changes from Misha
[u/mrichter/AliRoot.git] / EVGEN / AliGenBox.cxx
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790bbabf 1/**************************************************************************
2 * Copyright(c) 1998-1999, 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
88cb7938 16/* $Id$ */
790bbabf 17
790bbabf 18
675e9664 19// Generator for particles in a preset
20// kinematic range (flat distribution)
21// Note that for a given theta pt and p are not independent
22// Range for only one variable (pt or p) should be given.
675e9664 23// Comments and suggestions: andreas.morsch@cern.ch
0af12c00 24
790bbabf 25
116cbefd 26#include "TPDGCode.h"
27
28#include "AliConst.h"
790bbabf 29#include "AliGenBox.h"
30#include "AliRun.h"
42cca6d4 31#include "AliGenEventHeader.h"
565cc9c0 32#include "TDatabasePDG.h"
33#include "AliPDG.h"
790bbabf 34
35ClassImp(AliGenBox)
36
37//_____________________________________________________________________________
38AliGenBox::AliGenBox()
1c56e311 39 :AliGenerator(),
a8c51211 40 fIpart(0),
41 fEtaMin(0),
42 fEtaMax(0)
790bbabf 43{
44 //
45 // Default constructor
46 //
790bbabf 47}
48
49//_____________________________________________________________________________
50AliGenBox::AliGenBox(Int_t npart)
1c56e311 51 :AliGenerator(npart),
a8c51211 52 fIpart(kProton),
53 fEtaMin(0),
54 fEtaMax(0)
790bbabf 55{
56 //
57 // Standard constructor
58 //
8b31bfac 59 fName = "Box";
60 fTitle = "Box particle generator";
790bbabf 61}
62
63//_____________________________________________________________________________
64
65void AliGenBox::Generate()
66{
67 //
68 // Generate one trigger
69 //
70
71 Float_t polar[3]= {0,0,0};
72 //
73 Float_t origin[3];
21391258 74 Float_t time;
790bbabf 75 Float_t p[3];
76 Int_t i, j, nt;
77 Double_t pmom, theta, phi, pt;
565cc9c0 78 Double_t y, mt;
790bbabf 79 //
80 Float_t random[6];
81 //
82 for (j=0;j<3;j++) origin[j]=fOrigin[j];
21391258 83 time = fTimeOrigin;
aee8290b 84 if(fVertexSmear==kPerEvent) {
c8f7f6f9 85 Vertex();
86 for (j=0;j<3;j++) origin[j]=fVertex[j];
21391258 87 time = fTime;
790bbabf 88 }
c8f7f6f9 89
565cc9c0 90 Double_t m = TDatabasePDG::Instance()->GetParticle(fIpart)->Mass();
91
790bbabf 92 for(i=0;i<fNpart;i++) {
65fb704d 93 Rndm(random,3);
898bb7f8 94
565cc9c0 95 if (TestBit(kYRange)) {
96 y = fYMin+random[0]*(fYMax-fYMin);
97
98 if(TestBit(kMomentumRange)) {
99 pmom=fPMin+random[1]*(fPMax-fPMin);
100 mt = TMath::Sqrt(pmom*pmom+m*m)/TMath::CosH(y);
101 pt = TMath::Sqrt(mt*mt - m*m);
102 } else {
103 pt=fPtMin+random[1]*(fPtMax-fPtMin);
104 mt=TMath::Sqrt(pt*pt+m*m);
105 }
106
107 phi=fPhiMin+random[2]*(fPhiMax-fPhiMin);
108 p[0] = pt*TMath::Cos(phi);
109 p[1] = pt*TMath::Sin(phi);
110 p[2] = mt*TMath::SinH(y);
790bbabf 111 } else {
565cc9c0 112 if (TestBit(kThetaRange)) {
113 theta = fThetaMin+random[0]*(fThetaMax-fThetaMin);
114 } else {
115 Float_t eta = fEtaMin+random[0]*(fEtaMax-fEtaMin);
116 theta = 2. * TMath::ATan(TMath::Exp(-eta));
117 }
118
119 if(TestBit(kMomentumRange)) {
120 pmom=fPMin+random[1]*(fPMax-fPMin);
121 pt=pmom*TMath::Sin(theta);
122 } else {
790bbabf 123
565cc9c0 124 pt=fPtMin+random[1]*(fPtMax-fPtMin);
125 pmom=pt/TMath::Sin(theta);
126 }
898bb7f8 127
565cc9c0 128 phi=fPhiMin+random[2]*(fPhiMax-fPhiMin);
129 p[0] = pt*TMath::Cos(phi);
130 p[1] = pt*TMath::Sin(phi);
131 p[2] = pmom*TMath::Cos(theta);
132 }
790bbabf 133
aee8290b 134 if(fVertexSmear==kPerTrack) {
65fb704d 135 Rndm(random,6);
790bbabf 136 for (j=0;j<3;j++) {
137 origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
138 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
139 }
21391258 140
141 Rndm(random,2);
142 time = fTimeOrigin + fOsigma[2]/TMath::Ccgs()*
143 TMath::Cos(2*random[0]*TMath::Pi())*
144 TMath::Sqrt(-2*TMath::Log(random[1]));
790bbabf 145 }
21391258 146 PushTrack(fTrackIt,-1,fIpart,p,origin,polar,time,kPPrimary,nt);
790bbabf 147 }
42cca6d4 148
149 AliGenEventHeader* header = new AliGenEventHeader("BOX");
150 header->SetPrimaryVertex(fVertex);
7cf36cae 151 header->SetNProduced(fNpart);
21391258 152 header->SetInteractionTime(fTime);
7cf36cae 153
154 // Passes header either to the container or to gAlice
155 if (fContainer) {
156 fContainer->AddHeader(header);
157 } else {
158 gAlice->SetGenEventHeader(header);
159 }
790bbabf 160}
161
162//_____________________________________________________________________________
163
164void AliGenBox::Init()
165{
166// Initialisation, check consistency of selected ranges
167 if(TestBit(kPtRange)&&TestBit(kMomentumRange))
168 Fatal("Init","You should not set the momentum range and the pt range!\n");
169 if((!TestBit(kPtRange))&&(!TestBit(kMomentumRange)))
170 Fatal("Init","You should set either the momentum or the pt range!\n");
565cc9c0 171 if((TestBit(kYRange)&&TestBit(kThetaRange)) || (TestBit(kYRange)&&TestBit(kEtaRange)) || (TestBit(kEtaRange)&&TestBit(kThetaRange)) )
172 Fatal("Init","You should only set the range of one of these variables: y, eta or theta\n");
173 if((!TestBit(kYRange)) && (!TestBit(kEtaRange)) && (!TestBit(kThetaRange)) )
174 Fatal("Init","You should set the range of one of these variables: y, eta or theta\n");
790bbabf 175}
176