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 | // 24.11.08 V. Grichine - first implementation |
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27 | // |
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28 | |
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29 | #include "G4GGNuclNuclCrossSection.hh" |
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30 | |
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31 | #include "G4ParticleTable.hh" |
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32 | #include "G4IonTable.hh" |
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33 | #include "G4ParticleDefinition.hh" |
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34 | #include "G4HadTmpUtil.hh" |
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35 | |
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36 | |
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37 | G4GGNuclNuclCrossSection::G4GGNuclNuclCrossSection() |
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38 | : fUpperLimit( 100000 * GeV ), |
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39 | fLowerLimit( 0.1 * MeV ), |
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40 | fRadiusConst( 1.08*fermi ), // 1.1, 1.3 ? |
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41 | fTotalXsc(0.0), fElasticXsc(0.0), fInelasticXsc(0.0), fProductionXsc(0.0), |
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42 | fDiffractionXsc(0.0), fHadronNucleonXsc(0.0) |
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43 | { |
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44 | theProton = G4Proton::Proton(); |
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45 | theNeutron = G4Neutron::Neutron(); |
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46 | } |
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47 | |
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48 | |
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49 | G4GGNuclNuclCrossSection::~G4GGNuclNuclCrossSection() |
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50 | {} |
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51 | |
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52 | |
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53 | G4bool |
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54 | G4GGNuclNuclCrossSection::IsApplicable(const G4DynamicParticle* aDP, |
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55 | const G4Element* anElement) |
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56 | { |
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57 | G4int Z = G4lrint(anElement->GetZ()); |
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58 | G4int N = G4lrint(anElement->GetN()); |
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59 | return IsIsoApplicable(aDP, Z, N); |
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60 | } |
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61 | |
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62 | /////////////////////////////////////////////////////////////////////////////// |
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63 | // |
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64 | // |
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65 | |
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66 | G4bool |
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67 | G4GGNuclNuclCrossSection::IsIsoApplicable(const G4DynamicParticle* aDP, |
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68 | G4int Z, G4int) |
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69 | { |
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70 | G4bool applicable = false; |
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71 | G4double kineticEnergy = aDP->GetKineticEnergy(); |
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72 | |
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73 | if (kineticEnergy >= fLowerLimit && Z > 1) applicable = true; |
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74 | return applicable; |
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75 | } |
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76 | |
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77 | /////////////////////////////////////////////////////////////////////////////// |
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78 | // |
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79 | // Calculates total and inelastic Xsc, derives elastic as total - inelastic |
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80 | // accordong to Glauber model with Gribov correction calculated in the dipole |
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81 | // approximation on light cone. Gaussian density helps to calculate rest |
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82 | // integrals of the model. [1] B.Z. Kopeliovich, nucl-th/0306044 |
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83 | |
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84 | |
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85 | G4double G4GGNuclNuclCrossSection:: |
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86 | GetCrossSection(const G4DynamicParticle* aParticle, const G4Element* anElement, |
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87 | G4double T) |
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88 | { |
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89 | G4int Z = G4lrint(anElement->GetZ()); |
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90 | G4int N = G4lrint(anElement->GetN()); |
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91 | return GetZandACrossSection(aParticle, Z, N, T); |
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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 | // Calculates total and inelastic Xsc, derives elastic as total - inelastic |
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97 | // accordong to Glauber model with Gribov correction calculated in the dipole |
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98 | // approximation on light cone. Gaussian density of point-like nucleons helps |
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99 | // to calculate rest integrals of the model. [1] B.Z. Kopeliovich, |
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100 | // nucl-th/0306044 + simplification above |
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101 | |
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102 | |
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103 | G4double G4GGNuclNuclCrossSection:: |
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104 | GetZandACrossSection(const G4DynamicParticle* aParticle, |
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105 | G4int tZ, G4int tA, G4double) |
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106 | { |
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107 | G4double xsection; |
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108 | G4double sigma; |
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109 | G4double cofInelastic = 2.4; |
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110 | G4double cofTotal = 2.0; |
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111 | G4double nucleusSquare; |
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112 | G4double cB; |
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113 | G4double ratio; |
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114 | |
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115 | G4double pZ = aParticle->GetDefinition()->GetPDGCharge(); |
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116 | G4double pA = aParticle->GetDefinition()->GetBaryonNumber(); |
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117 | |
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118 | G4double pTkin = aParticle->GetKineticEnergy(); |
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119 | pTkin /= pA; |
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120 | |
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121 | G4double pN = pA - pZ; |
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122 | if( pN < 0. ) pN = 0.; |
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123 | |
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124 | G4double tN = tA - tZ; |
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125 | if( tN < 0. ) tN = 0.; |
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126 | |
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127 | G4double tR = GetNucleusRadius(tA); |
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128 | G4double pR = GetNucleusRadius(pA); |
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129 | |
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130 | cB = GetCoulombBarier(aParticle, G4double(tZ), G4double(tA), pR, tR); |
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131 | if (cB > 0.) { |
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132 | |
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133 | sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) + |
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134 | (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron); |
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135 | |
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136 | nucleusSquare = cofTotal*pi*( pR*pR + tR*tR ); // basically 2piRR |
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137 | |
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138 | ratio = sigma/nucleusSquare; |
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139 | xsection = nucleusSquare*std::log( 1. + ratio ); |
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140 | fTotalXsc = xsection; |
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141 | fTotalXsc *= cB; |
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142 | |
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143 | fInelasticXsc = nucleusSquare*std::log( 1. + cofInelastic*ratio )/cofInelastic; |
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144 | |
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145 | fInelasticXsc *= cB; |
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146 | fElasticXsc = fTotalXsc - fInelasticXsc; |
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147 | |
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148 | // if (fElasticXsc < DBL_MIN) fElasticXsc = DBL_MIN; |
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149 | /* |
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150 | G4double difratio = ratio/(1.+ratio); |
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151 | |
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152 | fDiffractionXsc = 0.5*nucleusSquare*( difratio - std::log( 1. + difratio ) ); |
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153 | */ |
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154 | // production to be checked !!! edit MK xsc |
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155 | |
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156 | //sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscMK(theProton, pTkin, theProton) + |
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157 | // (pZ*tN+pN*tZ)*GetHadronNucleonXscMK(theProton, pTkin, theNeutron); |
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158 | |
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159 | sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) + |
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160 | (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron); |
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161 | |
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162 | ratio = sigma/nucleusSquare; |
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163 | fProductionXsc = nucleusSquare*std::log( 1. + cofInelastic*ratio )/cofInelastic; |
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164 | |
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165 | if (fElasticXsc < 0.) fElasticXsc = 0.; |
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166 | } |
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167 | else |
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168 | { |
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169 | fInelasticXsc = 0.; |
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170 | fTotalXsc = 0.; |
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171 | fElasticXsc = 0.; |
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172 | fProductionXsc = 0.; |
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173 | } |
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174 | return fInelasticXsc; // xsection; |
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175 | } |
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176 | |
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177 | /////////////////////////////////////////////////////////////////////////////// |
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178 | // |
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179 | // |
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180 | |
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181 | G4double G4GGNuclNuclCrossSection:: |
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182 | GetCoulombBarier(const G4DynamicParticle* aParticle, G4double tZ, G4double tA, |
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183 | G4double pR, G4double tR) |
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184 | { |
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185 | G4double ratio; |
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186 | G4double pZ = aParticle->GetDefinition()->GetPDGCharge(); |
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187 | |
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188 | G4double pTkin = aParticle->GetKineticEnergy(); |
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189 | // G4double pPlab = aParticle->GetTotalMomentum(); |
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190 | G4double pM = aParticle->GetDefinition()->GetPDGMass(); |
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191 | // G4double tM = tZ*proton_mass_c2 + (tA-tZ)*neutron_mass_c2; // ~ 1% accuracy |
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192 | G4double tM = G4ParticleTable::GetParticleTable()->GetIonTable()->GetIonMass( G4int(tZ), G4int(tA) ); |
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193 | G4double pElab = pTkin + pM; |
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194 | G4double totEcm = std::sqrt(pM*pM + tM*tM + 2.*pElab*tM); |
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195 | // G4double pPcm = pPlab*tM/totEcm; |
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196 | // G4double pTcm = std::sqrt(pM*pM + pPcm*pPcm) - pM; |
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197 | G4double totTcm = totEcm - pM -tM; |
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198 | |
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199 | G4double bC = fine_structure_const*hbarc*pZ*tZ; |
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200 | bC /= pR + tR; |
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201 | bC /= 2.; // 4., 2. parametrisation cof ??? vmg |
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202 | |
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203 | // G4cout<<"pTkin = "<<pTkin/GeV<<"; pPlab = " |
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204 | // <<pPlab/GeV<<"; bC = "<<bC/GeV<<"; pTcm = "<<pTcm/GeV<<G4endl; |
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205 | |
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206 | if( totTcm <= bC ) ratio = 0.; |
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207 | else ratio = 1. - bC/totTcm; |
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208 | |
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209 | // if(ratio < DBL_MIN) ratio = DBL_MIN; |
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210 | if( ratio < 0.) ratio = 0.; |
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211 | |
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212 | // G4cout <<"ratio = "<<ratio<<G4endl; |
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213 | return ratio; |
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214 | } |
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215 | |
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216 | |
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217 | ////////////////////////////////////////////////////////////////////////// |
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218 | // |
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219 | // Return single-diffraction/inelastic cross-section ratio |
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220 | |
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221 | G4double G4GGNuclNuclCrossSection:: |
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222 | GetRatioSD(const G4DynamicParticle* aParticle, G4double tA, G4double tZ) |
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223 | { |
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224 | G4double sigma, cofInelastic = 2.4, cofTotal = 2.0, nucleusSquare, ratio; |
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225 | |
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226 | G4double pZ = aParticle->GetDefinition()->GetPDGCharge(); |
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227 | G4double pA = aParticle->GetDefinition()->GetBaryonNumber(); |
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228 | |
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229 | G4double pTkin = aParticle->GetKineticEnergy(); |
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230 | pTkin /= pA; |
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231 | |
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232 | G4double pN = pA - pZ; |
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233 | if( pN < 0. ) pN = 0.; |
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234 | |
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235 | G4double tN = tA - tZ; |
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236 | if( tN < 0. ) tN = 0.; |
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237 | |
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238 | G4double tR = GetNucleusRadius(tA); |
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239 | G4double pR = GetNucleusRadius(pA); |
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240 | |
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241 | sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) + |
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242 | (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron); |
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243 | |
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244 | nucleusSquare = cofTotal*pi*( pR*pR + tR*tR ); // basically 2piRR |
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245 | ratio = sigma/nucleusSquare; |
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246 | fInelasticXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic; |
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247 | G4double difratio = ratio/(1.+ratio); |
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248 | |
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249 | fDiffractionXsc = 0.5*nucleusSquare*( difratio - std::log( 1. + difratio ) ); |
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250 | |
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251 | if (fInelasticXsc > 0.) ratio = fDiffractionXsc/fInelasticXsc; |
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252 | else ratio = 0.; |
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253 | |
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254 | return ratio; |
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255 | } |
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256 | |
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257 | ////////////////////////////////////////////////////////////////////////// |
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258 | // |
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259 | // Return quasi-elastic/inelastic cross-section ratio |
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260 | |
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261 | G4double G4GGNuclNuclCrossSection:: |
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262 | GetRatioQE(const G4DynamicParticle* aParticle, G4double tA, G4double tZ) |
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263 | { |
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264 | G4double sigma, cofInelastic = 2.4, cofTotal = 2.0, nucleusSquare, ratio; |
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265 | |
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266 | G4double pZ = aParticle->GetDefinition()->GetPDGCharge(); |
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267 | G4double pA = aParticle->GetDefinition()->GetBaryonNumber(); |
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268 | |
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269 | G4double pTkin = aParticle->GetKineticEnergy(); |
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270 | pTkin /= pA; |
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271 | |
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272 | G4double pN = pA - pZ; |
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273 | if( pN < 0. ) pN = 0.; |
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274 | |
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275 | G4double tN = tA - tZ; |
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276 | if( tN < 0. ) tN = 0.; |
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277 | |
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278 | G4double tR = GetNucleusRadius(tA); |
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279 | G4double pR = GetNucleusRadius(pA); |
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280 | |
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281 | sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) + |
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282 | (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron); |
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283 | |
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284 | nucleusSquare = cofTotal*pi*( pR*pR + tR*tR ); // basically 2piRR |
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285 | ratio = sigma/nucleusSquare; |
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286 | fInelasticXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic; |
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287 | |
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288 | // sigma = GetHNinelasticXsc(aParticle, tA, tZ); |
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289 | ratio = sigma/nucleusSquare; |
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290 | fProductionXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic; |
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291 | |
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292 | if (fInelasticXsc > fProductionXsc) ratio = (fInelasticXsc-fProductionXsc)/fInelasticXsc; |
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293 | else ratio = 0.; |
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294 | if ( ratio < 0. ) ratio = 0.; |
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295 | |
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296 | return ratio; |
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297 | } |
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298 | |
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299 | /////////////////////////////////////////////////////////////////////////////// |
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300 | // |
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301 | // Returns hadron-nucleon Xsc according to differnt parametrisations: |
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302 | // [2] E. Levin, hep-ph/9710546 |
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303 | // [3] U. Dersch, et al, hep-ex/9910052 |
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304 | // [4] M.J. Longo, et al, Phys.Rev.Lett. 33 (1974) 725 |
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305 | |
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306 | G4double |
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307 | G4GGNuclNuclCrossSection::GetHadronNucleonXsc(const G4DynamicParticle* aParticle, |
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308 | const G4Element* anElement) |
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309 | { |
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310 | G4int At = G4lrint(anElement->GetN()); // number of nucleons |
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311 | G4int Zt = G4lrint(anElement->GetZ()); // number of protons |
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312 | return GetHadronNucleonXsc(aParticle, At, Zt); |
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313 | } |
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314 | |
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315 | |
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316 | |
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317 | |
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318 | /////////////////////////////////////////////////////////////////////////////// |
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319 | // |
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320 | // Returns hadron-nucleon Xsc according to differnt parametrisations: |
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321 | // [2] E. Levin, hep-ph/9710546 |
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322 | // [3] U. Dersch, et al, hep-ex/9910052 |
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323 | // [4] M.J. Longo, et al, Phys.Rev.Lett. 33 (1974) 725 |
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324 | |
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325 | G4double |
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326 | G4GGNuclNuclCrossSection::GetHadronNucleonXsc(const G4DynamicParticle* aParticle, |
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327 | G4int At, G4int Zt) |
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328 | { |
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329 | G4double xsection = 0.; |
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330 | |
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331 | G4double targ_mass = G4ParticleTable::GetParticleTable()-> |
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332 | GetIonTable()->GetIonMass(Zt, At); |
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333 | targ_mass = 0.939*GeV; // ~mean neutron and proton ??? |
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334 | |
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335 | G4double proj_mass = aParticle->GetMass(); |
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336 | G4double proj_momentum = aParticle->GetMomentum().mag(); |
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337 | G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum ); |
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338 | |
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339 | sMand /= GeV*GeV; // in GeV for parametrisation |
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340 | proj_momentum /= GeV; |
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341 | const G4ParticleDefinition* pParticle = aParticle->GetDefinition(); |
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342 | |
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343 | if(pParticle == theNeutron) // as proton ??? |
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344 | { |
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345 | xsection = G4double(At)*(21.70*std::pow(sMand,0.0808) + 56.08*std::pow(sMand,-0.4525)); |
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346 | } |
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347 | else if(pParticle == theProton) |
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348 | { |
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349 | xsection = G4double(At)*(21.70*std::pow(sMand,0.0808) + 56.08*std::pow(sMand,-0.4525)); |
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350 | } |
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351 | |
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352 | xsection *= millibarn; |
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353 | return xsection; |
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354 | } |
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355 | |
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356 | |
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357 | /////////////////////////////////////////////////////////////////////////////// |
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358 | // |
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359 | // Returns hadron-nucleon Xsc according to PDG parametrisation (2005): |
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360 | // http://pdg.lbl.gov/2006/reviews/hadronicrpp.pdf |
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361 | |
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362 | G4double |
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363 | G4GGNuclNuclCrossSection::GetHadronNucleonXscPDG(const G4DynamicParticle* aParticle, |
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364 | const G4Element* anElement) |
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365 | { |
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366 | G4int At = G4lrint(anElement->GetN()); // number of nucleons |
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367 | G4int Zt = G4lrint(anElement->GetZ()); // number of protons |
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368 | return GetHadronNucleonXscPDG( aParticle, At, Zt ); |
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369 | } |
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370 | |
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371 | |
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372 | /////////////////////////////////////////////////////////////////////////////// |
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373 | // |
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374 | // Returns hadron-nucleon Xsc according to PDG parametrisation (2005): |
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375 | // http://pdg.lbl.gov/2006/reviews/hadronicrpp.pdf |
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376 | // At = number of nucleons, Zt = number of protons |
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377 | |
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378 | G4double |
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379 | G4GGNuclNuclCrossSection::GetHadronNucleonXscPDG(const G4DynamicParticle* aParticle, |
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380 | G4int At, G4int Zt) |
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381 | { |
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382 | G4double xsection = 0.; |
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383 | |
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384 | G4double Nt = At-Zt; // number of neutrons |
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385 | if (Nt < 0.) Nt = 0.; |
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386 | |
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387 | G4double targ_mass = G4ParticleTable::GetParticleTable()-> |
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388 | GetIonTable()->GetIonMass(Zt, At); |
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389 | targ_mass = 0.939*GeV; // ~mean neutron and proton ??? |
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390 | |
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391 | G4double proj_mass = aParticle->GetMass(); |
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392 | G4double proj_momentum = aParticle->GetMomentum().mag(); |
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393 | G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum ); |
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394 | sMand /= GeV*GeV; // in GeV for parametrisation |
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395 | |
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396 | // General PDG fit constants |
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397 | |
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398 | G4double s0 = 5.38*5.38; // in Gev^2 |
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399 | G4double eta1 = 0.458; |
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400 | G4double eta2 = 0.458; |
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401 | G4double B = 0.308; |
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402 | |
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403 | const G4ParticleDefinition* pParticle = aParticle->GetDefinition(); |
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404 | |
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405 | if(pParticle == theNeutron) // proton-neutron fit |
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406 | { |
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407 | xsection = G4double(Zt)*( 35.80 + B*std::pow(std::log(sMand/s0),2.) |
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408 | + 40.15*std::pow(sMand,-eta1) - 30.*std::pow(sMand,-eta2)); |
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409 | xsection += Nt*(35.45 + B*std::pow(std::log(sMand/s0),2.) |
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410 | + 42.53*std::pow(sMand,-eta1) - 33.34*std::pow(sMand,-eta2)); // pp for nn |
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411 | } |
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412 | else if(pParticle == theProton) |
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413 | { |
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414 | xsection = G4double(Zt)*(35.45 + B*std::pow(std::log(sMand/s0),2.) |
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415 | + 42.53*std::pow(sMand,-eta1) - 33.34*std::pow(sMand,-eta2)); |
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416 | |
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417 | xsection += Nt*(35.80 + B*std::pow(std::log(sMand/s0),2.) |
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418 | + 40.15*std::pow(sMand,-eta1) - 30.*std::pow(sMand,-eta2)); |
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419 | } |
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420 | xsection *= millibarn; // parametrised in mb |
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421 | return xsection; |
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422 | } |
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423 | |
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424 | |
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425 | /////////////////////////////////////////////////////////////////////////////// |
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426 | // |
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427 | // Returns nucleon-nucleon cross-section based on N. Starkov parametrisation of |
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428 | // data from mainly http://wwwppds.ihep.su:8001/c5-6A.html database |
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429 | // projectile nucleon is pParticle with pTkin shooting target nucleon tParticle |
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430 | |
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431 | G4double |
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432 | G4GGNuclNuclCrossSection::GetHadronNucleonXscNS(G4ParticleDefinition* pParticle, |
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433 | G4double pTkin, |
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434 | G4ParticleDefinition* tParticle) |
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435 | { |
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436 | G4double xsection(0), Delta, A0, B0; |
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437 | G4double hpXsc(0); |
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438 | G4double hnXsc(0); |
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439 | |
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440 | G4double targ_mass = tParticle->GetPDGMass(); |
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441 | G4double proj_mass = pParticle->GetPDGMass(); |
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442 | |
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443 | G4double proj_energy = proj_mass + pTkin; |
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444 | G4double proj_momentum = std::sqrt(pTkin*(pTkin+2*proj_mass)); |
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445 | |
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446 | G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum ); |
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447 | |
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448 | sMand /= GeV*GeV; // in GeV for parametrisation |
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449 | proj_momentum /= GeV; |
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450 | proj_energy /= GeV; |
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451 | proj_mass /= GeV; |
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452 | |
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453 | // General PDG fit constants |
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454 | |
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455 | // G4double s0 = 5.38*5.38; // in Gev^2 |
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456 | // G4double eta1 = 0.458; |
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457 | // G4double eta2 = 0.458; |
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458 | // G4double B = 0.308; |
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459 | |
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460 | if( proj_momentum >= 10. ) // high energy: pp = nn = np |
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461 | // if( proj_momentum >= 2.) |
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462 | { |
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463 | Delta = 1.; |
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464 | if (proj_energy < 40.) Delta = 0.916+0.0021*proj_energy; |
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465 | |
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466 | if (proj_momentum >= 10.) { |
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467 | B0 = 7.5; |
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468 | A0 = 100. - B0*std::log(3.0e7); |
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469 | |
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470 | xsection = A0 + B0*std::log(proj_energy) - 11 |
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471 | + 103*std::pow(2*0.93827*proj_energy + proj_mass*proj_mass+ |
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472 | 0.93827*0.93827,-0.165); // mb |
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473 | } |
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474 | } |
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475 | else // low energy pp = nn != np |
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476 | { |
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477 | if(pParticle == tParticle) // pp or nn // nn to be pp |
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478 | { |
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479 | if( proj_momentum < 0.73 ) |
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480 | { |
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481 | hnXsc = 23 + 50*( std::pow( std::log(0.73/proj_momentum), 3.5 ) ); |
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482 | } |
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483 | else if( proj_momentum < 1.05 ) |
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484 | { |
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485 | hnXsc = 23 + 40*(std::log(proj_momentum/0.73))* |
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486 | (std::log(proj_momentum/0.73)); |
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487 | } |
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488 | else // if( proj_momentum < 10. ) |
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489 | { |
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490 | hnXsc = 39.0 + |
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491 | 75*(proj_momentum - 1.2)/(std::pow(proj_momentum,3.0) + 0.15); |
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492 | } |
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493 | xsection = hnXsc; |
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494 | } |
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495 | else // pn to be np |
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496 | { |
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497 | if( proj_momentum < 0.8 ) |
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498 | { |
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499 | hpXsc = 33+30*std::pow(std::log(proj_momentum/1.3),4.0); |
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500 | } |
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501 | else if( proj_momentum < 1.4 ) |
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502 | { |
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503 | hpXsc = 33+30*std::pow(std::log(proj_momentum/0.95),2.0); |
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504 | } |
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505 | else // if( proj_momentum < 10. ) |
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506 | { |
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507 | hpXsc = 33.3+ |
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508 | 20.8*(std::pow(proj_momentum,2.0)-1.35)/ |
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509 | (std::pow(proj_momentum,2.50)+0.95); |
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510 | } |
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511 | xsection = hpXsc; |
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512 | } |
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513 | } |
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514 | xsection *= millibarn; // parametrised in mb |
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515 | return xsection; |
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516 | } |
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517 | |
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518 | ///////////////////////////////////////////////////////////////////////////////// |
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519 | // |
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520 | // Returns hadron-nucleon inelastic cross-section based on FTF-parametrisation |
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521 | |
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522 | G4double |
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523 | G4GGNuclNuclCrossSection::GetHNinelasticXscVU(const G4DynamicParticle* aParticle, |
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524 | G4int At, G4int Zt) |
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525 | { |
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526 | G4int PDGcode = aParticle->GetDefinition()->GetPDGEncoding(); |
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527 | G4int absPDGcode = std::abs(PDGcode); |
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528 | G4double Elab = aParticle->GetTotalEnergy(); |
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529 | // (s - 2*0.88*GeV*GeV)/(2*0.939*GeV)/GeV; |
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530 | G4double Plab = aParticle->GetMomentum().mag(); |
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531 | // std::sqrt(Elab * Elab - 0.88); |
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532 | |
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533 | Elab /= GeV; |
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534 | Plab /= GeV; |
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535 | |
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536 | G4double LogPlab = std::log( Plab ); |
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537 | G4double sqrLogPlab = LogPlab * LogPlab; |
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538 | |
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539 | //G4cout<<"Plab = "<<Plab<<G4endl; |
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540 | |
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541 | G4double NumberOfTargetProtons = Zt; |
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542 | G4double NumberOfTargetNucleons = At; |
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543 | G4double NumberOfTargetNeutrons = NumberOfTargetNucleons - NumberOfTargetProtons; |
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544 | |
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545 | if(NumberOfTargetNeutrons < 0.) NumberOfTargetNeutrons = 0.; |
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546 | |
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547 | G4double Xtotal = 0., Xelastic = 0., Xinelastic =0.; |
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548 | |
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549 | if( absPDGcode > 1000 ) //------Projectile is baryon -------- |
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550 | { |
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551 | G4double XtotPP = 48.0 + 0. *std::pow(Plab, 0. ) + |
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552 | 0.522*sqrLogPlab - 4.51*LogPlab; |
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553 | |
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554 | G4double XtotPN = 47.3 + 0. *std::pow(Plab, 0. ) + |
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555 | 0.513*sqrLogPlab - 4.27*LogPlab; |
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556 | |
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557 | G4double XelPP = 11.9 + 26.9*std::pow(Plab,-1.21) + |
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558 | 0.169*sqrLogPlab - 1.85*LogPlab; |
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559 | |
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560 | G4double XelPN = 11.9 + 26.9*std::pow(Plab,-1.21) + |
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561 | 0.169*sqrLogPlab - 1.85*LogPlab; |
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562 | |
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563 | Xtotal = ( NumberOfTargetProtons * XtotPP + |
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564 | NumberOfTargetNeutrons * XtotPN ); |
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565 | |
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566 | Xelastic = ( NumberOfTargetProtons * XelPP + |
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567 | NumberOfTargetNeutrons * XelPN ); |
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568 | } |
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569 | |
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570 | Xinelastic = Xtotal - Xelastic; |
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571 | if(Xinelastic < 0.) Xinelastic = 0.; |
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572 | |
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573 | return Xinelastic*= millibarn; |
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574 | } |
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575 | |
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576 | /////////////////////////////////////////////////////////////////////////////// |
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577 | // |
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578 | // |
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579 | |
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580 | G4double |
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581 | G4GGNuclNuclCrossSection::GetNucleusRadius(const G4DynamicParticle* , |
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582 | const G4Element* anElement) |
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583 | { |
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584 | G4double At = anElement->GetN(); |
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585 | G4double oneThird = 1.0/3.0; |
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586 | G4double cubicrAt = std::pow (At, oneThird); |
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587 | |
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588 | G4double R; // = fRadiusConst*cubicrAt; |
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589 | R = fRadiusConst*cubicrAt; |
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590 | |
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591 | G4double meanA = 21.; |
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592 | G4double tauA1 = 40.; |
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593 | G4double tauA2 = 10.; |
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594 | G4double tauA3 = 5.; |
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595 | |
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596 | G4double a1 = 0.85; |
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597 | G4double b1 = 1. - a1; |
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598 | |
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599 | G4double b2 = 0.3; |
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600 | G4double b3 = 4.; |
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601 | |
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602 | if (At > 20.) // 20. |
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603 | { |
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604 | R *= ( a1 + b1*std::exp( -(At - meanA)/tauA1) ); |
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605 | } |
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606 | else if (At > 3.5) |
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607 | { |
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608 | R *= ( 1.0 + b2*( 1. - std::exp( (At - meanA)/tauA2) ) ); |
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609 | } |
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610 | else |
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611 | { |
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612 | R *= ( 1.0 + b3*( 1. - std::exp( (At - meanA)/tauA3) ) ); |
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613 | } |
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614 | |
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615 | return R; |
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616 | } |
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617 | |
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618 | /////////////////////////////////////////////////////////////////////////////// |
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619 | // |
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620 | // |
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621 | |
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622 | G4double |
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623 | G4GGNuclNuclCrossSection::GetNucleusRadius(G4double At) |
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624 | { |
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625 | G4double R; |
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626 | R = GetNucleusRadiusDE(At); |
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627 | |
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628 | return R; |
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629 | } |
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630 | |
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631 | /////////////////////////////////////////////////////////////////// |
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632 | |
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633 | G4double |
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634 | G4GGNuclNuclCrossSection::GetNucleusRadiusGG(G4double At) |
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635 | { |
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636 | G4double oneThird = 1.0/3.0; |
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637 | G4double cubicrAt = std::pow (At, oneThird); |
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638 | |
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639 | G4double R; // = fRadiusConst*cubicrAt; |
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640 | R = fRadiusConst*cubicrAt; |
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641 | |
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642 | G4double meanA = 20.; |
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643 | G4double tauA = 20.; |
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644 | |
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645 | if ( At > 20.) // 20. |
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646 | { |
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647 | R *= ( 0.8 + 0.2*std::exp( -(At - meanA)/tauA) ); |
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648 | } |
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649 | else |
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650 | { |
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651 | R *= ( 1.0 + 0.1*( 1. - std::exp( (At - meanA)/tauA) ) ); |
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652 | } |
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653 | |
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654 | return R; |
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655 | } |
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656 | |
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657 | |
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658 | G4double |
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659 | G4GGNuclNuclCrossSection::GetNucleusRadiusDE(G4double A) |
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660 | { |
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661 | // algorithm from diffuse-elastic |
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662 | |
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663 | G4double R, r0, a11, a12, a13, a2, a3; |
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664 | |
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665 | a11 = 1.26; // 1.08, 1.16 |
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666 | a12 = 1.; // 1.08, 1.16 |
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667 | a13 = 1.12; // 1.08, 1.16 |
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668 | a2 = 1.1; |
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669 | a3 = 1.; |
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670 | |
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671 | |
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672 | if (A < 50.) |
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673 | { |
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674 | if( 10 < A && A <= 15. ) r0 = a11*( 1 - std::pow(A, -2./3.) )*fermi; // 1.08*fermi; |
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675 | else if( 15 < A && A <= 20 ) r0 = a12*( 1 - std::pow(A, -2./3.) )*fermi; |
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676 | else if( 20 < A && A <= 30 ) r0 = a13*( 1 - std::pow(A, -2./3.) )*fermi; |
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677 | else r0 = a2*fermi; |
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678 | |
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679 | R = r0*std::pow( A, 1./3. ); |
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680 | } |
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681 | else |
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682 | { |
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683 | r0 = a3*fermi; |
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684 | |
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685 | R = r0*std::pow(A, 0.27); |
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686 | } |
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687 | return R; |
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688 | } |
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689 | |
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690 | |
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691 | /////////////////////////////////////////////////////////////////////////////// |
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692 | // |
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693 | // |
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694 | |
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695 | G4double G4GGNuclNuclCrossSection::CalculateEcmValue(const G4double mp, |
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696 | const G4double mt, |
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697 | const G4double Plab) |
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698 | { |
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699 | G4double Elab = std::sqrt ( mp * mp + Plab * Plab ); |
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700 | G4double Ecm = std::sqrt ( mp * mp + mt * mt + 2 * Elab * mt ); |
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701 | // G4double Pcm = Plab * mt / Ecm; |
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702 | // G4double KEcm = std::sqrt ( Pcm * Pcm + mp * mp ) - mp; |
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703 | |
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704 | return Ecm ; // KEcm; |
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705 | } |
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706 | |
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707 | |
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708 | /////////////////////////////////////////////////////////////////////////////// |
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709 | // |
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710 | // |
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711 | |
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712 | G4double G4GGNuclNuclCrossSection::CalcMandelstamS(const G4double mp, |
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713 | const G4double mt, |
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714 | const G4double Plab) |
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715 | { |
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716 | G4double Elab = std::sqrt ( mp * mp + Plab * Plab ); |
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717 | G4double sMand = mp*mp + mt*mt + 2*Elab*mt ; |
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718 | |
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719 | return sMand; |
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720 | } |
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721 | |
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722 | // |
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723 | // |
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724 | /////////////////////////////////////////////////////////////////////////////// |
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