3 //_________________________________________________________________
4 ///////////////////////////////////////////////////////////////////////
6 // class AliHBTLLWeights
8 // This class introduces the weight's calculation
9 // according to the Lednicky's algorithm.
10 // The detailed description of the algorithm can be found
11 // in comments to fortran code:
14 // Source simulation: Particle position/distance randomization
15 // This class has functionality of randomizing particle positions / pair distances
16 // so obtained correlation function follows a given shape,
17 // depending on a value of fRandomPosition member
18 // By default this feature is switched off: fRandomPosition == AliHBTLLWeights::kNone
19 // It can be: kGaussianQInv - so 1D Qinv correlation function has a Gaussian shape
20 // (and also Qlong and Qside, but not Qout)
21 // kGaussianOSL - so 3D Qout-Qside-Qlong correlation function has a Gaussian shape
23 // Ludmila Malinina, Piotr Krzysztof Skowronski
25 ///////////////////////////////////////////////////////////////////////
27 #ifndef ALIHBTLLWEIGHTS_H
28 #define ALIHBTLLWEIGHTS_H
30 #include "AliHBTWeights.h"
33 class AliVAODParticle;
34 class AliHBTLLWeights: public AliHBTWeights
38 virtual ~AliHBTLLWeights(){;}
39 static AliHBTLLWeights* Instance();
43 Double_t GetWeight(AliHBTPair* partpair); //get weight calculated by Lednicky's algorithm
45 void Init(); //put the initial values in fortran commons fsiini, led_bldata
46 void SetTest(Bool_t rtest = kTRUE);//Sets fTest member
48 void SetColoumb(Bool_t col = kTRUE);//: (ICH in fortran code) Coulomb interaction between the two particles ON (OFF)
49 void SetQuantumStatistics(Bool_t qss = kTRUE);//IQS: quantum statistics for the two particles ON (OFF) //if non-identical particles automatically off
50 void SetStrongInterSwitch(Bool_t sis = kTRUE);//ISI: strong interaction between the two particles ON (OFF)
51 void SetColWithResidNuclSwitch(Bool_t crn = kTRUE);//I3C: Coulomb interaction with residual nucleus ON (OFF)
52 void SetLambda(Double_t la){fOneMinusLambda=1.-la;} //lambda=haoticity
53 void SetApproxModel(Int_t ap);//sets Model of Approximation (NS in Fortran code)
54 void SetParticlesTypes(Int_t pid1, Int_t pid2); //set AliRoot particles types
55 void SetNucleusCharge(Double_t ch); // not used now (see comments in fortran code)
56 void SetNucleusMass(Double_t mass); // (see comments in fortran code)
58 enum ERandomizationWay {kNone = 0, kGaussianQInv, kGaussianOSL};
60 void SetRandomPosition(ERandomizationWay rw = kNone); //Choose if, and if yes, how to randomize distance between particles
61 void SetR1dw(Double_t R); //spherical source model radii
65 Bool_t fTest; //flag indicating if parameters listed below are to be calculated automatically (0)
67 Bool_t fColoumbSwitch; //switches on/off Coulumb effect
68 Bool_t fQuantStatSwitch; //switches on/off Quantum Statistics effect
69 Bool_t fStrongInterSwitch;//Switches strong interactions TRUE=ON
70 Bool_t fColWithResidNuclSwitch;//Switches couloumb interaction
71 //with residual nucleus TRUE=ON
72 Double_t fNuclMass; //mass of nucleus
73 Double_t fNuclCharge; //charge of nucleus
75 ERandomizationWay fRandomPosition;//flag indicating if positions of particles shuold be randomized according to parameters below
76 Double_t fRadius; //radius used for randomizing particle vertex position
78 Double_t fOneMinusLambda; //1 - intercept parameter
80 Int_t fApproximationModel; //approximation used to calculate Bethe-Salpeter amplitude see SetApproxModel for more comments
82 Int_t fPID1; //Pdg Code of the first particle in the pair
83 Int_t fPID2; //Pdg Code of the second particle in the pair
84 Double_t fSigma; //constants for spherical source model in cm
85 static const Double_t fgkWcons; //constant for fm->GeV conversion 1/0.1973
87 static AliHBTLLWeights *fgLLWeights;// pointer to wrapper of Fortran Lednicky code
89 static Int_t GetPairCode(Int_t pid1,Int_t pid2);
90 static Int_t GetPairCode(const AliHBTPair* partpair);//calculate automatically internal code
93 AliHBTLLWeights(const AliHBTLLWeights &/*source*/);
94 AliHBTLLWeights & operator=(const AliHBTLLWeights& /*source*/);
96 Int_t SetMomentaInLCMS(AliVAODParticle* part1, AliVAODParticle* part2);
97 void RandomPairDistances();
100 void Rotate(Double_t x, Double_t y, Double_t sphi, Double_t cphi, Double_t& xr, Double_t& yr);
101 void Boost (Double_t z, Double_t t, Double_t beta, Double_t gamma, Double_t& zt, Double_t& yt);
102 ClassDef(AliHBTLLWeights,2)