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 "AliTracker.h"
28 #include <TObjArray.h>
33 class AliVertexerTracks : public TObject {
37 AliVertexerTracks(Double_t xStart, Double_t yStart);
38 virtual ~AliVertexerTracks();
41 // computes the vertex from the set of tracks in the tree
42 AliVertex* VertexForSelectedTracks(TTree *trkTree);
43 AliVertex* VertexForSelectedTracks(TObjArray *trkArray);
44 AliESDVertex* FindPrimaryVertex(const AliESD *esdEvent);
45 AliESDVertex* FindPrimaryVertexOld(const AliESD *esdEvent);
46 void SetMinTracks(Int_t n=2) { fMinTracks = n; return; }
47 void SetMinITSClusters(Int_t n=5) { fMinITSClusters = n; return; }
48 void SetSkipTracks(Int_t n,Int_t *skipped);
49 void SetDebug(Int_t optdebug=0) {fDebug=optdebug;}
50 void SetVtxStart(Double_t x=0,Double_t y=0,Double_t z=0)
51 { fNominalPos[0]=x; fNominalPos[1]=y; fNominalPos[2]=z; return; }
52 void SetVtxStartSigma(Double_t sx=3,Double_t sy=3,Double_t sz=6)
53 { fNominalSigma[0]=sx; fNominalSigma[1]=sy; fNominalSigma[2]=sz; return; }
54 void SetVtxStart(AliESDVertex *vtx)
55 { SetVtxStart(vtx->GetXv(),vtx->GetYv(),vtx->GetZv());
56 SetVtxStartSigma(vtx->GetXRes(),vtx->GetYRes(),vtx->GetZRes()); return; }
57 void SetDCAcut(Double_t maxdca)
58 { fDCAcut=maxdca; return;}
59 void SetFinderAlgorithm(Int_t opt=1)
61 void SetNSigmad0(Double_t n=3)
62 { fNSigma=n; return; }
63 static Double_t GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0);
64 static Double_t GetDeterminant3X3(Double_t matr[][3]);
65 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d);
66 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d);
69 Double_t GetField() const { return AliTracker::GetBz();}
70 Int_t PrepareTracks(TTree &trkTree, Int_t OptImpParCut);
71 Double_t Sigmad0rphi(Double_t pt) const;
72 void VertexFinder(Int_t optUseWeights=0);
73 void HelixVertexFinder();
74 void StrLinVertexFinderMinDist(Int_t OptUseWeights=0);
75 void VertexFitter(Bool_t useNominaVtx=kFALSE);
76 void TooFewTracks(const AliESD *esdEvent);
79 AliVertex fVert; // vertex after vertex finder
80 AliESDVertex *fCurrentVertex; // ESD vertex after fitter
81 Double_t fNominalPos[3]; // initial knowledge on vertex position
82 Double_t fNominalSigma[3]; // initial knowledge on vertex position
83 Int_t fMinTracks; // minimum number of tracks
84 Int_t fMinITSClusters; // minimum number of ITS clusters per track
85 TObjArray fTrkArray; // array with tracks to be processed
86 Int_t *fTrksToSkip; // tracks to be skipped for find and fit
87 Int_t fNTrksToSkip; // number of tracks to be skipped
88 Double_t fDCAcut; // maximum DCA between 2 tracks used for vertex
89 Int_t fAlgo; // option for vertex finding algorythm
90 Double_t fNSigma; // number of sigmas for d0 cut in PrepareTracks()
91 Int_t fDebug; //! debug flag - verbose printing if >0
92 // fAlgo=1 (default) finds minimum-distance point among all selected tracks
93 // approximated as straight lines
94 // and uses errors on track parameters as weights
95 // fAlgo=2 finds minimum-distance point among all the selected tracks
96 // approximated as straight lines
97 // fAlgo=3 finds the average point among DCA points of all pairs of tracks
99 // fAlgo=4 finds the average point among DCA points of all pairs of tracks
100 // approximated as straight lines
101 // and uses errors on track parameters as weights
102 // fAlgo=5 finds the average point among DCA points of all pairs of tracks
103 // approximated as straight lines
106 AliVertexerTracks(const AliVertexerTracks & source);
107 AliVertexerTracks & operator=(const AliVertexerTracks & source);
109 ClassDef(AliVertexerTracks,4) // 3D Vertexing with ESD tracks