1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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7 | // * conditions of the Geant4 Software License, included in the file * |
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8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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9 | // * include a list of copyright holders. * |
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10 | // * * |
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11 | // * Neither the authors of this software system, nor their employing * |
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12 | // * institutes,nor the agencies providing financial support for this * |
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13 | // * work make any representation or warranty, express or implied, * |
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14 | // * regarding this software system or assume any liability for its * |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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16 | // * for the full disclaimer and the limitation of liability. * |
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17 | // * * |
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18 | // * This code implementation is the result of the scientific and * |
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19 | // * technical work of the GEANT4 collaboration. * |
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20 | // * By using, copying, modifying or distributing the software (or * |
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21 | // * any work based on the software) you agree to acknowledge its * |
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22 | // * use in resulting scientific publications, and indicate your * |
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23 | // * acceptance of all terms of the Geant4 Software license. * |
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24 | // ******************************************************************** |
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25 | // |
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26 | // |
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27 | // $Id: G4HadronBuilder.cc,v 1.7 2008/04/25 14:20:14 vuzhinsk Exp $ |
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28 | // GEANT4 tag $Name: geant4-09-02 $ |
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29 | // |
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30 | // ----------------------------------------------------------------------------- |
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31 | // GEANT 4 class implementation file |
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32 | // |
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33 | // History: |
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34 | // Gunter Folger, August/September 2001 |
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35 | // Create class; algorithm previously in G4VLongitudinalStringDecay. |
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36 | // ----------------------------------------------------------------------------- |
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37 | |
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38 | #include "G4HadronBuilder.hh" |
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39 | #include "G4HadronicException.hh" |
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40 | #include "Randomize.hh" |
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41 | #include "G4ParticleTable.hh" |
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42 | |
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43 | G4HadronBuilder::G4HadronBuilder(G4double mesonMix, G4double barionMix, |
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44 | std::vector<double> scalarMesonMix, |
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45 | std::vector<double> vectorMesonMix) |
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46 | { |
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47 | mesonSpinMix=mesonMix; |
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48 | barionSpinMix=barionMix; |
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49 | scalarMesonMixings=scalarMesonMix; |
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50 | vectorMesonMixings=vectorMesonMix; |
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51 | } |
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52 | |
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53 | G4ParticleDefinition * G4HadronBuilder::Build(G4ParticleDefinition * black, G4ParticleDefinition * white) |
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54 | { |
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55 | |
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56 | if (black->GetParticleSubType()== "di_quark" || white->GetParticleSubType()== "di_quark" ) { |
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57 | |
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58 | // Barion |
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59 | Spin spin = (G4UniformRand() < barionSpinMix) ? SpinHalf : SpinThreeHalf; |
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60 | return Barion(black,white,spin); |
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61 | |
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62 | } else { |
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63 | |
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64 | // Meson |
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65 | Spin spin = (G4UniformRand() < mesonSpinMix) ? SpinZero : SpinOne; |
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66 | return Meson(black,white,spin); |
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67 | |
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68 | } |
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69 | } |
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70 | |
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71 | //------------------------------------------------------------------------- |
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72 | |
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73 | G4ParticleDefinition * G4HadronBuilder::BuildLowSpin(G4ParticleDefinition * black, G4ParticleDefinition * white) |
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74 | { |
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75 | if ( black->GetParticleSubType()== "quark" && white->GetParticleSubType()== "quark" ) { |
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76 | return Meson(black,white, SpinZero); |
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77 | } else { |
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78 | // will return a SpinThreeHalf Barion if all quarks the same |
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79 | return Barion(black,white, SpinHalf); |
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80 | } |
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81 | } |
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82 | |
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83 | //------------------------------------------------------------------------- |
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84 | |
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85 | G4ParticleDefinition * G4HadronBuilder::BuildHighSpin(G4ParticleDefinition * black, G4ParticleDefinition * white) |
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86 | { |
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87 | if ( black->GetParticleSubType()== "quark" && white->GetParticleSubType()== "quark" ) { |
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88 | return Meson(black,white, SpinOne); |
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89 | } else { |
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90 | return Barion(black,white,SpinThreeHalf); |
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91 | } |
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92 | } |
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93 | |
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94 | //------------------------------------------------------------------------- |
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95 | |
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96 | G4ParticleDefinition * G4HadronBuilder::Meson(G4ParticleDefinition * black, |
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97 | G4ParticleDefinition * white, Spin theSpin) |
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98 | { |
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99 | #ifdef G4VERBOSE |
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100 | // Verify Input Charge |
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101 | |
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102 | G4double charge = black->GetPDGCharge() |
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103 | + white->GetPDGCharge(); |
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104 | if (std::abs(charge) > 2 || std::abs(3.*charge - 3*G4int(charge*1.001)) > perCent ) // 1.001 to avoid int(.9999) -> 0 |
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105 | { |
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106 | G4cerr << " G4HadronBuilder::Build()" << G4endl; |
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107 | G4cerr << " Invalid total charge found for on input: " |
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108 | << charge<< G4endl; |
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109 | G4cerr << " PGDcode input quark1/quark2 : " << |
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110 | black->GetPDGEncoding() << " / "<< |
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111 | white->GetPDGEncoding() << G4endl; |
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112 | G4cerr << G4endl; |
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113 | } |
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114 | #endif |
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115 | |
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116 | G4int id1= black->GetPDGEncoding(); |
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117 | G4int id2= white->GetPDGEncoding(); |
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118 | // G4int ifl1= std::max(std::abs(id1), std::abs(id2)); |
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119 | if ( std::abs(id1) < std::abs(id2) ) |
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120 | { |
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121 | G4int xchg = id1; |
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122 | id1 = id2; |
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123 | id2 = xchg; |
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124 | } |
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125 | |
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126 | if (std::abs(id1) > 3 ) |
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127 | throw G4HadronicException(__FILE__, __LINE__, "G4HadronBuilder::Meson : Illegal Quark content as input"); |
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128 | |
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129 | G4int PDGEncoding=0; |
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130 | |
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131 | if (id1 + id2 == 0) { |
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132 | G4double rmix = G4UniformRand(); |
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133 | G4int imix = 2*std::abs(id1) - 1; |
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134 | if(theSpin == SpinZero) { |
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135 | PDGEncoding = 110*(1 + (G4int)(rmix + scalarMesonMixings[imix - 1]) |
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136 | + (G4int)(rmix + scalarMesonMixings[imix]) |
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137 | ) + theSpin; |
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138 | } else { |
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139 | PDGEncoding = 110*(1 + (G4int)(rmix + vectorMesonMixings[imix - 1]) |
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140 | + (G4int)(rmix + vectorMesonMixings[imix]) |
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141 | ) + theSpin; |
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142 | } |
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143 | } else { |
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144 | PDGEncoding = 100 * std::abs(id1) + 10 * std::abs(id2) + theSpin; |
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145 | G4bool IsUp = (std::abs(id1)&1) == 0; // quark 1 up type quark (u or c) |
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146 | G4bool IsAnti = id1 < 0; // quark 1 is antiquark? |
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147 | if( (IsUp && IsAnti ) || (!IsUp && !IsAnti ) ) |
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148 | PDGEncoding = - PDGEncoding; |
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149 | } |
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150 | |
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151 | |
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152 | G4ParticleDefinition * MesonDef= |
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153 | G4ParticleTable::GetParticleTable()->FindParticle(PDGEncoding); |
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154 | #ifdef G4VERBOSE |
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155 | if (MesonDef == 0 ) { |
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156 | G4cerr << " G4HadronBuilder - Warning: No particle for PDGcode= " |
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157 | << PDGEncoding << G4endl; |
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158 | } |
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159 | if ( ( black->GetPDGCharge() |
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160 | + white->GetPDGCharge() |
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161 | - MesonDef->GetPDGCharge() ) > perCent ) { |
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162 | G4cerr << " G4HadronBuilder - Warning: Incorrect Charge : " |
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163 | << " Quark1/2 = " |
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164 | << black->GetParticleName() << " / " |
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165 | << white->GetParticleName() |
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166 | << " resulting Hadron " << MesonDef->GetParticleName() |
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167 | << G4endl; |
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168 | } |
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169 | #endif |
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170 | |
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171 | return MesonDef; |
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172 | } |
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173 | |
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174 | |
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175 | G4ParticleDefinition * G4HadronBuilder::Barion(G4ParticleDefinition * black, |
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176 | G4ParticleDefinition * white,Spin theSpin) |
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177 | { |
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178 | |
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179 | #ifdef G4VERBOSE |
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180 | // Verify Input Charge |
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181 | G4double charge = black->GetPDGCharge() |
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182 | + white->GetPDGCharge(); |
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183 | if (std::abs(charge) > 2 || std::abs(3.*charge - 3*G4int(charge*1.001)) > perCent ) |
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184 | { |
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185 | G4cerr << " G4HadronBuilder::Build()" << G4endl; |
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186 | G4cerr << " Invalid total charge found for on input: " |
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187 | << charge<< G4endl; |
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188 | G4cerr << " PGDcode input quark1/quark2 : " << |
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189 | black->GetPDGEncoding() << " / "<< |
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190 | white->GetPDGEncoding() << G4endl; |
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191 | G4cerr << G4endl; |
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192 | } |
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193 | #endif |
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194 | G4int id1= black->GetPDGEncoding(); |
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195 | G4int id2= white->GetPDGEncoding(); |
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196 | if ( std::abs(id1) < std::abs(id2) ) |
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197 | { |
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198 | G4int xchg = id1; |
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199 | id1 = id2; |
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200 | id2 = xchg; |
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201 | } |
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202 | |
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203 | if (std::abs(id1) < 1000 || std::abs(id2) > 3 ) |
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204 | throw G4HadronicException(__FILE__, __LINE__, "G4HadronBuilder::Barion: Illegal quark content as input"); |
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205 | |
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206 | G4int ifl1= std::abs(id1)/1000; |
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207 | G4int ifl2 = (std::abs(id1) - ifl1 * 1000)/100; |
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208 | G4int diquarkSpin = std::abs(id1)%10; |
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209 | G4int ifl3 = id2; |
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210 | if (id1 < 0) |
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211 | { |
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212 | ifl1 = - ifl1; |
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213 | ifl2 = - ifl2; |
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214 | } |
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215 | //... Construct barion, distinguish Lambda and Sigma barions. |
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216 | G4int kfla = std::abs(ifl1); |
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217 | G4int kflb = std::abs(ifl2); |
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218 | G4int kflc = std::abs(ifl3); |
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219 | |
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220 | G4int kfld = std::max(kfla,kflb); |
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221 | kfld = std::max(kfld,kflc); |
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222 | G4int kflf = std::min(kfla,kflb); |
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223 | kflf = std::min(kflf,kflc); |
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224 | |
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225 | G4int kfle = kfla + kflb + kflc - kfld - kflf; |
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226 | |
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227 | //... barion with content uuu or ddd or sss has always spin = 3/2 |
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228 | theSpin = (kfla == kflb && kflb == kflc)? SpinThreeHalf : theSpin; |
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229 | |
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230 | G4int kfll = 0; |
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231 | if(theSpin == SpinHalf && kfld > kfle && kfle > kflf) { |
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232 | // Spin J=1/2 and all three quarks different |
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233 | // Two states exist: (uds -> lambda or sigma0) |
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234 | // - lambda: s(ud)0 s : 3122; ie. reverse the two lighter quarks |
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235 | // - sigma0: s(ud)1 s : 3212 |
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236 | if(diquarkSpin == 1 ) { |
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237 | if ( kfla == kfld) { // heaviest quark in diquark |
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238 | kfll = 1; |
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239 | } else { |
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240 | kfll = (G4int)(0.25 + G4UniformRand()); |
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241 | } |
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242 | } |
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243 | if(diquarkSpin == 3 && kfla != kfld) |
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244 | kfll = (G4int)(0.75 + G4UniformRand()); |
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245 | } |
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246 | |
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247 | G4int PDGEncoding; |
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248 | if (kfll == 1) |
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249 | PDGEncoding = 1000 * kfld + 100 * kflf + 10 * kfle + theSpin; |
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250 | else |
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251 | PDGEncoding = 1000 * kfld + 100 * kfle + 10 * kflf + theSpin; |
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252 | |
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253 | if (id1 < 0) |
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254 | PDGEncoding = -PDGEncoding; |
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255 | |
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256 | |
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257 | G4ParticleDefinition * BarionDef= |
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258 | G4ParticleTable::GetParticleTable()->FindParticle(PDGEncoding); |
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259 | #ifdef G4VERBOSE |
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260 | if (BarionDef == 0 ) { |
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261 | G4cerr << " G4HadronBuilder - Warning: No particle for PDGcode= " |
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262 | << PDGEncoding << G4endl; |
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263 | } |
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264 | if ( ( black->GetPDGCharge() |
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265 | + white->GetPDGCharge() |
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266 | - BarionDef->GetPDGCharge() ) > perCent ) { |
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267 | G4cerr << " G4HadronBuilder - Warning: Incorrect Charge : " |
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268 | << " DiQuark/Quark = " |
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269 | << black->GetParticleName() << " / " |
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270 | << white->GetParticleName() |
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271 | << " resulting Hadron " << BarionDef->GetParticleName() |
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272 | << G4endl; |
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273 | } |
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274 | #endif |
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275 | |
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276 | return BarionDef; |
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277 | } |
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