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 | // G4 Tools program: NuMu DIS (x,Q2) approximation is integrated over x |
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28 | // ..................................................... |
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29 | // Created: M.V. Kossov, CERN/ITEP(Moscow), 30-Sept-05 |
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30 | // |
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31 | //===================================================================== |
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32 | #include "globals.hh" |
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33 | #include <iostream> |
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34 | #include <fstream> |
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35 | #include <vector> |
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36 | #include "G4ios.hh" |
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37 | #include <CLHEP/GenericFunctions/LogGamma.hh> |
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38 | |
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39 | void strucf(int A, double x, double Q2, double& f2, double& xf3, double& fL) |
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40 | { |
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41 | //const double MN=.931494043; // Nucleon mass (inside nucleus, atomic mass unit, GeV) |
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42 | //const double MN2=MN*MN; // M_N^2 in GeV^2 |
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43 | //const double mpi=.13957018; // charged pi meson mass in GeV |
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44 | //const double Wt=MN+mpi; // Delta threshold |
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45 | //const double W2t=Wt*Wt; // Squared Delta threshold |
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46 | const Genfun::LogGamma lGam; |
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47 | static int mA=0; |
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48 | static double mQ2=0., mN, mD, mDel, mU2, mU3, mV; |
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49 | //static double mUU; |
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50 | double N=3., D=0., Del=0., U2=0., U3=0., V=0.; |
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51 | //double UU=0.; |
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52 | if(A==mA && Q2==mQ2) // Associative memory for acceleration |
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53 | { |
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54 | N =mN; |
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55 | D =mD; |
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56 | Del=mDel; |
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57 | U2 =mU2; |
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58 | U3 =mU3; |
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59 | //UU =mUU; |
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60 | V =mV; |
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61 | } |
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62 | else |
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63 | { |
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64 | double r=0.; |
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65 | double max=1.; |
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66 | double H=1.22; |
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67 | if(A==1) // Proton |
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68 | { |
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69 | r=std::sqrt(Q2/1.66); |
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70 | max=.5; |
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71 | } |
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72 | else if(A<13) // Light nuclei |
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73 | { |
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74 | double f=Q2/4.62; |
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75 | r=f*f; |
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76 | max=.3; |
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77 | if(A>2) H=1.; |
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78 | } |
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79 | else if(A>0) // Heavy nuclei |
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80 | { |
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81 | double f=Q2/3.4; |
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82 | double ff=f*f; |
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83 | r=ff*ff; |
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84 | max=.5; |
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85 | H=1.; |
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86 | } |
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87 | else G4cout<<"strucf: A="<<A<<" <= 0"<< G4endl; |
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88 | // |
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89 | N=3.+.3581*std::log(1.+Q2/.04); // a#of partons in the nonperturbative phase space |
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90 | Del=(1.+r)/(12.5+r/max); |
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91 | double S=std::pow(1.+.6/Q2,-1.-Del); |
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92 | D=H*S*(1.-.5*S); |
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93 | V=3*(1.-D)*(N-1.); |
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94 | double cc=Q2/.08; |
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95 | double cc2=cc*cc; |
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96 | //double C=(1.+cc2)/(1.+cc2/.24); // Weak? |
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97 | double C=(1.+cc2)/(1.+cc2/.24)/(1.+Q2/21.6); // EM |
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98 | double c3=C+C+C; |
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99 | double uu=std::exp(lGam(N-Del)-lGam(N-1.)-lGam(1.-Del))/N; |
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100 | U2=(c3+N-3.)*uu; |
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101 | U3=c3*uu; |
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102 | //UU=uu+uu+uu; // @@ |
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103 | mA = A; |
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104 | mQ2 = Q2; |
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105 | mN = N; |
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106 | mD = D; |
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107 | mDel=Del; |
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108 | mU2 =U2; |
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109 | mU3 =U3; |
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110 | //mUU =UU; // @@ |
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111 | mV =V; |
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112 | } |
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113 | // From here the Q2 coefficients are used |
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114 | double x1=std::pow(1.-x,N-2.); |
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115 | double pp=D*std::pow(x,-Del)*x1; |
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116 | double dir=V*x*x1; |
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117 | double per=U2*pp; |
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118 | f2 = per + dir; |
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119 | //double W2=MN2-MN2*x+Q2/x-Q2; |
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120 | //if(W2<W2t) |
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121 | //{ |
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122 | // per=UU*pp; |
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123 | // xf3= per+dir; |
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124 | //} |
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125 | //else |
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126 | xf3= U3*pp+dir; |
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127 | fL = per/4.; |
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128 | return; |
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129 | } |
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130 | |
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131 | void getFun(int A, double lx, double Q2, double* f) |
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132 | { |
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133 | double f2=0., xf3=0., fL=0.; |
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134 | if (lx>0.5) G4cerr<<"***getFun: ln(x)="<<lx<<">.5"<<G4endl; |
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135 | double x=std::exp(lx); |
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136 | double x2=x*x; |
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137 | strucf(A, x, Q2, f2, xf3, fL); |
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138 | f[0]=f2; // direct part |
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139 | f[1]=(-f2+xf3)/x; // *y (neutrino) part |
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140 | f[2]=(-f2-xf3)/x; // *y (anti-neutrino) part |
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141 | f[3]=(f2-fL-xf3)/x2; // *y2 (neutrino) part |
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142 | f[4]=(f2-fL+xf3)/x2; // *y2 (anti-neutrino) part |
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143 | } |
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144 | |
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145 | int main() |
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146 | { |
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147 | const double reps=.001; // relative accuracy of the total Q2 integral calculation |
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148 | const double xeps=.0001; // relative accuracy of the total X integral calculation |
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149 | // ========= |
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150 | const double GF=1.16637e-5; // Fermi constant in GeV^-2 |
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151 | const double GF2=GF*GF; // Squared Fermi constant in GeV^-4 |
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152 | const double MW=80.425; // Mass of W-boson in GeV |
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153 | const double MW2=MW*MW; // Squared mass of W-boson in GeV^2 |
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154 | const double MW4=MW2*MW2; // Quadro mass of W-boson in GeV^4 |
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155 | const double hc2=38937932300.;// (hc)^2 in GeV^2*10^-38cm2 to convert GeV^-2 to 10^-38cm2 |
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156 | const double pif=3.14159265*4;// 4pi |
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157 | const double sik=GF2*hc2/pif; // precalculated coefficient |
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158 | //const double mpi=.1349766; // pi0 meson mass in GeV |
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159 | const double mpi=.13957018; // charged pi meson mass in GeV |
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160 | //const double mpi2=mpi*mpi; // m_pi^2 in GeV^2 |
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161 | //const double me=.00051099892; // electron mass in GeV |
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162 | //const double me2=me*me; // m_e^2 in GeV^2 |
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163 | //const double hme2=me2/2; // .5*m_e^2 in GeV^2 |
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164 | const double mmu=.105658369; // mu meson mass in GeV |
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165 | const double mmu2=mmu*mmu; // m_mu^2 in GeV^2 |
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166 | const double hmmu2=mmu2/2; // .5*m_mu^2 in GeV^2 |
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167 | //const double mtau=1.777; // tau meson mass in GeV |
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168 | //const double mtau2=mtau*mtau; // m_tau^2 in GeV^2 |
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169 | //const double hmtau2=mtau2/2; // .5*m_e^2 in GeV^2 |
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170 | //const double mp=.93827203; // proton mass in GeV |
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171 | //const double mn=.93956536; // neutron mass in GeV |
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172 | //const double md=1.87561282; // deuteron mass in GeV |
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173 | const double MN=.931494043; // Nucleon mass (inside nucleus, atomic mass unit, GeV) |
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174 | //const double MN=(mn+mp)/2; // Nucleon mass (mean free) in GeV |
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175 | //const double MD=1.232; // proton mass in GeV |
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176 | //const double mp2=mp*mp; // m_p^2 in GeV^2 |
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177 | const double MN2=MN*MN; // M_N^2 in GeV^2 |
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178 | const double dMN=MN+MN; // 2*M_N in GeV |
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179 | const double dMN2=MN2+MN2; // 2*M_N^2 in GeV^2 |
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180 | const double fMN2=dMN2+dMN2; // 4*M_N^2 in GeV^2 |
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181 | //const double EminE=me+me2/dMN;// Threshold for muon production |
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182 | const double EminMu=mmu+mmu2/dMN; // Threshold for muon production |
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183 | //const double EminTau=mmu+mmu2/dMN; // Threshold for muon production |
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184 | // |
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185 | //const double mc=.3; // parameter of W>M+mc cut for Quasi-Elastic/Delta |
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186 | const double mc=mpi; // parameter of W>M+mc cut for Quasi-Elastic/Delta |
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187 | const double mcV=(dMN+mc)*mc; // constant of W>M+mc cut for Quasi-Elastic |
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188 | //std::ofstream fileNuMuX("NuMuXQ2.out", std::ios::out); |
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189 | //fileNuMuX.setf( std::ios::scientific, std::ios::floatfield ); |
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190 | // _____ Begin of Test Area |
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191 | //Genfun::LogGamma logGamma; |
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192 | //double n=4.9; |
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193 | //double g=exp(logGamma(n)); |
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194 | //G4cout<<"Gamma("<<n<<") = "<<g<<G4endl; |
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195 | // ^^^^^ End of Test Area |
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196 | // |
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197 | double f[5]; // A working array |
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198 | int A=12; // Neucleus for which calculations should be done |
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199 | double lEnuMin=std::log(EminMu); // Log of Minimum energy of neutrino |
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200 | double lEnuMax=std::log(300.); // Log of Maximum energy of neutrino |
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201 | int nE=20; |
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202 | double dlE=(lEnuMax-lEnuMin)/nE; |
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203 | lEnuMin+=dlE/10; |
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204 | lEnuMax+=dlE/5; |
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205 | G4cout<<"Emin="<<EminMu<<",lEi="<<lEnuMin<<",lEa="<<lEnuMax<<",dlE="<<dlE<<G4endl; |
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206 | for(double lEnu=lEnuMin; lEnu<lEnuMax; lEnu+=dlE) |
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207 | { |
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208 | double Enu=std::exp(lEnu); // Energy of neutrino/anti-neutrino |
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209 | double dEnu=Enu+Enu; // doubled energy of nu/anu |
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210 | double Enu2=Enu*Enu; // squared energy of nu/anu |
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211 | double Emu=Enu-mmu; // Free Energy of neutrino/anti-neutrino |
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212 | double Emu2=Emu*Emu; // squared energy of nu/anu |
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213 | double ME=Enu*MN; // M*E |
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214 | double dME=ME+ME; // 2*M*E |
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215 | double DIStsig=1.; // Total curent DIS cross-section to be integrated |
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216 | double DISmsig=1.e20; // Total remembered DIS cross-section |
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217 | double dEMN=(dEnu+MN)*ME; |
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218 | double MEm=ME-hmmu2; |
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219 | double sqE=Enu*std::sqrt(MEm*MEm-mmu2*MN2); |
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220 | double E2M=MN*Enu2-(Enu+MN)*hmmu2; |
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221 | double ymax=(E2M+sqE)/dEMN; |
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222 | double ymin=(E2M-sqE)/dEMN; |
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223 | double rmin=1.-ymin; |
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224 | double rhm2E=hmmu2/Enu2; |
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225 | double Q2min=(Enu2+Enu2)*(rmin-rhm2E-std::sqrt(rmin*rmin-rhm2E-rhm2E)); |
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226 | double Q2max=dME*ymax; |
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227 | // *** Additional notQE limit **** |
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228 | //double Q2nqe=Emu*dMN-mcV; |
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229 | //if(Q2max>Q2nqe) Q2max=Q2nqe; // !! only for not QE |
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230 | // *** End of notQE ^^^^^ |
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231 | int nQ2=8; |
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232 | //G4cout<<"*** E="<<Enu<<", Q2i="<<Q2min<<" < Q2a="<<Q2max<<", yi="<<ymin<<" < ya=" |
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233 | // <<ymax<<G4endl; |
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234 | //while(fabs(DIStsig-DISmsig)/DIStsig>reps) |
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235 | //{ |
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236 | DISmsig=DIStsig; |
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237 | DIStsig=0.; |
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238 | nQ2*=2; |
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239 | double dQ2=(Q2max-Q2min)/nQ2; |
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240 | if(dQ2>0) for(double Q2=Q2min+dQ2/2; Q2<Q2max; Q2+=dQ2) |
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241 | { |
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242 | double DISxint=1.; // Curent DIS x-integral |
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243 | double DISmint=1.e20; // Remembered DIS x-integral |
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244 | double Q2M=Q2+MW2; |
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245 | double dik=MW4/Q2M/Q2M; |
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246 | double qmc=Q2+mcV; |
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247 | double lXQES=std::log((std::sqrt(qmc*qmc+Q2*fMN2)-qmc)/dMN2); // Quasielastic boundary |
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248 | //double lXQES=log(Q2/(Q2+mcV)); // Quasielastic boundary (W=MN+m_c) |
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249 | //double xN=Q2/dME; |
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250 | double xN=Q2/MN/(Emu+std::sqrt(Emu2+Q2)); |
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251 | //double lXmin=log(xN/ymax); |
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252 | double lXmin=std::log(xN); |
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253 | double lXmax=0.; // QES is in DIS |
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254 | // ****** QE ******** |
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255 | if(lXQES>lXmin) lXmin=lXQES; // A cut which leaves only QES |
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256 | //if(lXQES<lXmax) lXmax=lXQES; // A cut which excludes QES (see above "notQE") |
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257 | // *** End of QE^^^^^ |
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258 | //double lXmax=lXQES; // Cut off quasielastic |
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259 | int nX=8; |
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260 | while(std::fabs(DISxint-DISmint)/DISxint>xeps) |
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261 | { |
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262 | DISmint=DISxint; |
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263 | DISxint=0.; |
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264 | nX*=2; |
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265 | double dlX=(lXmax-lXmin)/nX; |
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266 | for(double lX=lXmin+dlX/2; lX<lXmax; lX+=dlX) |
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267 | { |
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268 | getFun(A, lX, Q2, f); |
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269 | DISxint+=f[0]+f[0]+xN*(f[1]+f[1]+xN*f[3]); // neutrino |
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270 | //DISxint+=f[0]+f[0]+xN*(f[2]+f[2]+xN*f[4]); // anti-neutrino |
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271 | //G4cout<<f[0]<<","<<f[1]<<","<<f[2]<<","<<f[3]<<","<<f[4]<<G4endl; |
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272 | } |
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273 | DISxint*=dlX; |
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274 | //G4cout<<"--- E="<<Enu<<" --- Q2="<<Q2<<" --- nX="<<nX<<", iX="<<DISxint |
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275 | // <<", mX="<<DISmint<<", rX="<<(DISxint-DISmint)/DISxint<<G4endl; |
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276 | } |
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277 | //G4cout<<"(E="<<Enu<<"), r="<<Q2/Q2mx<<" "<<DISxint*dik*sik<<G4endl;//NoNormedByEn |
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278 | // QE |
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279 | G4cout<<"(E="<<Enu<<"), Q2="<<Q2<<" "<<DISxint*dik*sik<<G4endl;//Not Normed By En |
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280 | // notQE |
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281 | //G4cout<<"(E="<<Enu<<"), r="<<Q2/Q2max<<" "<<DISxint*dik*sik/Enu<<G4endl;//NormByE |
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282 | DIStsig+=DISxint*dik; |
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283 | } |
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284 | DIStsig*=dQ2; |
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285 | //G4cout<<"=== E="<<Enu<<" ===> nQ="<<nQ2<<", iQ="<<DIStsig<<", mQ="<<DISmsig |
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286 | // <<", rQ="<<(DIStsig-DISmsig)/DIStsig<<G4endl; |
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287 | //} |
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288 | DIStsig*=sik/Enu; |
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289 | G4cout<<"*** E="<<Enu<<",sig/E="<<DIStsig<<G4endl; |
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290 | } // End of the Enery LOOP |
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291 | // int np=0; |
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292 | //for(int m=0; m<2; m++) |
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293 | //{ |
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294 | // //fileNuMuX<<" static const G4double SH"<<n<<"[nH]={"<<G4endl<<" "; |
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295 | // //G4cout<<"**** A_high="<<m<<G4endl; |
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296 | // np=0; |
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297 | // int nC=14; |
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298 | // for(G4int en=0; en<nC; en++) |
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299 | // { |
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300 | // //G4double sig=1.; |
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301 | // np++; |
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302 | // //if(np==7) // Write by 7 number in brackets |
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303 | // //{ |
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304 | // // if(en==nC-1) fileNuMuX<<sig<<"};"<<G4endl; |
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305 | // // else fileNuMuX<<sig<<","<<G4endl<<" "; |
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306 | // //} |
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307 | // //else fileNuMuX<<sig<<","; |
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308 | // //if(np==7) np=0; |
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309 | // } // End of the point LOOP |
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310 | //} // End of the isotop LOOP |
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311 | return 0; |
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312 | } |
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