1 | // Pythia.h is a part of the PYTHIA event generator. |
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2 | // Copyright (C) 2012 Torbjorn Sjostrand. |
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3 | // PYTHIA is licenced under the GNU GPL version 2, see COPYING for details. |
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4 | // Please respect the MCnet Guidelines, see GUIDELINES for details. |
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5 | |
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6 | // This file contains the main class for event generation. |
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7 | // Pythia: provide the main user interface to everything else. |
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8 | |
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9 | #ifndef Pythia8_Pythia_H |
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10 | #define Pythia8_Pythia_H |
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11 | |
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12 | #include "Analysis.h" |
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13 | #include "Basics.h" |
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14 | #include "BeamParticle.h" |
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15 | #include "BeamShape.h" |
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16 | #include "Event.h" |
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17 | #include "FragmentationFlavZpT.h" |
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18 | #include "HadronLevel.h" |
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19 | #include "History.h" |
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20 | #include "Info.h" |
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21 | #include "LesHouches.h" |
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22 | #include "MergingHooks.h" |
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23 | #include "PartonLevel.h" |
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24 | #include "ParticleData.h" |
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25 | #include "PartonDistributions.h" |
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26 | #include "PartonSystems.h" |
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27 | #include "ProcessLevel.h" |
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28 | #include "PythiaStdlib.h" |
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29 | #include "ResonanceWidths.h" |
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30 | #include "RHadrons.h" |
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31 | #include "Settings.h" |
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32 | #include "SigmaTotal.h" |
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33 | #include "SpaceShower.h" |
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34 | #include "StandardModel.h" |
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35 | #include "SusyLesHouches.h" |
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36 | #include "TimeShower.h" |
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37 | #include "UserHooks.h" |
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38 | |
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39 | namespace Pythia8 { |
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40 | |
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41 | //========================================================================== |
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42 | |
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43 | // The Pythia class contains the top-level routines to generate an event. |
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44 | |
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45 | class Pythia { |
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46 | |
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47 | public: |
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48 | |
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49 | // Constructor. (See Pythia.cc file.) |
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50 | Pythia(string xmlDir = "../xmldoc"); |
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51 | |
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52 | // Destructor. (See Pythia.cc file.) |
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53 | ~Pythia(); |
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54 | |
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55 | // Read in one update for a setting or particle data from a single line. |
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56 | bool readString(string, bool warn = true); |
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57 | |
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58 | // Read in updates for settings or particle data from user-defined file. |
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59 | bool readFile(string fileName, bool warn = true, |
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60 | int subrun = SUBRUNDEFAULT); |
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61 | bool readFile(string fileName, int subrun) { |
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62 | return readFile(fileName, true, subrun);} |
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63 | bool readFile(istream& is = cin, bool warn = true, |
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64 | int subrun = SUBRUNDEFAULT); |
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65 | bool readFile(istream& is, int subrun) { |
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66 | return readFile(is, true, subrun);} |
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67 | |
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68 | // Possibility to pass in pointers to PDF's. |
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69 | bool setPDFPtr( PDF* pdfAPtrIn, PDF* pdfBPtrIn, PDF* pdfHardAPtrIn = 0, |
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70 | PDF* pdfHardBPtrIn = 0, PDF* pdfPomAPtrIn = 0, PDF* pdfPomBPtrIn = 0); |
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71 | |
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72 | // Possibility to pass in pointer to external LHA-interfaced generator. |
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73 | bool setLHAupPtr( LHAup* lhaUpPtrIn) {lhaUpPtr = lhaUpPtrIn; return true;} |
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74 | |
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75 | // Possibility to pass in pointer for external handling of some decays. |
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76 | bool setDecayPtr( DecayHandler* decayHandlePtrIn, |
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77 | vector<int> handledParticlesIn) {decayHandlePtr = decayHandlePtrIn; |
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78 | handledParticles.resize(0); |
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79 | for(int i = 0; i < int(handledParticlesIn.size()); ++i) |
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80 | handledParticles.push_back( handledParticlesIn[i] ); return true;} |
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81 | |
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82 | // Possibility to pass in pointer for external random number generation. |
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83 | bool setRndmEnginePtr( RndmEngine* rndmEnginePtrIn) |
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84 | { return rndm.rndmEnginePtr( rndmEnginePtrIn);} |
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85 | |
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86 | // Possibility to pass in pointer for user hooks. |
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87 | bool setUserHooksPtr( UserHooks* userHooksPtrIn) |
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88 | { userHooksPtr = userHooksPtrIn; return true;} |
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89 | |
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90 | // Possibility to pass in pointer for merging hooks. |
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91 | bool setMergingHooksPtr( MergingHooks* mergingHooksPtrIn) |
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92 | { mergingHooksPtr = mergingHooksPtrIn; return true;} |
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93 | |
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94 | // Possibility to pass in pointer for beam shape. |
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95 | bool setBeamShapePtr( BeamShape* beamShapePtrIn) |
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96 | { beamShapePtr = beamShapePtrIn; return true;} |
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97 | |
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98 | // Possibility to pass in pointer(s) for external cross section. |
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99 | bool setSigmaPtr( SigmaProcess* sigmaPtrIn) |
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100 | { sigmaPtrs.push_back( sigmaPtrIn); return true;} |
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101 | |
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102 | // Possibility to pass in pointer(s) for external resonance. |
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103 | bool setResonancePtr( ResonanceWidths* resonancePtrIn) |
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104 | { resonancePtrs.push_back( resonancePtrIn); return true;} |
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105 | |
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106 | // Possibility to pass in pointer for external showers. |
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107 | bool setShowerPtr( TimeShower* timesDecPtrIn, |
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108 | TimeShower* timesPtrIn = 0, SpaceShower* spacePtrIn = 0) |
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109 | { timesDecPtr = timesDecPtrIn; timesPtr = timesPtrIn; |
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110 | spacePtr = spacePtrIn; return true;} |
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111 | |
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112 | // Initialization using the Beams variables. |
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113 | bool init(); |
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114 | |
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115 | // Deprecated: initialization in the CM frame. |
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116 | bool init( int idAin, int idBin, double eCMin); |
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117 | |
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118 | // Deprecated: initialization with two collinear beams, e.g. fixed target. |
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119 | bool init( int idAin, int idBin, double eAin, double eBin); |
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120 | |
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121 | // Deprecated: initialization with two acollinear beams. |
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122 | bool init( int idAin, int idBin, double pxAin, double pyAin, |
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123 | double pzAin, double pxBin, double pyBin, double pzBin); |
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124 | |
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125 | // Deprecated: initialization by a Les Houches Event File. |
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126 | bool init( string LesHouchesEventFile, bool skipInit = false); |
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127 | |
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128 | // Deprecated: initialization according to the Les Houches Accord. |
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129 | bool init( LHAup* lhaUpPtrIn); |
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130 | |
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131 | // Generate the next event. |
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132 | bool next(); |
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133 | |
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134 | // Generate only a single timelike shower as in a decay. |
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135 | int forceTimeShower( int iBeg, int iEnd, double pTmax, int nBranchMax = 0) |
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136 | { return timesDecPtr->shower( iBeg, iEnd, event, pTmax, nBranchMax); } |
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137 | |
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138 | // Generate only the hadronization/decay stage. |
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139 | bool forceHadronLevel( bool findJunctions = true); |
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140 | |
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141 | // Special routine to allow more decays if on/off switches changed. |
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142 | bool moreDecays() {return hadronLevel.moreDecays(event);} |
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143 | |
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144 | // Special routine to force R-hadron decay when not done before. |
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145 | bool forceRHadronDecays() {return doRHadronDecays();} |
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146 | |
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147 | // List the current Les Houches event. |
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148 | void LHAeventList(ostream& os = cout) { |
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149 | if (lhaUpPtr != 0) lhaUpPtr->listEvent(os);} |
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150 | |
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151 | // Skip a number of Les Houches events at input. |
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152 | bool LHAeventSkip(int nSkip) { |
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153 | if (lhaUpPtr != 0) return lhaUpPtr->skipEvent(nSkip); return false;} |
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154 | |
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155 | // Main routine to provide final statistics on generation. |
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156 | void stat(); |
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157 | |
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158 | // Deprecated: alternative to provide final statistics on generation. |
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159 | void statistics(bool all = false, bool reset = false); |
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160 | |
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161 | // Read in settings values: shorthand, not new functionality. |
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162 | bool flag(string key) {return settings.flag(key);} |
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163 | int mode(string key) {return settings.mode(key);} |
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164 | double parm(string key) {return settings.parm(key);} |
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165 | string word(string key) {return settings.word(key);} |
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166 | |
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167 | // The event record for the parton-level central process. |
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168 | Event process; |
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169 | |
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170 | // The event record for the complete event history. |
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171 | Event event; |
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172 | |
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173 | // Information on the generation: current subprocess and error statistics. |
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174 | Info info; |
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175 | |
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176 | // Settings: databases of flags/modes/parms/words to control run. |
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177 | Settings settings; |
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178 | |
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179 | // ParticleData: the particle data table/database. |
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180 | ParticleData particleData; |
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181 | |
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182 | // Random number generator. |
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183 | Rndm rndm; |
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184 | |
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185 | // Standard Model couplings, including alphaS and alphaEM. |
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186 | Couplings couplings; |
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187 | CoupSUSY coupSUSY; |
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188 | Couplings* couplingsPtr; |
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189 | |
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190 | // SusyLesHouches - SLHA object for interface to SUSY spectra. |
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191 | SusyLesHouches slha; |
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192 | |
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193 | // The partonic content of each subcollision system (auxiliary to event). |
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194 | PartonSystems partonSystems; |
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195 | |
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196 | private: |
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197 | |
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198 | // Constants: could only be changed in the code itself. |
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199 | static const double VERSIONNUMBERCODE; |
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200 | static const int NTRY, SUBRUNDEFAULT; |
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201 | |
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202 | // Initialization data, extracted from database. |
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203 | string xmlPath; |
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204 | bool doProcessLevel, doPartonLevel, doHadronLevel, doDiffraction, |
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205 | doResDec, doFSRinRes, decayRHadrons, abortIfVeto, checkEvent, |
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206 | checkHistory; |
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207 | int nErrList; |
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208 | double epTolErr, epTolWarn; |
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209 | |
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210 | // Initialization data, extracted from init(...) call. |
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211 | bool isConstructed, isInit, isUnresolvedA, isUnresolvedB, showSaV, |
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212 | showMaD; |
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213 | int idA, idB, frameType, boostType, nCount, nShowLHA, nShowInfo, |
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214 | nShowProc, nShowEvt; |
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215 | double mA, mB, pxA, pxB, pyA, pyB, pzA, pzB, eA, eB, |
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216 | pzAcm, pzBcm, eCM, betaZ, gammaZ; |
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217 | Vec4 pAinit, pBinit, pAnow, pBnow; |
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218 | RotBstMatrix MfromCM, MtoCM; |
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219 | |
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220 | // information for error checkout. |
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221 | int nErrEvent; |
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222 | vector<int> iErrId, iErrCol, iErrNan, iErrNanVtx; |
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223 | |
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224 | // Pointers to the parton distributions of the two incoming beams. |
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225 | PDF* pdfAPtr; |
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226 | PDF* pdfBPtr; |
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227 | |
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228 | // Extra PDF pointers to be used in hard processes only. |
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229 | PDF* pdfHardAPtr; |
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230 | PDF* pdfHardBPtr; |
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231 | |
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232 | // Extra Pomeron PDF pointers to be used in diffractive processes only. |
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233 | PDF* pdfPomAPtr; |
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234 | PDF* pdfPomBPtr; |
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235 | |
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236 | // Keep track when "new" has been used and needs a "delete" for PDF's. |
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237 | bool useNewPdfA, useNewPdfB, useNewPdfHard, useNewPdfPomA, useNewPdfPomB; |
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238 | |
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239 | // The two incoming beams. |
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240 | BeamParticle beamA; |
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241 | BeamParticle beamB; |
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242 | |
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243 | // Alternative Pomeron beam-inside-beam. |
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244 | BeamParticle beamPomA; |
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245 | BeamParticle beamPomB; |
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246 | |
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247 | // LHAup object for generating external events. |
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248 | bool doLHA, useNewLHA; |
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249 | LHAup* lhaUpPtr; |
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250 | |
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251 | // Pointer to external decay handler and list of particles it handles. |
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252 | DecayHandler* decayHandlePtr; |
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253 | vector<int> handledParticles; |
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254 | |
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255 | // Pointer to UserHooks object for user interaction with program. |
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256 | UserHooks* userHooksPtr; |
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257 | bool hasUserHooks, doVetoProcess, doVetoPartons; |
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258 | |
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259 | // Pointer to BeamShape object for beam momentum and interaction vertex. |
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260 | BeamShape* beamShapePtr; |
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261 | bool useNewBeamShape, doMomentumSpread, doVertexSpread; |
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262 | |
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263 | // Pointers to external processes derived from the Pythia base classes. |
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264 | vector<SigmaProcess*> sigmaPtrs; |
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265 | |
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266 | // Pointers to external calculation of resonance widths. |
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267 | vector<ResonanceWidths*> resonancePtrs; |
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268 | |
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269 | // Pointers to timelike and spacelike showers. |
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270 | TimeShower* timesDecPtr; |
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271 | TimeShower* timesPtr; |
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272 | SpaceShower* spacePtr; |
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273 | bool useNewTimes, useNewSpace; |
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274 | |
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275 | // The main generator class to define the core process of the event. |
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276 | ProcessLevel processLevel; |
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277 | |
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278 | // The main generator class to produce the parton level of the event. |
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279 | PartonLevel partonLevel; |
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280 | |
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281 | // The main generator class to perform trial showers of the event. |
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282 | PartonLevel trialPartonLevel; |
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283 | |
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284 | // Pointer to MergingHooks object for user interaction with the merging. |
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285 | MergingHooks* mergingHooksPtr; |
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286 | bool hasMergingHooks, hasOwnMergingHooks, doUserMerging, |
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287 | doMGMerging, doKTMerging, doMerging, doPTLundMerging, |
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288 | doCutBasedMerging; |
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289 | // The main generator class to produce the hadron level of the event. |
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290 | HadronLevel hadronLevel; |
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291 | |
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292 | // The total cross section class is used both on process and parton level. |
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293 | SigmaTotal sigmaTot; |
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294 | |
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295 | // The RHadrons class is used both at PartonLevel and HadronLevel. |
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296 | RHadrons rHadrons; |
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297 | |
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298 | // Write the Pythia banner, with symbol and version information. |
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299 | void banner(ostream& os = cout); |
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300 | |
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301 | // Check for lines in file that mark the beginning of new subrun. |
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302 | int readSubrun(string line, bool warn = true, ostream& os = cout); |
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303 | |
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304 | // Check that combinations of settings are allowed; change if not. |
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305 | void checkSettings(); |
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306 | |
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307 | // Check that beams and beam combination can be handled. |
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308 | bool checkBeams(); |
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309 | |
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310 | // Calculate kinematics at initialization. |
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311 | bool initKinematics(); |
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312 | |
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313 | // Set up pointers to PDFs. |
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314 | bool initPDFs(); |
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315 | |
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316 | // Recalculate kinematics for each event when beam momentum has a spread. |
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317 | void nextKinematics(); |
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318 | |
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319 | // Boost from CM frame to lab frame, or inverse. Set production vertex. |
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320 | void boostAndVertex(bool toLab, bool setVertex); |
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321 | |
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322 | // Perform R-hadron decays. |
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323 | bool doRHadronDecays(); |
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324 | |
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325 | // Check that the final event makes sense. |
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326 | bool check(ostream& os = cout); |
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327 | |
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328 | // Auxiliary to set parton densities among list of possibilities. |
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329 | PDF* getPDFPtr(int idIn, int sequence = 1); |
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330 | |
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331 | // Initialization of SLHA data. |
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332 | bool initSLHA (); |
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333 | |
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334 | // Function to perform CKKW-L merging of the history. |
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335 | bool mergeProcess(); |
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336 | |
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337 | }; |
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338 | |
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339 | //========================================================================== |
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340 | |
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341 | } // end namespace Pythia8 |
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342 | |
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343 | #endif // Pythia8_Pythia_H |
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