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4bda3bc1 | 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 | /* $Id$ */ |
4bda3bc1 | 17 | |
508eeb68 | 18 | // |
19 | // Generator to simulate beam gas interactions. | |
20 | // At present single interactions are read from an external file. | |
21 | // Several interactions are combined in one event. | |
0af12c00 | 22 | // By default the vertex is smeared between +/- 20 m |
23 | // Author: andreas.morsch@cern.ch | |
4bda3bc1 | 24 | |
25 | #include "AliGenBeamGas.h" | |
4bda3bc1 | 26 | |
27 | #include <TParticle.h> | |
4bda3bc1 | 28 | |
29 | ||
198bb1c7 | 30 | ClassImp(AliGenBeamGas) |
4bda3bc1 | 31 | |
32 | AliGenBeamGas::AliGenBeamGas() | |
1c56e311 | 33 | :AliGenExtFile(), |
34 | fInteractions(1) | |
4bda3bc1 | 35 | { |
36 | // Constructor | |
37 | // | |
508eeb68 | 38 | fOsigma[0] = 0.; |
39 | fOsigma[1] = 0.; | |
40 | fOsigma[2] = 2000.; | |
4bda3bc1 | 41 | } |
42 | ||
198bb1c7 | 43 | AliGenBeamGas::AliGenBeamGas(const AliGenBeamGas & beamgas): |
1c56e311 | 44 | AliGenExtFile(beamgas), |
45 | fInteractions(1) | |
4bda3bc1 | 46 | { |
198bb1c7 | 47 | // Copy constructor |
48 | beamgas.Copy(*this); | |
4bda3bc1 | 49 | } |
50 | //____________________________________________________________ | |
51 | ||
52 | AliGenBeamGas::~AliGenBeamGas() | |
53 | { | |
54 | // Destructor | |
55 | delete fReader; | |
56 | } | |
57 | ||
58 | //___________________________________________________________ | |
59 | void AliGenBeamGas::Init() | |
60 | { | |
61 | // Initialize | |
62 | AliGenExtFile::Init(); | |
63 | } | |
64 | ||
65 | ||
66 | void AliGenBeamGas::Generate() | |
67 | { | |
68 | // Generate particles | |
69 | ||
70 | Float_t polar[3] = {0,0,0}; | |
71 | Float_t origin[3] = {0,0,0}; | |
72 | Float_t p[3]; | |
73 | Float_t random[2]; | |
74 | Int_t i, nt; | |
75 | Int_t nInt = 0; | |
76 | ||
77 | while(nInt < fInteractions) { | |
78 | // | |
79 | Rndm(random,2); | |
80 | // | |
81 | // Interaction vertex | |
82 | // | |
508eeb68 | 83 | origin[2] = 2. * fOsigma[2] * random[0] - fOsigma[2]; |
4bda3bc1 | 84 | // |
85 | // beam 1 or 2 | |
86 | // | |
87 | Float_t ibeam = (random[1] < 0.5) ? -1. : 1.; | |
88 | ||
89 | // | |
90 | // Read next event | |
91 | // | |
92 | Int_t nTracks = fReader->NextEvent(); | |
93 | if (nTracks == 0) { | |
94 | // printf("\n No more events !!! !\n"); | |
95 | Warning("AliGenBeamGas::Generate", | |
96 | "\nNo more events in external file!!!\n Last event may be empty or incomplete.\n"); | |
97 | return; | |
98 | } | |
99 | ||
100 | // | |
101 | // Stack filling loop | |
102 | // | |
103 | for (i = 0; i < nTracks; i++) { | |
104 | TParticle* iparticle = fReader->NextParticle(); | |
105 | p[0] = iparticle->Px(); | |
106 | p[1] = iparticle->Py(); | |
107 | p[2] = iparticle->Pz() * ibeam; | |
108 | ||
109 | Int_t idpart = iparticle->GetPdgCode(); | |
110 | Int_t decayed = iparticle->GetFirstDaughter(); | |
111 | Int_t doTracking = fTrackIt && (decayed < 0) && (TMath::Abs(idpart) > 10); | |
642f15cf | 112 | PushTrack(doTracking,-1,idpart,p,origin,polar,0,kPPrimary,nt); |
4bda3bc1 | 113 | KeepTrack(nt); |
114 | } // track loop | |
115 | nInt++; | |
116 | } // event loop | |
117 | // | |
118 | SetHighWaterMark(nt); | |
119 | // | |
120 | CdEventFile(); | |
121 | } | |
122 | ||
123 | ||
4bda3bc1 | 124 | |
dc1d768c | 125 | void AliGenBeamGas::Copy(TObject&) const |
198bb1c7 | 126 | { |
127 | // | |
128 | // Copy | |
129 | // | |
130 | Fatal("Copy","Not implemented!\n"); | |
131 | } | |
4bda3bc1 | 132 | |
133 | ||
134 | ||
135 | ||
136 | ||
137 |