1 #ifndef ALIFASTGLAUBER_H
2 #define ALIFASTGLAUBER_H
3 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
8 // Utility class to make simple Glauber type calculations for collision geometries:
9 // Impact parameter, production points, reaction plane dependence
11 // Author: andreas.morsch@cern.ch
17 class AliFastGlauber : public TObject {
20 virtual ~AliFastGlauber(){;}
21 void SetWoodSaxonParameters(Double_t r0, Double_t d, Double_t w, Double_t n)
22 {fWSr0 = r0; fWSd = d; fWSw = w; fWSn = n;}
23 void SetMaxImpact(Float_t bmax = 20.) {fgBMax = bmax;};
24 void SetHardCrossSection(Float_t xs = 6.6) {fSigmaHard = xs;}
26 static Double_t WSb (Double_t *xx, Double_t *par);
27 static Double_t WSbz (Double_t *xx, Double_t *par);
28 static Double_t WSz (Double_t *xx, Double_t *par);
29 static Double_t WSta (Double_t *xx, Double_t *par);
30 static Double_t WStarfi (Double_t *xx, Double_t *par);
31 static Double_t WStaa (Double_t *xx, Double_t *par);
32 static Double_t WSgeo (Double_t *xx, Double_t *par);
33 static Double_t WSbinary (Double_t *xx, Double_t *par);
34 static Double_t WSN (Double_t *xx, Double_t *par);
35 static Double_t WAlmond (Double_t *xx, Double_t *par);
36 static Double_t WPathLength0 (Double_t *xx, Double_t *par);
37 static Double_t WPathLength (Double_t *xx, Double_t *par);
38 static Double_t WIntRadius (Double_t *xx, Double_t *par);
39 static Double_t WEnergyDensity (Double_t *xx, Double_t *par);
41 void Init(Int_t mode = 0);
48 void DrawKernel(Double_t b = 0.);
49 void DrawAlmond(Double_t b = 0.);
50 void DrawPathLength0(Double_t b = 0., Int_t iopt = 0);
51 void DrawPathLength(Double_t b, Int_t ni = 1000, Int_t iopt = 0);
52 void DrawIntRadius(Double_t b = 0.);
53 void DrawEnergyDensity();
55 Double_t CrossSection(Double_t b1, Double_t b2);
56 Double_t FractionOfHardCrossSection(Double_t b1, Double_t b2);
57 Double_t Binaries(Double_t b);
58 TF2* Kernel() {return fgWStarfi;}
59 TF1* Overlap() {return fgWStaa;}
60 void SimulateTrigger(Int_t n);
61 void GetRandom(Float_t& b, Float_t& p, Float_t& mult);
62 void GetRandom(Int_t& bin, Bool_t& hard);
63 Float_t GetRandomImpactParameter(Float_t bmin, Float_t bmax);
65 static TF1* fgWSb; // Wood-Saxon Function (b)
66 static TF2* fgWSbz; // Wood-Saxon Function (b, z)
67 static TF1* fgWSz; // Wood-Saxon Function (b = b0, z)
68 static TF1* fgWSta; // Thickness Function
69 static TF2* fgWStarfi; // Kernel for Overlap Function
70 static TF1* fgWStaa; // Overlap Function
71 static TF2* fgWAlmond; // Interaction Almond
72 static TF1* fgWPathLength0; // Path Length as a function of phi
73 static TF1* fgWPathLength; // Path Length as a function of phi
74 static TF1* fgWIntRadius; // Interaction Radius
75 static TF1* fgWSgeo; // dSigma/db geometric
76 static TF1* fgWSbinary; // dSigma/db binary
77 static TF1* fgWSN; // dN/db binary
78 static TF1* fgWEnergyDensity; // Energy density as a function of impact parameter
80 Float_t fWSr0; // Wood-Saxon Parameter r0
81 Float_t fWSd; // Wood-Saxon Parameter d
82 Float_t fWSw; // Wood-Saxon Parameter w
83 Float_t fWSn; // Wood-Saxon Parameter n
84 Float_t fSigmaHard; // Hard Cross Section
85 static Float_t fgBMax; // Maximum Impact Parameter
87 ClassDef(AliFastGlauber,1) // Event geometry simulation in the Glauber Model