3 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
9 // Class to generate particles from using parametrized pT and y distributions.
10 // Distributions are obtained from pointer to object of type AliGenLib.
11 // (For example AliGenMUONlib)
13 // andreas.morsch@cern.ch
23 typedef enum { kAnalog, kNonAnalog} Weighting_t;
24 //-------------------------------------------------------------
25 class AliGenParam : public AliGenMC
29 AliGenParam(Int_t npart, const AliGenLib * Library, Int_t param, const char* tname = 0);
30 AliGenParam(Int_t npart, Int_t param, const char* tname = 0, const char* name = 0);
31 AliGenParam(Int_t npart, Int_t param,
32 Double_t (*PtPara)(const Double_t*, const Double_t*),
33 Double_t (*YPara )(const Double_t*, const Double_t*),
34 Double_t (*V2Para)(const Double_t*, const Double_t*),
35 Int_t (*IpPara)(TRandom*) );
37 virtual ~AliGenParam();
38 virtual void GenerateN(Int_t ntimes);
39 virtual void Generate();
41 // select particle type
42 virtual void SetParam(Int_t param) {fParam = param;}
43 //Setting the flag for Background transportation while using SetForceDecay()
44 void SetSelectAll(Bool_t selectall) {fSelectAll = selectall;}
46 virtual void SetWeighting(Weighting_t flag = kAnalog) {fAnalog = flag;}
47 virtual void SetDeltaPt(Float_t delta=0.01) {fDeltaPt = delta;}
48 virtual void SetDecayer(AliDecayer* decayer) {fDecayer = decayer;}
49 virtual void SetForceGammaConversion(Bool_t force=kTRUE) {fForceConv = force;}
50 virtual void Draw(const char * opt);
51 TF1 * GetPt() { return fPtPara;}
52 TF1 * GetY() {return fYPara;}
53 Float_t GetRelativeArea(Float_t ptMin, Float_t ptMax, Float_t yMin, Float_t yMax, Float_t phiMin, Float_t phiMax);
55 static double ScreenVar(double Z, double e0, double eps){ return 136/pow(Z,0.333333)*e0/eps/(1-eps); }
56 static double ScreenFunc1(double d);
57 static double ScreenFunc2(double d);
58 static double AuxScreenFunc1(double d, double Fz){ return 3*ScreenFunc1(d)-ScreenFunc2(d)-Fz; }
59 static double AuxScreenFunc2(double d, double Fz){ return 3*0.5*ScreenFunc1(d)-0.5*ScreenFunc2(d)-Fz; }
60 static TVector3 OrthogonalVector(TVector3 &inVec);
61 double EnergyFraction(double Z, double E);
62 double PolarAngle(double E);
63 Int_t ForceGammaConversion(TClonesArray *particles, Int_t nPart);
66 Double_t (*fPtParaFunc)(const Double_t*, const Double_t*); //! Pointer to Pt parametrisation function
67 Double_t (*fYParaFunc )(const Double_t*, const Double_t*); //! Pointer to Y parametrisation function
68 Int_t (*fIpParaFunc )(TRandom*); //! Pointer to particle type parametrisation function
69 Double_t (*fV2ParaFunc )(const Double_t*, const Double_t*);//! Pointer to V2 parametrisation function
70 TF1* fPtPara; // Transverse momentum parameterisation
71 TF1* fYPara; // Rapidity parameterisation
72 TF1* fV2Para; // v2 parametrization
73 TF1* fdNdPhi; // Phi distribution depending on v2
74 Int_t fParam; // Parameterisation type
75 Float_t fdNdy0; // central multiplicity per event
76 Float_t fYWgt; // Y-weight
77 Float_t fPtWgt; // Pt-weight
78 Float_t fBias; // Biasing factor
79 Int_t fTrials; // Number of trials
80 Float_t fDeltaPt; // pT sampling in steps of fDeltaPt
81 Bool_t fSelectAll; // Flag for transportation of Background while using SetForceDecay()
82 AliDecayer *fDecayer; // ! Pointer to pythia object for decays
86 AliGenParam(const AliGenParam &Param);
87 AliGenParam & operator=(const AliGenParam & rhs);
89 ClassDef(AliGenParam, 2) // Generator using parameterised pt- and y-distribution