) || (id3!=id4 && id3>=0 && id4>=0)) continue;
+
+ Bool_t bUsedInGlobal = (id1 != -1) ? globalBits[id1] : 0;// has associated global track been associated to a previous tracklet?
+ Bool_t bUsedInPureITS = (id3 != -1) ? pureITSBits[id3] : 0;// has associated pure ITS track been associated to a previous tracklet?
+ //*******************************************************************************************************
+ if (trackType == kTrackletsITSTPC) {
+ // count tracklets towards global+complementary tracks
+ if ( (tr1 && !tr1->TestBit(kSecBit)) && // reject as secondary
+ (tr1 && tr1->TestBit(kRejBit)) ) { // count tracklet as bad quality track
+ if(!bUsedInGlobal){
+ ++trackletsITSTPC_complementary;
+ if(id1>0) globalBits[id1] = kTRUE; // mark global track linked to this tracklet as "associated"
+ }
+ }
+ else if(id1<0) {
+ ++trackletsITSTPC_complementary; // if no associated track, count the tracklet
+ }
+ } else {
+ // count tracklets towards ITS_SA_pure tracks
+ if ( (tr3 && !tr3->TestBit(kSecBit)) && // reject as secondary
+ (tr3 && tr3->TestBit(kRejBit)) ) { // count tracklet as bad quality track
+ if(!bUsedInPureITS) {
+ ++trackletsITSSA_complementary;
+ if(id3>0) pureITSBits[id3] = kTRUE; // mark global track linked to this tracklet as "associated"
+ }
+ }
+ else if(id3<0) {
+ ++trackletsITSSA_complementary; // if no associated track, count the tracklet
+ }
+ }
+ }
+
+ //*******************************************************************************************************
+ if (trackType == kTrackletsITSTPC)
+ multiplicityEstimate = tracksITSTPC + tracksITSTPCSA_complementary + trackletsITSTPC_complementary;
+ else
+ multiplicityEstimate = tracksITSSA + trackletsITSSA_complementary;
+
+ return multiplicityEstimate;
+}