[1197] | 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 7 | // * conditions of the Geant4 Software License, included in the file * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // |
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| 27 | // $Id: G4QProbability.cc,v 1.3 2009/09/04 16:13:19 mkossov Exp $ |
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[1340] | 28 | // GEANT4 tag $Name: hadr-chips-V09-03-08 $ |
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[1197] | 29 | // |
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| 30 | // ------------------------------------------------------------ |
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| 31 | // GEANT 4 class implementation file |
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| 32 | // |
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| 33 | // ---------------- G4QProbability ---------------- |
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| 34 | // by Mikhail Kossov Oct, 2006 |
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| 35 | // class for Pomeron & Reggeon amplitudes used by CHIPS |
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| 36 | // For comparison mirror member functions are taken from G4 class: |
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| 37 | // G4PomeronCrossSection |
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| 38 | // ------------------------------------------------------------------ |
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| 39 | // Short description: Pomeron is one of the possible vacuum pole (the |
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| 40 | // second is Oderon, but they are identical in the present model), by |
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| 41 | // which particle exchang in the ellastic scattering process. Others |
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| 42 | // are Reggeons and, possibly Instantons (for spin-flip reactions). |
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| 43 | // Strings are cuts of Pomerons and Reggeons (optic theorem connects |
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| 44 | // the amplitude of scattering at zero angle with the total inelastic |
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| 45 | // cross-section). They describe inelastic processes at high energies. |
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| 46 | // ------------------------------------------------------------------ |
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| 47 | |
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| 48 | #include "G4QProbability.hh" |
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| 49 | |
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| 50 | G4QProbability::G4QProbability(G4int PDG) |
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| 51 | { |
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| 52 | S0 = 1.*GeV*GeV; // Must be a constant (just GeV^2 unit !) |
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| 53 | pom_Alpha = 1.0808; // Must be the same for all hadrons |
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| 54 | pom_Alphaprime = 0.25/GeV/GeV; |
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| 55 | qex_Gamma = 9./GeV/GeV; |
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| 56 | qex_R2 = 27./GeV/GeV; |
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| 57 | qex_Alphaprime = 1.5/GeV/GeV; |
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| 58 | |
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| 59 | G4int aP = std::abs(PDG); |
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| 60 | if (PDG==2212 || PDG==2112) InitForNucleon(); |
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| 61 | else if(PDG==111 || aP==211) InitForPion(); |
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| 62 | else if(PDG==130 || PDG==310 || aP==311 || aP==321) InitForKaon(); |
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| 63 | else if(PDG==22) InitForGamma(); |
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| 64 | else if(PDG > 3000) InitForHyperon(); |
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| 65 | else if(PDG <-2000) InitForAntiBaryon(); |
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| 66 | else |
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| 67 | { |
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| 68 | G4cout<<"-Warning-G4QProbability is initialized for PDGCode="<<PDG<<" as Pion"<<G4endl; |
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| 69 | InitForPion(); |
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| 70 | } |
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| 71 | pom_sqC=std::sqrt(pom_C); |
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| 72 | } |
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| 73 | |
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| 74 | G4double G4QProbability::GetCutPomProbability(const G4double s, const G4double imp2, |
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| 75 | const G4int nPom) |
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| 76 | { |
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| 77 | static const G4int nft=11; |
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| 78 | static const G4int nf1=nft-1; |
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| 79 | static const G4double ft[nft]={1.,1.,2.,6.,24.,120.,720.,5040.,40320.,362880.,3628800.}; |
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| 80 | if(nPom<0) return 0.; |
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| 81 | G4double f=ft[nf1]; |
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| 82 | if(nPom<nft) f=ft[nPom]; |
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| 83 | else for(G4int i=nft; i<= nPom; i++) f*=i; // Calculate factorial for high nPom |
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| 84 | G4double e=PomEikonal(s,imp2); e+=e; // Doubled Eikonal |
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| 85 | return std::exp(-e)*std::pow(e,nPom)/pom_C/f; |
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| 86 | } |
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| 87 | |
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| 88 | G4double G4QProbability::GetCutQexProbability(const G4double s, const G4double imp2, |
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| 89 | const G4int nQex) |
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| 90 | { |
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| 91 | static const G4int nft=11; |
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| 92 | static const G4int nf1=nft-1; |
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| 93 | static const G4double ft[nft]={1.,1.,2.,6.,24.,120.,720.,5040.,40320.,362880.,3628800.}; |
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| 94 | if(nQex<0) return 0.; |
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| 95 | G4double f=ft[nf1]; |
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| 96 | if(nQex<nft) f=ft[nQex]; |
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| 97 | else for(G4int i=nft; i<= nQex; i++) f*=i; // Calculate factorial for high nPom |
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| 98 | G4double e=QexEikonal(s,imp2); e+=e; // Doubled Eikonal |
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| 99 | return std::exp(-e)*std::pow(e,nQex)/f; |
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| 100 | } |
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| 101 | |
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| 102 | void G4QProbability::InitForNucleon() |
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| 103 | { |
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| 104 | pom_Gamma = 2.16/GeV/GeV; // ? M.K.@@ Must be taken from total cross-sections |
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| 105 | pom_C = 1.4; |
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| 106 | pom_R2 = 3.30/GeV/GeV; |
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| 107 | } |
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| 108 | |
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| 109 | void G4QProbability::InitForHyperon() |
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| 110 | { |
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| 111 | pom_Gamma = 2.16/GeV/GeV; // ? M.K.@@ Must be taken from total cross-sections |
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| 112 | pom_C = 1.4; |
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| 113 | pom_R2 = 3.30/GeV/GeV; // ? M.K.@@ Just a guess |
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| 114 | } |
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| 115 | void G4QProbability::InitForAntiBaryon() |
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| 116 | { |
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| 117 | pom_Gamma = 2.16/GeV/GeV; // ? M.K.@@ Must be taken from total cross-sections |
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| 118 | pom_C = 1.4; |
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| 119 | pom_R2 = 3.30/GeV/GeV; |
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| 120 | } |
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| 121 | |
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| 122 | void G4QProbability::InitForPion() |
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| 123 | { |
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| 124 | pom_Gamma = 2.16/GeV/GeV; // ? M.K.@@ Must be taken from total cross-sections |
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| 125 | pom_C = 1.6; // Only: for mesons it is bigger than for baryons |
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| 126 | pom_R2 = 2.36/GeV/GeV; |
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| 127 | } |
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| 128 | |
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| 129 | void G4QProbability::InitForKaon() |
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| 130 | { |
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| 131 | pom_Gamma = 1.92/GeV/GeV; // ? M.K.@@ Must be taken from total cross-sections |
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| 132 | pom_C = 1.8; // 1.7 (?) |
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| 133 | pom_R2 = 1.96/GeV/GeV; // ? M.K.@@ Just a guess |
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| 134 | } |
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| 135 | |
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| 136 | void G4QProbability::InitForGamma() |
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| 137 | { |
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| 138 | pom_Gamma = 2.16/GeV/GeV; // ? M.K.@@ Must be taken from total cross-sections |
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| 139 | pom_C = 1.7; |
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| 140 | pom_R2 = 2.16/GeV/GeV; // ? M.K.@@ Just a guess |
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| 141 | } |
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| 142 | |
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| 143 | G4double G4QProbability::Expand(G4double z) |
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| 144 | { |
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| 145 | G4double sum=1.; |
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| 146 | G4double current=1.; |
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| 147 | for(G4int j=2; j<21; j++) |
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| 148 | { |
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| 149 | current *= -z*(j-1)/j/j; |
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| 150 | sum+=current; |
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| 151 | } |
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| 152 | return sum; |
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| 153 | } |
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| 154 | |
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| 155 | G4double G4QProbability::GetQexTotProbability(const G4double s, const G4double imp2) |
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| 156 | { |
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| 157 | G4double ExpPom=std::exp(-PomEikonal(s,imp2)); |
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| 158 | G4double ExpQex=std::exp(-QexEikonal(s,imp2)); |
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| 159 | G4double Amp=(ExpQex*(1.-ExpPom) + sqr(pom_sqC-1.)*ExpPom*(1.-ExpQex))/pom_C; |
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| 160 | return Amp+Amp; |
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| 161 | } |
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| 162 | |
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| 163 | G4double G4QProbability::GetQexElProbability(const G4double s, const G4double imp2) |
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| 164 | { |
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| 165 | G4double ExpPom=std::exp(-PomEikonal(s,imp2)); |
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| 166 | G4double ExpQex=std::exp(-QexEikonal(s,imp2)); |
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| 167 | G4double Amp=(ExpQex*(1.-ExpPom) + sqr(pom_sqC-1.)*ExpPom*(1.-ExpQex))/pom_C; |
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| 168 | return Amp*Amp; |
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| 169 | } |
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| 170 | |
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| 171 | G4double G4QProbability::GetQexDubDiffProbability(const G4double s, const G4double imp2) |
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| 172 | { |
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| 173 | G4double ExpPom=std::exp(-PomEikonal(s,imp2)); |
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| 174 | G4double ExpQex=std::exp(-QexEikonal(s,imp2)); |
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| 175 | G4double Amp=sqr(pom_sqC-1.)*(ExpQex*(1.-ExpPom) + ExpPom*(1.-ExpQex))/pom_C; |
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| 176 | return Amp*Amp; |
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| 177 | } |
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| 178 | |
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| 179 | G4double G4QProbability::GetQexSinDiffProbability(const G4double s, const G4double imp2) |
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| 180 | { |
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| 181 | G4double ExpPom=std::exp(-PomEikonal(s,imp2)); |
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| 182 | G4double ExpQex=std::exp(-QexEikonal(s,imp2)); |
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| 183 | G4double Amp=(pom_sqC-1.)*(ExpQex*(1.-ExpPom) - (pom_sqC-1.)*ExpPom*(1.-ExpQex))/pom_C; |
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| 184 | return Amp*Amp; |
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| 185 | } |
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| 186 | |
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| 187 | G4double G4QProbability::GetQexDiffProbability(const G4double s, const G4double imp2) |
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| 188 | { |
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| 189 | return GetQexDubDiffProbability(s,imp2)+2*GetQexSinDiffProbability(s,imp2); |
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| 190 | } |
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| 191 | |
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| 192 | G4double G4QProbability::GetQexInelProbability(const G4double s, const G4double imp2) |
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| 193 | { |
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| 194 | G4double ExpPom=std::exp(-PomEikonal(s,imp2)); |
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| 195 | G4double ExpQex=std::exp(-QexEikonal(s,imp2)); |
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| 196 | G4double Amp=sqr(pom_sqC-1.)*(ExpQex*(1.-ExpPom) + ExpPom*(1.-ExpQex))/pom_C; |
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| 197 | return Amp+Amp-Amp*Amp; |
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| 198 | } |
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