1 #ifndef ALIVERTEXERTRACKS_H
2 #define ALIVERTEXERTRACKS_H
3 /* Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
7 //-------------------------------------------------------
8 // Class for vertex determination with ESD tracks
10 // Origin: AliITSVertexerTracks
11 // A.Dainese, Padova, andrea.dainese@pd.infn.it
12 // M.Masera, Torino, massimo.masera@to.infn.it
13 // Moved to STEER and adapted to ESD tracks:
14 // F.Prino, Torino, prino@to.infn.it
15 //-------------------------------------------------------
17 /*****************************************************************************
19 * This class determines the vertex of a set of ESD tracks. *
20 * Different algorithms are implemented, see data member fAlgo. *
22 *****************************************************************************/
24 #include "AliESDVertex.h"
25 #include "AliESDtrack.h"
28 #include <TObjArray.h>
34 class AliVertexerTracks : public TObject {
38 AliVertexerTracks(Double_t fieldkG);
39 virtual ~AliVertexerTracks();
41 AliESDVertex* FindPrimaryVertex(const AliESDEvent *esdEvent);
42 AliESDVertex* VertexForSelectedTracks(TTree *trkTree,Bool_t optUseFitter=kTRUE, Bool_t optPropagate=kTRUE);
43 AliESDVertex* VertexForSelectedTracks(TObjArray *trkArray, Bool_t optUseFitter=kTRUE, Bool_t optPropagate=kTRUE);
44 AliESDVertex* RemoveTracksFromVertex(AliESDVertex *inVtx,TTree *trksTree,Float_t *diamondxy);
45 void SetConstraintOff() { fConstraint=kFALSE; return; }
46 void SetConstraintOn() { fConstraint=kTRUE; return; }
47 void SetDebug(Int_t optdebug=0) { fDebug=optdebug; return; }
48 void SetDCAcut(Double_t maxdca) { fDCAcut=maxdca; return; }
49 void SetFinderAlgorithm(Int_t opt=1) { fAlgo=opt; return; }
50 void SetITSRequired() { fITSin=kTRUE; return; }
51 void SetITSrefitRequired() { fITSin=kTRUE;fITSrefit=kTRUE; return; }
52 void SetITSNotRequired() { fITSrefit=kFALSE;fITSin=kFALSE; return; }
53 void SetITSrefitNotRequired() { fITSrefit=kFALSE; return; }
54 void SetMaxd0z0(Double_t maxd0z0=0.5) { fMaxd0z0=maxd0z0; return; }
55 void SetMinITSClusters(Int_t n=5) { fMinITSClusters = n; return; }
56 void SetMinTracks(Int_t n=1) { fMinTracks = n; return; }
57 void SetNSigmad0(Double_t n=3) { fNSigma=n; return; }
58 Double_t GetNSigmad0() const { return fNSigma; }
59 void SetOnlyFitter() { if(!fConstraint) AliFatal("Set constraint first!");
60 fOnlyFitter=kTRUE; return; }
61 void SetSkipTracks(Int_t n,Int_t *skipped);
62 void SetVtxStart(Double_t x=0,Double_t y=0,Double_t z=0)
63 { fNominalPos[0]=x; fNominalPos[1]=y; fNominalPos[2]=z; return; }
64 void SetVtxStartSigma(Double_t sx=3.,Double_t sy=3.,Double_t sz=15.)
65 { fNominalCov[0]=sx*sx; fNominalCov[2]=sy*sy; fNominalCov[5]=sz*sz;
66 fNominalCov[1]=0.; fNominalCov[3]=0.; fNominalCov[4]=0.; return; }
67 void SetVtxStart(AliESDVertex *vtx);
68 static Double_t GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0);
69 static Double_t GetDeterminant3X3(Double_t matr[][3]);
70 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d);
71 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d);
72 static AliESDVertex TrackletVertexFinder(TClonesArray *lines, Int_t optUseWeights=0);
73 void SetFieldkG(Double_t field=-999.) { fFieldkG=field; return; }
74 Double_t GetFieldkG() const {
75 if(fFieldkG<-99.) AliFatal("Field value not set");
77 void SetNSigmaForUi00(Double_t n=1.5) { fnSigmaForUi00=n; return; }
78 Double_t GetNSigmaForUi00() const { return fnSigmaForUi00; }
81 void HelixVertexFinder();
82 void OneTrackVertFinder();
83 Int_t PrepareTracks(TTree &trkTree,Int_t optImpParCut);
84 Bool_t TrackToPoint(AliESDtrack *t,
85 TMatrixD &ri,TMatrixD &wWi,
86 Bool_t uUi3by3=kFALSE) const;
87 void VertexFinder(Int_t optUseWeights=0);
88 void VertexFitter(Bool_t useConstraint=kFALSE);
89 void StrLinVertexFinderMinDist(Int_t optUseWeights=0);
90 void TooFewTracks(const AliESDEvent *esdEvent);
92 AliESDVertex fVert; // vertex after vertex finder
93 AliESDVertex *fCurrentVertex; // ESD vertex after fitter
94 Double_t fFieldkG; // z component of field (kGauss)
95 Double_t fNominalPos[3]; // initial knowledge on vertex position
96 Double_t fNominalCov[6]; // initial knowledge on vertex position
97 Bool_t fConstraint; // true when "mean vertex" was set in
98 // fNominal ... and must be used in the fit
99 Bool_t fOnlyFitter; // primary with one fitter shot only
100 // (use only with beam constraint)
101 Int_t fMinTracks; // minimum number of tracks
102 Int_t fMinITSClusters; // minimum number of ITS clusters per track
103 TObjArray fTrkArray; // array with tracks to be processed
104 Int_t *fTrksToSkip; // tracks to be skipped for find and fit
105 Int_t fNTrksToSkip; // number of tracks to be skipped
106 Double_t fDCAcut; // maximum DCA between 2 tracks used for vertex
107 Int_t fAlgo; // option for vertex finding algorythm
108 Double_t fNSigma; // number of sigmas for d0 cut in PrepareTracks()
109 Double_t fMaxd0z0; // value [mm] for sqrt(d0d0+z0z0) cut
110 // in PrepareTracks(1) if fConstraint=kFALSE
111 Bool_t fITSin; // if kTRUE (default), use only kITSin tracks
112 // if kFALSE, use all tracks (also TPC only)
113 Bool_t fITSrefit; // if kTRUE (default), use only kITSrefit tracks
114 // if kFALSE, use all tracks (also TPC only)
115 Double_t fnSigmaForUi00; // n. sigmas from finder in TrackToPoint
116 Int_t fDebug; //! debug flag - verbose printing if >0
117 // fAlgo=1 (default) finds minimum-distance point among all selected tracks
118 // approximated as straight lines
119 // and uses errors on track parameters as weights
120 // fAlgo=2 finds minimum-distance point among all the selected tracks
121 // approximated as straight lines
122 // fAlgo=3 finds the average point among DCA points of all pairs of tracks
123 // treated as helices
124 // fAlgo=4 finds the average point among DCA points of all pairs of tracks
125 // approximated as straight lines
126 // and uses errors on track parameters as weights
127 // fAlgo=5 finds the average point among DCA points of all pairs of tracks
128 // approximated as straight lines
132 AliVertexerTracks(const AliVertexerTracks & source);
133 AliVertexerTracks & operator=(const AliVertexerTracks & source);
135 ClassDef(AliVertexerTracks,9) // 3D Vertexing with ESD tracks