| Geant4 Cross Reference |
>> 1 $Id: README,v 1.1 2008/11/03 11:48:35 gcosmo Exp $
1 --------------------------------------------- 2 ------------------------------------------------------------
2 3
3 Example of the external decayer implementatio << 4 Example of the external decayer implementation with Pythia6
4 --------------------------------------------- << 5 ===========================================================
5 6
6 The complete PYTHIA6 documentation can be fou << 7 The complete Pythia6 documentation can be found at:
7 http://home.thep.lu.se/~torbjorn/pythiaaux/re 8 http://home.thep.lu.se/~torbjorn/pythiaaux/recent.html
8 9
9 The PYTHIA6 external decayer was originally d << 10 The Pythia6 external decayer was originally developed within
10 the AliRoot framework, by Andreas Morsch (CER 11 the AliRoot framework, by Andreas Morsch (CERN).
11 The dependence on the ALICE software was take 12 The dependence on the ALICE software was taken off
12 by Christian Holm Christensen, 13 by Christian Holm Christensen,
13 The dependence on the Root framework and the 14 The dependence on the Root framework and the integration in
14 the Geant4 framework was done by Ivana Hrivna 15 the Geant4 framework was done by Ivana Hrivnacova (IPN Orsay).
15 16
16 --------------------------------------------- 17 ------------------------------------------------------------
17 18
18 The use of the external decayer is demonstrat << 19 The use of the external decayer is demonstrated on the modified
19 classes from common examples repository, see << 20 novice N03 example.
20 21
21 The G4Pythia6Decayer class provides the imple 22 The G4Pythia6Decayer class provides the implementation of the
22 G4VExternalDecayer interface with using PYTHI << 23 G4VExternalDecayer interface with using Pythia6. In order
23 to be able to use PYTHIA6, which is written i << 24 to be able to use Pythia6, which is written in FORTRAN,
24 a C++ interface class Pythia6 is provided. Th 25 a C++ interface class Pythia6 is provided. This class
25 interfaces only the PYTHIA6 functions relevan << 26 interfaces only the Pythia6 functions relevant to decay.
26 27
27 The G4Pythia6Decayer is instantiated in the P << 28 The G4Pythia6Decayer is instantiated in the ExN03PhysicsList class,
28 in the ConstructProcess() function where the << 29 in the ConstructDecay() function.
29 to G4Decay process for all particles. <<
30 To demonstrate the decay with external decaye 30 To demonstrate the decay with external decayer,
31 the B- meson is defined in ExG4PrimaryGenerat << 31 the B- meson is defined in ExN03PrimaryGeneratorAction,
32 as it has no own decay table defined within G 32 as it has no own decay table defined within Geant4.
33 33
34 With PYTHIA6, it is possible to force a selec << 34 With Pythia6, it is possible to force a selected decay
35 type. This selection can be chosen interactiv 35 type. This selection can be chosen interactively via
36 the implemented Geant4 UI command: 36 the implemented Geant4 UI command:
37 37
38 /pythia6Decayer/forceDecayType decayType 38 /pythia6Decayer/forceDecayType decayType
39 39
40 where the available decay types are listed i 40 where the available decay types are listed in the EDecayType
41 enumaration. 41 enumaration.
42 42
43 The classes Pythia6, G4Pythia6Decayer, G4Pyth 43 The classes Pythia6, G4Pythia6Decayer, G4Pythia6DecayerMessenger
44 are independent from the example classes and 44 are independent from the example classes and can be reused
45 in another user application. 45 in another user application.
46 46
47 Installation: 47 Installation:
48 48
49 1. Download the PYTHIA6 source file from the << 49 1. Download the Pythia6 source file from the Pythia6 download site:
50 http://www.hepforge.org/downloads/pythia6 50 http://www.hepforge.org/downloads/pythia6
51 51
52 2A.) With CMake: Build pythia6 library << 52 2. Define the environment variables:
53 << 53 PYTHIA6 the path to pythia-vesrinX.f source code
54 For a convenience a CMake file for buildin <<
55 the source is provided in <<
56 examples/extended/eventgenerator/CMakeList <<
57 Build the pythia6 library following the in <<
58 and then define the environment variables: <<
59 PYTHIA6 the path where pythia6 li <<
60 PYTHIA6_VERSION the pythia version <<
61 <<
62 2B.) With GNUmake: Define the environment var <<
63 PYTHIA6 the path to pythia-versi <<
64 PYTHIA6_VERSION the pythia version 54 PYTHIA6_VERSION the pythia version
65 55
66 e.g. If you download pythia-6.4.26.f.gz an << 56 e.g. If you download pythia-6.4.18.f.gz and unzip it in $HOME,
67 then you have to set: 57 then you have to set:
68 export PYTHIA6=$HOME 58 export PYTHIA6=$HOME
69 export PYTHIA6_VERSION="6.4.26" << 59 export PYTHIA6_VERSION="6.4.18"
70 60
71 Pythia6 will be then compiled together wit << 61 3. cd $G4INSTALL/example/extended/eventgenerator/pythia/decayer6
72 << 62 make
73 3. Compilation: << 63
74 Then the example is compiled in a standard << 64
75 Note that with GNUmake build, an additiona <<
76 needed before 'gmake'. <<
77 <<
78 Execution: 65 Execution:
79 66
80 % pythia6_decayer pythia6_decayer.in 67 % pythia6_decayer pythia6_decayer.in
81 68
82 This example uses the following user action cl <<
83 repository available in common subdirectory: <<
84 DetectorConstruction <<
85 GunPrimaryGeneratorAction <<