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1 | #ifndef ALIMUONTRACKEXTRAP_H | |
2 | #define ALIMUONTRACKEXTRAP_H | |
3 | /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
4 | * See cxx source for full Copyright notice */ | |
5 | ||
6 | /*$Id$*/ | |
7 | // Revision of includes 07/05/2004 | |
8 | ||
9 | /// \ingroup rec | |
10 | /// \class AliMUONTrackExtrap | |
11 | /// \brief Track parameters in ALICE dimuon spectrometer | |
12 | /// | |
13 | ////////////////////////////////////////////////////////////// | |
14 | /// Tools for track extrapolation in ALICE dimuon spectrometer | |
15 | ////////////////////////////////////////////////////////////// | |
16 | ||
17 | #include <TObject.h> | |
18 | #include <TMatrixD.h> | |
19 | ||
20 | class AliMagF; | |
21 | class AliMUONTrackParam; | |
22 | ||
23 | class AliMUONTrackExtrap : public TObject | |
24 | { | |
25 | public: | |
26 | /// Constructor | |
27 | AliMUONTrackExtrap() : TObject(){}; | |
28 | /// Destructor | |
29 | virtual ~AliMUONTrackExtrap(){}; | |
30 | ||
31 | static void SetField(); | |
32 | ||
33 | /// return kTRUE if the field is switched ON | |
34 | static Bool_t IsFieldON() {return fgFieldON;} | |
35 | ||
36 | static Double_t GetImpactParamFromBendingMomentum(Double_t bendingMomentum); | |
37 | static Double_t GetBendingMomentumFromImpactParam(Double_t impactParam); | |
38 | ||
39 | // Linearly extrapolate track parameters | |
40 | static void LinearExtrapToZ(AliMUONTrackParam* trackParam, Double_t zEnd); | |
41 | ||
42 | // Linearly extrapolate track parameters and covariances | |
43 | static void LinearExtrapToZCov(AliMUONTrackParam* trackParam, Double_t zEnd, Bool_t updatePropagator = kFALSE); | |
44 | ||
45 | // Extrapolate track parameters in magnetic field | |
46 | static Bool_t ExtrapToZ(AliMUONTrackParam *trackParam, Double_t zEnd); | |
47 | ||
48 | // Extrapolate track parameters and covariances in magnetic field | |
49 | static Bool_t ExtrapToZCov(AliMUONTrackParam* trackParam, Double_t zEnd, Bool_t updatePropagator = kFALSE); | |
50 | ||
51 | // Extrapolate track parameters to vertex, corrected for multiple scattering and energy loss effects | |
52 | // Add branson correction resolution and energy loss fluctuation to parameter covariances | |
53 | static void ExtrapToVertex(AliMUONTrackParam* trackParam, | |
54 | Double_t xVtx, Double_t yVtx, Double_t zVtx, | |
55 | Double_t errXVtx, Double_t errYVtx); | |
56 | ||
57 | // Extrapolate track parameters to vertex, corrected for multiple scattering effects only | |
58 | // Add branson correction resolution to parameter covariances | |
59 | static void ExtrapToVertexWithoutELoss(AliMUONTrackParam* trackParam, | |
60 | Double_t xVtx, Double_t yVtx, Double_t zVtx, | |
61 | Double_t errXVtx, Double_t errYVtx); | |
62 | ||
63 | // Extrapolate track parameters to vertex, corrected for energy loss effects only | |
64 | // Add dispersion due to multiple scattering and energy loss fluctuation to parameter covariances | |
65 | static void ExtrapToVertexWithoutBranson(AliMUONTrackParam* trackParam, Double_t zVtx); | |
66 | ||
67 | // Extrapolate track parameters to vertex without multiple scattering and energy loss corrections | |
68 | // Add dispersion due to multiple scattering to parameter covariances | |
69 | static void ExtrapToVertexUncorrected(AliMUONTrackParam* trackParam, Double_t zVtx); | |
70 | ||
71 | static Double_t TotalMomentumEnergyLoss(AliMUONTrackParam* trackParam, Double_t xVtx, Double_t yVtx, Double_t zVtx); | |
72 | ||
73 | static Double_t GetMCSAngle2(const AliMUONTrackParam& param, Double_t dZ, Double_t x0); | |
74 | static void AddMCSEffect(AliMUONTrackParam *param, Double_t dZ, Double_t x0); | |
75 | ||
76 | static Bool_t ExtrapOneStepRungekutta(Double_t charge, Double_t step, const Double_t* vect, Double_t* vout); | |
77 | ||
78 | ||
79 | private: | |
80 | static const Double_t fgkSimpleBPosition; //!< position of the dipole | |
81 | static const Double_t fgkSimpleBLength; //!< length of the dipole | |
82 | static Double_t fgSimpleBValue; //!< magnetic field value at the centre | |
83 | static Bool_t fgFieldON; //!< kTRUE if the field is switched ON | |
84 | static const Bool_t fgkUseHelix; //!< Tell whether to use Helix or not (default is Runge-Kutta) | |
85 | static const Int_t fgkMaxStepNumber; //!< Maximum number of steps for track extrapolation | |
86 | static const Double_t fgkHelixStepLength; //!< Step lenght for track extrapolation (used in Helix) | |
87 | static const Double_t fgkRungeKuttaMaxResidue;//!< Maximal distance (in Z) to destination to stop the track extrapolation (used in Runge-Kutta) | |
88 | ||
89 | // Functions | |
90 | ||
91 | /// Not implemented | |
92 | AliMUONTrackExtrap(const AliMUONTrackExtrap& trackExtrap); | |
93 | /// Not implemented | |
94 | AliMUONTrackExtrap& operator=(const AliMUONTrackExtrap& trackExtrap); | |
95 | ||
96 | static Bool_t ExtrapToZHelix(AliMUONTrackParam *trackParam, Double_t Z); | |
97 | static Bool_t ExtrapToZRungekutta(AliMUONTrackParam *trackParam, Double_t Z); | |
98 | ||
99 | static void ConvertTrackParamForExtrap(AliMUONTrackParam* trackParam, Double_t forwardBackward, Double_t *v3); | |
100 | static void RecoverTrackParam(Double_t *v3, Double_t Charge, AliMUONTrackParam* trackParam); | |
101 | ||
102 | static void ExtrapToVertex(AliMUONTrackParam* trackParam, | |
103 | Double_t xVtx, Double_t yVtx, Double_t zVtx, | |
104 | Double_t errXVtx, Double_t errYVtx, | |
105 | Bool_t correctForMCS, Bool_t correctForEnergyLoss); | |
106 | ||
107 | static void AddMCSEffectInAbsorber(AliMUONTrackParam* trackParam, Double_t signedPathLength, Double_t f0, Double_t f1, Double_t f2); | |
108 | static void CorrectMCSEffectInAbsorber(AliMUONTrackParam* param, | |
109 | Double_t xVtx, Double_t yVtx, Double_t zVtx, | |
110 | Double_t errXVtx, Double_t errYVtx, | |
111 | Double_t absZBeg, Double_t pathLength, Double_t f0, Double_t f1, Double_t f2); | |
112 | static void CorrectELossEffectInAbsorber(AliMUONTrackParam* param, Double_t eLoss, Double_t sigmaELoss2); | |
113 | static Bool_t GetAbsorberCorrectionParam(Double_t trackXYZIn[3], Double_t trackXYZOut[3], Double_t pTotal, | |
114 | Double_t &pathLength, Double_t &f0, Double_t &f1, Double_t &f2, | |
115 | Double_t &meanRho, Double_t &totalELoss, Double_t &sigmaELoss2); | |
116 | ||
117 | static Double_t BetheBloch(Double_t pTotal, Double_t pathLength, Double_t rho, Double_t atomicZ, Double_t atomicZoverA); | |
118 | static Double_t EnergyLossFluctuation2(Double_t pTotal, Double_t pathLength, Double_t rho, Double_t atomicZoverA); | |
119 | ||
120 | static void Cov2CovP(const TMatrixD ¶m, TMatrixD &cov); | |
121 | static void CovP2Cov(const TMatrixD ¶m, TMatrixD &cov); | |
122 | ||
123 | static void ExtrapOneStepHelix(Double_t charge, Double_t step, const Double_t *vect, Double_t *vout); | |
124 | static void ExtrapOneStepHelix3(Double_t field, Double_t step, const Double_t *vect, Double_t *vout); | |
125 | ||
126 | ClassDef(AliMUONTrackExtrap, 0) // Tools for track extrapolation in ALICE dimuon spectrometer | |
127 | }; | |
128 | ||
129 | #endif |