c9c6bd3b |
1 | /************************************************************************** |
2 | * Copyright(c) 1998-2002, 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 | * Copyright(c) 1997, 1998, 2002, Adrian Alscher and Kai Hencken * |
17 | * See $ALICE_ROOT/EpEmGen/diffcross.f for full Copyright notice * |
18 | * * |
19 | * * |
20 | * Copyright(c) 2002 Kai Hencken, Yuri Kharlov, Serguei Sadovsky * |
21 | * See $ALICE_ROOT/EpEmGen/epemgen.f for full Copyright notice * |
22 | * * |
23 | **************************************************************************/ |
24 | //------------------------------------------------------------------------ |
25 | // TEpEmGen is an interface class to fortran event generator of |
26 | // single e+e- pair production in ultraperipheral PbPb collisions |
27 | // at 5.5 GeV/c |
28 | //% |
29 | // Yuri.Kharlov@cern.ch |
30 | // 9 October 2002 |
31 | //------------------------------------------------------------------------ |
32 | |
33 | #include "TEpEmGen.h" |
34 | #include "TClonesArray.h" |
35 | #include "TParticle.h" |
36 | #include "TEcommon.h" |
37 | |
38 | #ifndef WIN32 |
39 | # define ee_init ee_init_ |
40 | # define ee_event ee_event_ |
41 | #else |
42 | # define ee_init EE_INIT |
43 | # define ee_event EE_EVENT |
44 | #endif |
45 | |
46 | extern "C" { |
47 | void ee_init (Double_t &ymin, Double_t &ymax, Double_t &xmin, Double_t &xmax); |
48 | void ee_event (Double_t &ymin, Double_t &ymax, Double_t &xmin, Double_t &xmax, |
49 | Double_t &yE, Double_t &yP, Double_t &xE, Double_t &xP, |
50 | Double_t &phi, Double_t &w); |
51 | } |
52 | |
53 | ClassImp(TEpEmGen) |
54 | |
55 | //------------------------------------------------------------------------------ |
56 | TEpEmGen::TEpEmGen() : TGenerator("TEpEmGen","TEpEmGen") |
57 | { |
58 | // TEpEmGen constructor: creates a TClonesArray in which it will store all |
59 | // particles. Note that there may be only one functional TEpEmGen object |
60 | // at a time, so it's not use to create more than one instance of it. |
61 | |
62 | delete fParticles; // was allocated as TObjArray in TGenerator |
63 | fParticles = new TClonesArray("TParticle",2); |
64 | |
65 | } |
66 | |
67 | //------------------------------------------------------------------------------ |
68 | TEpEmGen::~TEpEmGen() |
69 | { |
70 | // Destroys the object, deletes and disposes all TParticles currently on list. |
71 | if (fParticles) { |
72 | fParticles->Delete(); |
73 | delete fParticles; |
74 | fParticles = 0; |
75 | } |
76 | } |
77 | |
78 | //______________________________________________________________________________ |
79 | void TEpEmGen::GenerateEvent(Double_t ymin, Double_t ymax, Double_t ptmin, Double_t ptmax, |
80 | Double_t &yElectron, Double_t &yPositron, |
81 | Double_t &xElectron, Double_t &xPositron, |
82 | Double_t &phi12, Double_t &weight) |
83 | { |
84 | //produce one event |
85 | ee_event(ymin,ymax,ptmin,ptmax, |
86 | yElectron,yPositron,xElectron,xPositron, |
87 | phi12,weight); |
88 | } |
89 | |
90 | //______________________________________________________________________________ |
91 | void TEpEmGen::Initialize(Double_t ymin, Double_t ymax, Double_t ptmin, Double_t ptmax) |
92 | { |
93 | // Initialize EpEmGen |
94 | Double_t ptminMeV = ptmin*1000; |
95 | Double_t ptmaxMeV = ptmax*1000; |
96 | ee_init(ymin,ymax,ptminMeV,ptmaxMeV); |
97 | } |
98 | |
99 | //______________________________________________________________________________ |
100 | Double_t TEpEmGen::GetXsection() |
101 | { |
102 | // Return cross section accumulated so far |
103 | return EEVENT.Xsecttot; |
104 | } |
105 | |
106 | //______________________________________________________________________________ |
107 | Double_t TEpEmGen::GetDsection() |
108 | { |
109 | // Return cross section error accumulated so far |
110 | return EEVENT.Dsecttot; |
111 | } |