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ccc5bf38 | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-2007, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | // Generator for particles according generic functions | |
17 | // | |
18 | // TF1 * fFMomentum; // momentum distribution function inGeV | |
19 | // TF1 * fFPhi; // phi distribution function in rad | |
20 | // TF1 * fFTheta; // theta distribution function in rad | |
21 | // TF3 * fFPosition; // position distribution function in cm | |
22 | // TF1 * fFPdg; // pdg distribution function | |
23 | // We assume that the moment, postion and PDG code of particles are independent | |
24 | // Only tracks/particle crossing the reference radius at given z range | |
25 | // | |
26 | // Origin: marian.ivanov@cern.ch | |
27 | ||
28 | ||
29 | /* | |
30 | Example generic function for cosmic generation: | |
31 | ||
32 | // | |
33 | AliGenFunction *generCosmic = new AliGenFunction; | |
34 | generCosmic->SetNumberParticles(100); | |
35 | TF1 *fmom = new TF1("fmom","TMath::Exp(-x/8)",0,30); | |
36 | // | |
37 | TF1 *fphi = new TF1("fphi","TMath::Gaus(x,-TMath::Pi()/2,0.3)",-3.14,3.14); | |
38 | TF1 *ftheta = new TF1("ftheta","TMath::Gaus(x,TMath::Pi()/2,0.3)",-3.14,3.14); | |
39 | TF3 *fpos = new TF3("fpos","1+(x+y+z)*0",-2000,2000,700,701,-2000,2000); | |
40 | TF1 * fpdg= new TF1("fpdg","1*(abs(x-13)<0.1)+1*(abs(x+13)<0.1)",-300,300); | |
41 | fpdg->SetNpx(10000); // neccessary - number of bins for generation | |
42 | generCosmic->SetVertexSmear(kPerEvent); | |
43 | generCosmic->SetFunctions(fmom,fphi,ftheta,fpos,fpdg); | |
44 | generCosmic->SetCylinder(375,-375,375); | |
45 | generCosmic->SetBkG(0.2); | |
46 | gener->AddGenerator(generCosmic,"generCosmic",1); | |
47 | ||
48 | ||
49 | ||
50 | */ | |
51 | ||
52 | ||
53 | ||
54 | ||
55 | #include <TParticle.h> | |
56 | #include <TF1.h> | |
57 | #include <TF3.h> | |
48c27d61 | 58 | #include <TDatabasePDG.h> |
ccc5bf38 | 59 | |
60 | #include "AliRun.h" | |
61 | #include "AliESDtrack.h" | |
62 | #include "AliESDVertex.h" | |
63 | #include "AliGenFunction.h" | |
64 | ||
65 | ClassImp(AliGenFunction) | |
66 | ||
67 | //----------------------------------------------------------------------------- | |
68 | AliGenFunction::AliGenFunction(): | |
69 | AliGenerator(), | |
70 | fBkG(0.), | |
71 | fFMomentum(0), // momentum distribution function | |
72 | fFPhi(0), // phi distribution function | |
73 | fFTheta(0), // theta distribution function | |
74 | fFPosition(0), // position distribution function | |
75 | fFPdg(0), // pdg distribution function | |
76 | fRefRadius(0), // reference radius to be crossed | |
77 | fZmin(0), // minimal z at reference radius | |
78 | fZmax(0), // z at reference radius | |
79 | fMaxTrial(10000) // maximal number of attempts | |
80 | { | |
81 | // | |
82 | // Default constructor | |
83 | // | |
84 | SetNumberParticles(1); | |
85 | } | |
86 | //----------------------------------------------------------------------------- | |
87 | void AliGenFunction::Generate() | |
88 | { | |
89 | // | |
90 | // Generate one muon | |
91 | // | |
92 | Int_t naccepted =0; | |
93 | ||
94 | for (Int_t ipart=0; ipart<fMaxTrial && naccepted<fNpart; ipart++){ | |
95 | // | |
96 | // | |
97 | // | |
98 | Float_t mom[3]; | |
99 | Float_t posf[3]; | |
100 | Double_t pos[3]; | |
101 | Int_t pdg; | |
102 | Double_t ptot,pt, phi, theta; | |
103 | // | |
104 | ptot = fFMomentum->GetRandom(); | |
105 | phi = fFPhi->GetRandom(); | |
106 | theta = fFTheta->GetRandom(); | |
107 | pt = ptot*TMath::Sin(theta); | |
108 | mom[0] = pt*TMath::Cos(phi); | |
109 | mom[1] = pt*TMath::Sin(phi); | |
110 | mom[2] = ptot*TMath::Cos(theta); | |
111 | ||
112 | // | |
113 | fFPosition->GetRandom3(pos[0],pos[1],pos[2]); | |
114 | posf[0]=pos[0]; | |
115 | posf[1]=pos[1]; | |
116 | posf[2]=pos[2]; | |
117 | pdg = TMath::Nint(fFPdg->GetRandom()); | |
118 | if (!IntersectCylinder(fRefRadius,fZmin, fZmax, pdg, posf, mom)) continue; | |
119 | // | |
120 | // | |
121 | Float_t polarization[3]= {0,0,0}; | |
122 | Int_t nt; | |
123 | PushTrack(fTrackIt,-1,pdg,mom, posf, polarization,0,kPPrimary,nt); | |
124 | naccepted++; | |
125 | } | |
126 | ||
127 | ||
128 | return; | |
129 | } | |
130 | //----------------------------------------------------------------------------- | |
131 | void AliGenFunction::Init() | |
132 | { | |
133 | // | |
134 | // Initialisation, check consistency of selected ranges | |
135 | // | |
136 | printf("************ AliGenFunction ****************\n"); | |
137 | printf("************************************************\n"); | |
138 | if (!fFMomentum){ | |
139 | AliFatal("Momentum distribution function not specified"); | |
140 | } | |
141 | if (!fFPosition){ | |
142 | AliFatal("Position distribution function not specified"); | |
143 | } | |
144 | if (!fFPdg){ | |
145 | AliFatal("PDG distribution function not specified"); | |
146 | } | |
147 | if (fZmin==fZmax){ | |
148 | AliFatal("Z range not specified"); | |
149 | } | |
150 | ||
151 | return; | |
152 | } | |
153 | ||
154 | void AliGenFunction::SetFunctions(TF1 * momentum, TF1 *fphi, TF1 *ftheta,TF3 * position, TF1* pdg){ | |
155 | // | |
156 | // | |
157 | // | |
158 | fFMomentum = momentum; | |
159 | fFPhi = fphi; | |
160 | fFTheta = ftheta; | |
161 | fFPosition = position; | |
162 | fFPdg = pdg; | |
163 | } | |
164 | ||
165 | void AliGenFunction::SetCylinder(Double_t refR, Double_t zmin, Double_t zmax){ | |
166 | // | |
167 | // | |
168 | // | |
169 | fRefRadius = refR; // reference radius to be crossed | |
170 | fZmin = zmin; // minimal z at reference radius | |
171 | fZmax = zmax; // maximal z at reference radius | |
172 | ||
173 | } | |
174 | ||
175 | ||
176 | //----------------------------------------------------------------------------- | |
177 | Bool_t AliGenFunction::IntersectCylinder(Float_t r,Float_t zmin, Float_t zmax,Int_t pdg, | |
178 | Float_t o[3],Float_t p[3]) const | |
179 | { | |
180 | // | |
181 | // Intersection between muon and cylinder [-z,+z] with radius r | |
182 | // | |
183 | Double_t mass=0; | |
184 | if (TDatabasePDG::Instance()->GetParticle(pdg)){ | |
185 | mass = TDatabasePDG::Instance()->GetParticle(13)->Mass(); | |
186 | } | |
187 | ||
188 | Float_t en = TMath::Sqrt(mass*mass+p[0]*p[0]+p[1]*p[1]+p[2]*p[2]); | |
189 | TParticle part(pdg,0,0,0,0,0,p[0],p[1],p[2],en,o[0],o[1],o[2],0); | |
190 | AliESDtrack track(&part); | |
191 | Double_t pos[3]={0.,0.,0.},sigma[3]={0.,0.,0.}; | |
192 | AliESDVertex origin(pos,sigma); | |
193 | ||
194 | track.RelateToVertex(&origin,fBkG,10000.); | |
195 | ||
196 | Float_t d0z0[2],covd0z0[3]; | |
197 | track.GetImpactParameters(d0z0,covd0z0); | |
198 | ||
199 | // check rphi | |
200 | if(TMath::Abs(d0z0[0])>r) return kFALSE; | |
201 | // check z | |
202 | if(d0z0[1]>zmax) return kFALSE; | |
203 | if(d0z0[1]<zmin) return kFALSE; | |
204 | // | |
205 | return kTRUE; | |
206 | } |