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: G4QFragmentation.cc,v 1.3 2007/05/02 14:59:55 gunter Exp $ |
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28 | // GEANT4 tag $Name: $ |
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29 | // |
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30 | // ----------------------------------------------------------------------------- |
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31 | // GEANT 4 class header file |
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32 | // |
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33 | // History: |
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34 | // Created by Mikhail Kossov, October 2006 |
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35 | // CHIPS QGS fragmentation class |
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36 | // For comparison mirror member functions are taken from G4 classes: |
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37 | // G4QGSParticipants |
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38 | // G4QGSModels |
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39 | // G4ExcitedStringDecay |
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40 | // ----------------------------------------------------------------------------- |
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41 | // |
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42 | |
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43 | //#define debug |
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44 | //#define pdebug |
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45 | //#define ppdebug |
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46 | |
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47 | #include "globals.hh" |
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48 | #include "G4QFragmentation.hh" |
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49 | #include "G4LorentzVector.hh" |
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50 | #include <utility> |
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51 | |
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52 | // Promoting model parameters from local variables class properties @@(? M.K.) |
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53 | |
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54 | // Definition of static parameters |
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55 | G4int G4QFragmentation::nCutMax=7; |
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56 | G4double G4QFragmentation::ThersholdParameter=450.*MeV; |
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57 | G4double G4QFragmentation::QGSMThershold=3.*GeV; |
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58 | G4double G4QFragmentation::theNucleonRadius=1.5*fermi; |
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59 | // Parameters of diffractional fragmentation |
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60 | G4double G4QFragmentation::widthOfPtSquare=-0.72*GeV*GeV; // pt -width2 forStringExcitation |
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61 | G4double G4QFragmentation::minExtraMass=250.*MeV;// minimum excitation mass |
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62 | G4double G4QFragmentation::minmass=250.*MeV; // mean pion transverse mass for Xmin |
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63 | |
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64 | G4QFragmentation::G4QFragmentation() : theNucleus(0) |
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65 | { |
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66 | // Construct Shortlived particles (needed after the 2006 Particles revolution) |
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67 | G4ShortLivedConstructor ShortLived; |
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68 | ShortLived.ConstructParticle(); |
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69 | } |
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70 | |
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71 | G4QFragmentation::~G4QFragmentation() {if(theNucleus) delete theNucleus;} |
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72 | |
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73 | G4QHadronVector* G4QFragmentation::Scatter(const G4QNucleus &aNucleus, |
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74 | const G4QHadron &aPrimary) |
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75 | { |
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76 | G4QStringVector* strings=0; |
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77 | |
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78 | G4QHadron thePrimary = aPrimary; |
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79 | |
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80 | G4LorentzRotation toZ; |
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81 | G4LorentzVector Ptmp=thePrimary.Get4Momentum(); |
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82 | toZ.rotateZ(-1*Ptmp.phi()); |
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83 | toZ.rotateY(-1*Ptmp.theta()); |
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84 | thePrimary.Set4Momentum(toZ*Ptmp); |
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85 | G4LorentzRotation toLab(toZ.inverse()); |
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86 | |
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87 | G4int attempts = 0, maxAttempts=20; |
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88 | while(!strings) |
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89 | { |
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90 | if (attempts++ > maxAttempts ) |
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91 | { |
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92 | G4cerr<<"***G4QFragmentation::Scatter: "<<attempts<<" to create a string ( > max=" |
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93 | <<maxAttempts<<") --> try to increase maxAttempts"<<G4endl; |
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94 | G4Exception("G4QFragmentation::Scatter:","72",FatalException,"StringCreation"); |
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95 | } |
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96 | InitModel(aNucleus,thePrimary); |
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97 | strings = GetStrings(); |
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98 | } |
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99 | |
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100 | G4QHadronVector* theResult = 0; |
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101 | G4double stringEnergy(0); |
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102 | for( unsigned astring=0; astring < strings->size(); astring++) |
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103 | { |
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104 | // rotate string to lab frame, models have it aligned to z |
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105 | stringEnergy += (*strings)[astring]->GetLeftParton()->Get4Momentum().t(); |
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106 | stringEnergy += (*strings)[astring]->GetRightParton()->Get4Momentum().t(); |
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107 | (*strings)[astring]->LorentzRotate(toLab); |
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108 | } |
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109 | #ifdef debug |
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110 | G4cout<<"G4QFragmentation::Scatter: Total string energy = "<<stringEnergy<<G4endl; |
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111 | #endif |
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112 | theResult = FragmentStrings(strings); |
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113 | std::for_each(strings->begin(), strings->end(), DeleteQString() ); |
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114 | delete strings; |
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115 | |
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116 | return theResult; |
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117 | } |
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118 | |
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119 | void G4QFragmentation::InitModel(const G4QNucleus& aNucleus,const G4QHadron& aProjectile) |
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120 | { |
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121 | static const G4double mProt = G4Proton::Proton()->GetPDGMass(); // Mass of proton |
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122 | Init(aNucleus.GetN(),aNucleus.GetZ()); |
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123 | theCurrentVelocity.setX(0); |
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124 | theCurrentVelocity.setY(0); |
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125 | // @@ "target Nucleon" == "Proton at rest" (M.K. ?) |
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126 | G4double nCons = 1; // 1 or baryon number of the projectile |
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127 | G4int projAbsB=std::abs(aProjectile.GetBaryonNumber()); // Baryon/anti-baryon |
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128 | if(projAbsB>1) nCons = projAbsB; |
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129 | G4LorentzVector proj4M = aProjectile.Get4Momentum(); |
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130 | G4double pz_per_projectile = proj4M.pz()/nCons; |
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131 | G4double e_per_projectile = proj4M.e()/nCons+mProt; // @@ Add mass of TargetProtonAtRest |
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132 | //G4double e_per_projectile = aProjectile.Get4Momentum()*aProjectile.Get4Momentum(); |
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133 | //e_per_projectile += proj4M.vect()*proj4M.vect(); |
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134 | //e_per_projectile /=nCons*nCons; |
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135 | //e_per_projectile = std::sqrt(e_per_projectile); |
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136 | //e_per_projectile += G4Proton::Proton()->GetPDGMass();//@@Add mass of TargetProtonAtRest |
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137 | G4double vz = pz_per_projectile/e_per_projectile; |
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138 | #ifdef debug |
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139 | G4cout<<"G4QFragmentation::Init: Projectile4M="<<proj4M<<", vz="<<vz<<G4endl; |
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140 | #endif |
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141 | theCurrentVelocity.setZ(vz); |
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142 | DoLorentzBoost(-theCurrentVelocity); |
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143 | G4LorentzVector Mom = proj4M; |
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144 | Mom.boost(-theCurrentVelocity); |
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145 | G4QHadron theProjectile(aProjectile.GetQPDG(),Mom); |
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146 | #ifdef debug |
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147 | G4cout<<"G4QFragmentation::Init: PreInteractionMomentum"<<Mom<<G4endl; |
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148 | #endif |
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149 | BuildInteractions(theProjectile); |
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150 | GetWoundedNucleus()->DoLorentzBoost(theCurrentVelocity); |
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151 | } |
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152 | |
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153 | G4QStringVector* G4QFragmentation::GetStrings() |
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154 | { |
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155 | G4QPartonPair* aPair; |
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156 | G4QStringVector* theStrings = new G4QStringVector; |
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157 | G4QString* aString=0; |
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158 | while((aPair = GetNextPartonPair())) // @@ At present no difference in stringBuild ? M.K. |
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159 | { |
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160 | if (aPair->GetCollisionType() == G4QPartonPair::DIFFRACTIVE) |
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161 | { |
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162 | aString = BuildString(aPair); // @@ ? |
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163 | #ifdef debug |
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164 | G4cout<<"G4QFragmentation::GetStrings:DifString4M="<<aString->Get4Momentum()<<G4endl; |
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165 | #endif |
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166 | } |
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167 | else |
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168 | { |
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169 | aString = BuildString(aPair); // @@ ? |
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170 | #ifdef debug |
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171 | G4cout<<"G4QFragmentation::GetStrings:SftString4M="<<aString->Get4Momentum()<<G4endl; |
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172 | #endif |
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173 | } |
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174 | aString->Boost(theCurrentVelocity); |
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175 | theStrings->push_back(aString); |
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176 | delete aPair; |
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177 | } |
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178 | #ifdef debug |
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179 | for(G4int i=0; i<theStrings->size(); i++) G4cout<<"G4QFragmentation::GetStrings:String #" |
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180 | <<i<<", 4M="<<(*theStrings)[i]->Get4Momentum()<<G4endl; |
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181 | #endif |
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182 | return theStrings; |
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183 | } |
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184 | |
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185 | void G4QFragmentation::BuildInteractions(const G4QHadron &thePrimary) |
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186 | { |
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187 | |
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188 | // Find the collisions and collition conditions |
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189 | G4QHadron* aProjectile = SelectInteractions(thePrimary); |
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190 | |
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191 | // now build the parton pairs |
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192 | SplitHadrons(); |
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193 | |
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194 | // soft collisions, ordering is vital |
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195 | PerformSoftCollisions(); |
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196 | |
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197 | // the rest is diffractive |
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198 | PerformDiffractiveCollisions(); |
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199 | |
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200 | // clean-up, if necessary |
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201 | std::for_each(theInteractions.begin(),theInteractions.end(), DeleteQInteraction()); |
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202 | theInteractions.clear(); |
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203 | std::for_each(theTargets.begin(), theTargets.end(), DeleteQHadron()); |
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204 | theTargets.clear(); |
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205 | delete aProjectile; |
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206 | } |
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207 | |
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208 | // |
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209 | G4QHadron* G4QFragmentation::SelectInteractions(const G4QHadron &thePrimary) |
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210 | { |
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211 | G4QHadron* aProjectile = new G4QHadron(thePrimary); |
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212 | G4QPomeron theProbability(thePrimary.GetPDGCode()); // must be data member |
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213 | G4double outerRadius = theNucleus->GetOuterRadius(); |
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214 | |
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215 | // Check reaction threshold |
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216 | theNucleus->StartLoop(); |
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217 | G4QHadron* pNucleon = theNucleus->GetNextNucleon(); |
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218 | G4LorentzVector aPrimaryMomentum=thePrimary.Get4Momentum(); |
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219 | G4double s = (aPrimaryMomentum + pNucleon->Get4Momentum()).mag2(); |
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220 | G4double primaryMass=thePrimary.GetMass(); |
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221 | G4double ThresholdMass = primaryMass + pNucleon->GetMass(); |
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222 | ModelMode = SOFT; |
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223 | if (sqr(ThresholdMass + ThersholdParameter) > s) |
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224 | { |
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225 | G4cerr<<"***G4QFragmentation::SelectInteractions: ThrM="<<ThresholdMass<<" + ThrPa=" |
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226 | <<ThersholdParameter<<" = "<<ThresholdMass+ThersholdParameter<<" > std::sqrt(s)=" |
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227 | <<std::sqrt(s)<<G4endl; |
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228 | G4Exception("G4QFragmentation::SelectInteractions:","72",FatalException,"LowEnergy"); |
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229 | } |
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230 | if (sqr(ThresholdMass + QGSMThershold) > s) // thus only diffractive in cascade! |
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231 | { |
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232 | #ifdef debug |
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233 | G4cout<<"G4QFragmentation::SelectInteractions: ThrM="<<ThresholdMass<<" + ThrQGS=" |
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234 | <<QGSMThershold<<" = "<<ThresholdMass+QGSMThershold<<" > std::sqrt(s)=" |
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235 | <<std::sqrt(s)<<" -> only Diffraction is possible"<<G4endl; // @@ to Quasmon |
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236 | #endif |
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237 | ModelMode = DIFFRACTIVE; |
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238 | } |
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239 | |
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240 | // first find the collisions HPW |
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241 | std::for_each(theInteractions.begin(),theInteractions.end(), DeleteQInteraction()); |
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242 | theInteractions.clear(); |
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243 | G4int totalCuts = 0; |
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244 | G4double impactUsed = 0; |
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245 | |
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246 | G4double eKin = aPrimaryMomentum.e()-primaryMass; // Primary kinetic energy ? GeV ? M.K. |
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247 | |
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248 | while(theInteractions.size() == 0) |
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249 | { |
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250 | // choose random impact parameter HPW |
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251 | std::pair<G4double, G4double> theImpactParameter; |
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252 | theImpactParameter = theNucleus->ChooseImpactXandY(outerRadius+theNucleonRadius); |
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253 | G4double impactX = theImpactParameter.first; |
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254 | G4double impactY = theImpactParameter.second; |
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255 | |
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256 | // loop over nuclei to find collissions HPW |
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257 | theNucleus->StartLoop(); |
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258 | G4int nucleonCount = 0; // debug |
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259 | //G4QFragmentation_NPart = 0; // ? M.K. |
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260 | while( (pNucleon = theNucleus->GetNextNucleon()) ) |
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261 | { |
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262 | if(totalCuts>1.5*eKin) break; |
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263 | nucleonCount++; // debug |
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264 | // Needs to be moved to Probability class @@@ |
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265 | G4double s = (aPrimaryMomentum + pNucleon->Get4Momentum()).mag2(); |
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266 | G4double Distance2 = sqr(impactX - pNucleon->GetPosition().x()) + |
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267 | sqr(impactY - pNucleon->GetPosition().y()); |
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268 | G4double Probability = theProbability.GetInelasticProbability(s, Distance2); |
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269 | // test for inelastic collision |
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270 | G4double rndNumber = G4UniformRand(); |
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271 | // ModelMode = DIFFRACTIVE; |
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272 | if (Probability > rndNumber) |
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273 | { |
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274 | #ifdef debug |
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275 | G4cout<<"G4QFragmentation::SelectInteractions: p="<<Probability<<", r="<<rndNumber |
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276 | <<", d="<<std::sqrt(Distance2)<<G4endl; |
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277 | #endif |
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278 | G4QHadron* aTarget = new G4QHadron(*pNucleon); |
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279 | //G4QFragmentation_NPart ++; // ? M.K. |
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280 | theTargets.push_back(aTarget); |
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281 | pNucleon=aTarget; |
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282 | if((theProbability.GetDiffractiveProbability(s,Distance2)/Probability > |
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283 | G4UniformRand() && (ModelMode==SOFT)) || ModelMode==DIFFRACTIVE) |
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284 | { |
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285 | // diffractive interaction occurs |
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286 | if(IsSingleDiffractive()) ExciteSingDiffParticipants(aProjectile, aTarget); |
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287 | else ExciteDiffParticipants(aProjectile, aTarget); |
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288 | G4QInteraction* aInteraction = new G4QInteraction(aProjectile); |
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289 | aInteraction->SetTarget(aTarget); |
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290 | theInteractions.push_back(aInteraction); |
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291 | aInteraction->SetNumberOfDiffractiveCollisions(1); |
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292 | totalCuts += 1; |
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293 | } |
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294 | else |
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295 | { |
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296 | // nondiffractive soft interaction occurs |
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297 | // sample nCut+1 (cut Pomerons) pairs of strings can be produced |
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298 | G4int nCut; |
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299 | G4double* running = new G4double[nCutMax]; |
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300 | running[0] = 0; |
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301 | for(nCut = 0; nCut < nCutMax; nCut++) |
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302 | { |
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303 | running[nCut] = theProbability.GetCutPomeronProbability(s, Distance2, nCut+1); |
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304 | if(nCut!=0) running[nCut] += running[nCut-1]; |
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305 | } |
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306 | G4double random = running[nCutMax-1]*G4UniformRand(); |
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307 | for(nCut = 0; nCut < nCutMax; nCut++) {if(running[nCut] > random) break;} |
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308 | delete [] running; |
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309 | nCut = 0; |
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310 | aTarget->IncrementCollisionCount(nCut+1); |
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311 | aProjectile->IncrementCollisionCount(nCut+1); |
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312 | G4QInteraction* aInteraction = new G4QInteraction(aProjectile); |
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313 | aInteraction->SetTarget(aTarget); |
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314 | aInteraction->SetNumberOfSoftCollisions(nCut+1); |
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315 | theInteractions.push_back(aInteraction); |
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316 | totalCuts += nCut+1; |
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317 | impactUsed=Distance2; |
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318 | } |
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319 | } |
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320 | } |
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321 | #ifdef debug |
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322 | G4cout<<"G4QFragmentation::SelectInteractions: NUCLEONCOUNT="<<nucleonCount<<G4endl; |
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323 | #endif |
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324 | } |
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325 | #ifdef debug |
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326 | G4cout<<"G4QFragmentation::SelectInteractions: CUTDEBUG="<<totalCuts |
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327 | <<", ImpactParameter="<<impactUsed<<G4endl; |
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328 | #endif |
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329 | return aProjectile; |
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330 | } |
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331 | |
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332 | void G4QFragmentation::PerformDiffractiveCollisions() |
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333 | { |
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334 | for(unsigned i = 0; i < theInteractions.size(); i++) |
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335 | { |
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336 | G4QInteraction* anIniteraction = theInteractions[i]; |
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337 | G4QHadron* aProjectile = anIniteraction->GetProjectile(); |
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338 | G4QParton* aParton = aProjectile->GetNextParton(); |
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339 | G4QPartonPair* aPartonPair; |
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340 | // projectile first |
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341 | if (aParton) |
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342 | { |
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343 | aPartonPair = new G4QPartonPair(aParton, aProjectile->GetNextAntiParton(), |
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344 | G4QPartonPair::DIFFRACTIVE, |
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345 | G4QPartonPair::PROJECTILE); |
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346 | thePartonPairs.push_back(aPartonPair); |
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347 | } |
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348 | // then target |
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349 | G4QHadron* aTarget = anIniteraction->GetTarget(); |
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350 | aParton = aTarget->GetNextParton(); |
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351 | if (aParton) |
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352 | { |
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353 | aPartonPair = new G4QPartonPair(aParton, aTarget->GetNextAntiParton(), |
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354 | G4QPartonPair::DIFFRACTIVE, |
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355 | G4QPartonPair::TARGET); |
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356 | thePartonPairs.push_back(aPartonPair); |
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357 | } |
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358 | } |
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359 | } |
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360 | |
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361 | void G4QFragmentation::PerformSoftCollisions() |
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362 | { |
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363 | G4QInteractionVector::iterator i; |
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364 | for(i = theInteractions.begin(); i != theInteractions.end(); i++) |
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365 | { |
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366 | G4QInteraction* anIniteraction = *i; |
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367 | G4QPartonPair* aPair=0; |
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368 | if (anIniteraction->GetNumberOfSoftCollisions()) |
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369 | { |
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370 | G4QHadron* pProjectile = anIniteraction->GetProjectile(); |
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371 | G4QHadron* pTarget = anIniteraction->GetTarget(); |
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372 | for (G4int j = 0; j < anIniteraction->GetNumberOfSoftCollisions(); j++) |
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373 | { |
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374 | aPair= new G4QPartonPair(pTarget->GetNextParton(),pProjectile->GetNextAntiParton(), |
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375 | G4QPartonPair::SOFT, G4QPartonPair::TARGET); |
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376 | thePartonPairs.push_back(aPair); |
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377 | aPair= new G4QPartonPair(pProjectile->GetNextParton(),pTarget->GetNextAntiParton(), |
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378 | G4QPartonPair::SOFT, G4QPartonPair::PROJECTILE); |
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379 | thePartonPairs.push_back(aPair); |
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380 | } |
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381 | delete *i; |
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382 | i=theInteractions.erase(i); |
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383 | i--; |
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384 | } |
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385 | } |
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386 | } |
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387 | |
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388 | G4QPartonPair* G4QFragmentation::GetNextPartonPair() |
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389 | { |
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390 | if(thePartonPairs.empty()) return 0; |
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391 | G4QPartonPair* result = thePartonPairs.back(); |
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392 | thePartonPairs.pop_back(); |
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393 | return result; |
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394 | } |
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395 | |
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396 | G4QHadronVector* G4QFragmentation::FragmentStrings(const G4QStringVector* theStrings) |
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397 | { |
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398 | G4QHadronVector* theResult = new G4QHadronVector; |
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399 | |
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400 | G4LorentzVector KTsum(0.,0.,0.); |
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401 | G4bool NeedEnergyCorrector=false; |
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402 | |
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403 | for( unsigned astring=0; astring < theStrings->size(); astring++) |
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404 | { |
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405 | KTsum+= (*theStrings)[astring]->Get4Momentum(); |
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406 | if(!(KTsum.e()<1.) && !(KTsum.e()>-1.)) |
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407 | { |
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408 | G4cerr<<"***G4QFragmentation::FragmentStrings: KTsum="<<KTsum<<G4endl; |
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409 | G4Exception("G4QFragmentation::FragmentStrings:","72",FatalException,"NANin3Vector"); |
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410 | } |
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411 | G4QHadronVector* generatedHadrons = 0; // A prototype of the string output |
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412 | if( (*theStrings)[astring]->IsExcited() ) |
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413 | { |
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414 | generatedHadrons=(*theStrings)[astring]->FragmentString(true);// Fragment QGSM String |
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415 | } |
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416 | else |
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417 | { |
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418 | //generatedHadrons = new G4QHadronVector; |
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419 | //generatedHadrons->push_back((*theStrings)[astring]->GetAsQHadron()); //@@ NotImplem |
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420 | } |
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421 | if (!generatedHadrons) |
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422 | { |
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423 | G4cerr<<"G4QFragmentation::FragmentStrings: No Hadrons produced" << G4endl; |
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424 | continue; |
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425 | } |
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426 | G4LorentzVector KTsum1(0.,0.,0.,0.); |
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427 | for(unsigned aTrack=0; aTrack<generatedHadrons->size(); aTrack++) |
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428 | { |
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429 | theResult->push_back((*generatedHadrons)[aTrack]); |
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430 | KTsum1+= (*generatedHadrons)[aTrack]->Get4Momentum(); |
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431 | } |
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432 | |
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433 | if(std::abs((KTsum1.e()-(*theStrings)[astring]->Get4Momentum().e())/KTsum1.e()) |
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434 | > perMillion) NeedEnergyCorrector=true; |
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435 | // clean up |
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436 | delete generatedHadrons; |
---|
437 | } |
---|
438 | #ifdef debug |
---|
439 | G4cout<<"G4QFragmentation::FragmentStrings: String4mom="<<KTsum<<endl; |
---|
440 | #endif |
---|
441 | if(NeedEnergyCorrector) EnergyAndMomentumCorrector(theResult, KTsum); |
---|
442 | return theResult; |
---|
443 | } |
---|
444 | |
---|
445 | G4bool G4QFragmentation::EnergyAndMomentumCorrector(G4QHadronVector* Output, |
---|
446 | G4LorentzVector& TotalCollisionMom) |
---|
447 | { |
---|
448 | const int nAttemptScale = 500; |
---|
449 | const double ErrLimit = 1.E-5; |
---|
450 | if (Output->empty()) return TRUE; |
---|
451 | G4LorentzVector SumMom; |
---|
452 | G4double SumMass = 0; |
---|
453 | G4double TotalCollisionMass = TotalCollisionMom.m(); |
---|
454 | if( !(TotalCollisionMass<1) && !(TotalCollisionMass>-1) ) |
---|
455 | { |
---|
456 | G4cerr<<"***G4QFragmentation::EnergyAndMomentumCorrect:M="<<TotalCollisionMass<<G4endl; |
---|
457 | G4Exception("G4QFragmentation::EnergyAndMomentumCorr:","72",FatalException,"NAN_totM"); |
---|
458 | } |
---|
459 | // Calculate sum hadron 4-momenta and summing hadron mass |
---|
460 | unsigned int cHadron; |
---|
461 | for(cHadron = 0; cHadron < Output->size(); cHadron++) |
---|
462 | { |
---|
463 | SumMom += Output->operator[](cHadron)->Get4Momentum(); |
---|
464 | if( !(SumMom<1) && !(SumMom>-1) ) |
---|
465 | { |
---|
466 | G4cerr<<"***G4QFragmentation::EnergyAndMomentumCorrector: SumMom="<<SumMom<<G4endl; |
---|
467 | G4Exception("G4QFragmentation::EnergyAndMomentumCorr:","72",FatalException,"NANMom"); |
---|
468 | } |
---|
469 | SumMass += (*Output)[cHadron]->GetMass(); |
---|
470 | if(!(SumMass<1) && !(SumMass>-1)) |
---|
471 | { |
---|
472 | G4cerr<<"***G4QFragmentation::EnergyAndMomentumCorrector: SumMass="<<SumMass<<G4endl; |
---|
473 | G4Exception("G4QFragmentation::EnergyAndMomentumCor:","72",FatalException,"NANMass"); |
---|
474 | } |
---|
475 | } |
---|
476 | // Cannot correct a single particle |
---|
477 | if(Output->size() < 2) return FALSE; |
---|
478 | if (SumMass > TotalCollisionMass) return FALSE; |
---|
479 | SumMass = SumMom.m2(); |
---|
480 | if (SumMass < 0) return FALSE; |
---|
481 | SumMass = std::sqrt(SumMass); |
---|
482 | // Compute c.m.s. hadron velocity and boost KTV to hadron c.m.s. |
---|
483 | G4ThreeVector Beta = -SumMom.boostVector(); |
---|
484 | G4int nOut=Output->size(); |
---|
485 | if(nOut) for(G4int o=0; o<nOut; o++) (*Output)[o]->Boost(Beta); |
---|
486 | // Scale total c.m.s. hadron energy (hadron system mass). |
---|
487 | // It should be equal interaction mass |
---|
488 | G4double Scale = 1; |
---|
489 | G4int cAttempt = 0; |
---|
490 | G4double Sum = 0; |
---|
491 | G4bool success = false; |
---|
492 | for(cAttempt = 0; cAttempt < nAttemptScale; cAttempt++) |
---|
493 | { |
---|
494 | Sum = 0; |
---|
495 | for(cHadron = 0; cHadron < Output->size(); cHadron++) |
---|
496 | { |
---|
497 | G4LorentzVector HadronMom = Output->operator[](cHadron)->Get4Momentum(); |
---|
498 | HadronMom.setVect(Scale*HadronMom.vect()); |
---|
499 | G4double E = std::sqrt(HadronMom.vect().mag2() + sqr((*Output)[cHadron]->GetMass())); |
---|
500 | HadronMom.setE(E); |
---|
501 | Output->operator[](cHadron)->Set4Momentum(HadronMom); |
---|
502 | Sum += E; |
---|
503 | } |
---|
504 | Scale = TotalCollisionMass/Sum; |
---|
505 | if (Scale - 1 <= ErrLimit) |
---|
506 | { |
---|
507 | success = true; |
---|
508 | break; |
---|
509 | } |
---|
510 | #ifdef debug |
---|
511 | G4cout<<"G4QFragmentation::EnergyAndMomentumCorrector: Scale-1="<<Scale-1<<", TotM=" |
---|
512 | <<TotalCollisionMass<<", Sum="<<Sum<<G4endl; |
---|
513 | #endif |
---|
514 | } |
---|
515 | if(!success) |
---|
516 | { |
---|
517 | G4cout<<"***G4QFragmentation::EnergyAndMomentumCorrector: Scale #1 at end of loop M=" |
---|
518 | <<TotalCollisionMass<<", S"<<Sum<<", Sc="<<Scale |
---|
519 | <<" Increase number of attempts or increase ERRLIMIT"<<G4endl; |
---|
520 | G4Exception("G4QFragmentation::SelectInteractions:","72",FatalException,"NotCorrect"); |
---|
521 | } |
---|
522 | // Compute c.m.s. interaction velocity and KTV back boost |
---|
523 | Beta = TotalCollisionMom.boostVector(); |
---|
524 | nOut=Output->size(); |
---|
525 | if(nOut) for(G4int o=0; o<nOut; o++) (*Output)[o]->Boost(Beta); |
---|
526 | return TRUE; |
---|
527 | } |
---|
528 | |
---|
529 | // Excite double diffractive string |
---|
530 | G4bool G4QFragmentation::ExciteDiffParticipants(G4QHadron* projectile, |
---|
531 | G4QHadron* target) const |
---|
532 | { |
---|
533 | G4LorentzVector Pprojectile=projectile->Get4Momentum(); |
---|
534 | G4double Mprojectile=projectile->GetMass() + minExtraMass; |
---|
535 | G4double Mprojectile2=Mprojectile*Mprojectile; |
---|
536 | G4LorentzVector Ptarget=target->Get4Momentum(); |
---|
537 | G4double Mtarget=target->GetMass() + minExtraMass; |
---|
538 | G4double Mtarget2=Mtarget*Mtarget; |
---|
539 | #ifdef debug |
---|
540 | G4cout<<"G4QFragm::ExciteDiffPartici:Ep="<<Pprojectile.e()<<",Et="<<Ptarget.e()<<G4endl; |
---|
541 | #endif |
---|
542 | // Transform momenta to cms and then rotate parallel to z axis; |
---|
543 | G4LorentzVector Psum=Pprojectile+Ptarget; |
---|
544 | G4LorentzRotation toCms(-Psum.boostVector()); // Boost Rotation to CMS |
---|
545 | G4LorentzVector Ptmp=toCms*Pprojectile; |
---|
546 | if(Ptmp.pz()<=0.) // "String" moving backwards in CMS, abort collision !! ? M.K. |
---|
547 | { |
---|
548 | #ifdef debug |
---|
549 | G4cout<<"G4QFragmentation::ExciteDiffParticipants: *1* abort Collision!! *1*"<<G4endl; |
---|
550 | #endif |
---|
551 | return false; |
---|
552 | } |
---|
553 | toCms.rotateZ(-Ptmp.phi()); |
---|
554 | toCms.rotateY(-Ptmp.theta()); |
---|
555 | #ifdef debug |
---|
556 | G4cout<<"G4QFragment::ExciteDiffParticipantts: Be4Boost Pproj="<<Pprojectile<<", Ptarg=" |
---|
557 | <<Ptarget<<G4endl; |
---|
558 | #endif |
---|
559 | G4LorentzRotation toLab(toCms.inverse()); // Boost Rotation to LabSys (LS) |
---|
560 | Pprojectile.transform(toCms); |
---|
561 | Ptarget.transform(toCms); |
---|
562 | #ifdef debug |
---|
563 | G4cout<< "G4QFragment::ExciteDiffParticipantts: AfterBoost Pproj="<<Pprojectile<<"Ptarg=" |
---|
564 | <<Ptarget<<", cms4M="<<Pprojectile+Ptarget<<G4endl; |
---|
565 | G4cout<<"G4QFragment::ExciteDiffParticipantts: ProjX+="<<Pprojectile.plus()<<", ProjX-=" |
---|
566 | <<Pprojectile.minus()<<", TargX+="<< Ptarget.plus()<<", TargX-="<<Ptarget.minus() |
---|
567 | <<G4endl; |
---|
568 | #endif |
---|
569 | G4LorentzVector Qmomentum(0.,0.,0.,0.); |
---|
570 | G4int whilecount=0; |
---|
571 | do |
---|
572 | { |
---|
573 | // Generate pt |
---|
574 | G4double maxPtSquare=sqr(Ptarget.pz()); |
---|
575 | if(whilecount++>=500 && whilecount%100==0) // @@ M.K. Hardwired limits |
---|
576 | #ifdef debug |
---|
577 | G4cout<<"G4QFragmentation::ExciteDiffParticipantts: can loop, loopCount="<<whilecount |
---|
578 | <<", maxPtSquare="<<maxPtSquare<<G4endl; |
---|
579 | #endif |
---|
580 | if(whilecount>1000) // @@ M.K. Hardwired limits |
---|
581 | { |
---|
582 | #ifdef debug |
---|
583 | G4cout<<"G4QFragmentation::ExciteDiffParticipants: *2* abort Loop!! *2*"<<G4endl; |
---|
584 | #endif |
---|
585 | return false; // Ignore this interaction |
---|
586 | } |
---|
587 | Qmomentum=G4LorentzVector(GaussianPt(widthOfPtSquare,maxPtSquare),0); |
---|
588 | #ifdef debug |
---|
589 | G4cout<<"G4QFragment::ExciteDiffParticipants: generated Pt="<<Qmomentum<<", ProjPt=" |
---|
590 | <<Pprojectile+Qmomentum<<", TargPt="<<Ptarget-Qmomentum<<G4endl; |
---|
591 | #endif |
---|
592 | // Momentum transfer |
---|
593 | G4double Xmin = minmass/(Pprojectile.e() + Ptarget.e()); |
---|
594 | G4double Xmax=1.; |
---|
595 | G4double Xplus =ChooseX(Xmin,Xmax); |
---|
596 | G4double Xminus=ChooseX(Xmin,Xmax); |
---|
597 | #ifdef debug |
---|
598 | G4cout<<"G4QFragment::ExciteDiffParticip: X-plus="<<Xplus<<",X-minus="<<Xminus<<G4endl; |
---|
599 | #endif |
---|
600 | G4double pt2=G4ThreeVector(Qmomentum.vect()).mag2(); |
---|
601 | G4double Qplus =-pt2/Xminus/Ptarget.minus(); |
---|
602 | G4double Qminus= pt2/Xplus /Pprojectile.plus(); |
---|
603 | Qmomentum.setPz((Qplus-Qminus)/2); |
---|
604 | Qmomentum.setE( (Qplus+Qminus)/2); |
---|
605 | #ifdef debug |
---|
606 | G4cout<<"G4QFragment::ExciteDiffParticip: Qplus="<<Qplus<<", Qminus="<<Qminus<<", pt2=" |
---|
607 | <<pt2<<", Qmomentum="<<Qmomentum<<", ProjM="<<(Pprojectile+Qmomentum).mag() |
---|
608 | <<", TargM="<<(Ptarget-Qmomentum).mag()<<G4endl; |
---|
609 | #endif |
---|
610 | } while((Pprojectile+Qmomentum).mag2()<=Mprojectile2 || |
---|
611 | (Ptarget-Qmomentum).mag2()<=Mtarget2); |
---|
612 | Pprojectile += Qmomentum; |
---|
613 | Ptarget -= Qmomentum; |
---|
614 | #ifdef debug |
---|
615 | G4cout<<"G4QFragment::ExciteDiffParticipan: Proj(Q)="<<Pprojectile<<", Targ(Q)="<<Ptarget |
---|
616 | <<", Proj(back)="<<toLab*Pprojectile<<", Targ(bac)="<< toLab*Ptarget << G4endl; |
---|
617 | #endif |
---|
618 | // Transform back and update SplitableHadron Participant. |
---|
619 | Pprojectile.transform(toLab); |
---|
620 | Ptarget.transform(toLab); |
---|
621 | #ifdef debug |
---|
622 | G4cout<< "G4QFragmentation::ExciteDiffParticipants: TargetMass="<<Ptarget.mag()<<G4endl; |
---|
623 | #endif |
---|
624 | target->Set4Momentum(Ptarget); |
---|
625 | #ifdef debug |
---|
626 | G4cout<<"G4QFragment::ExciteDiffParticipants:ProjectileMass="<<Pprojectile.mag()<<G4endl; |
---|
627 | #endif |
---|
628 | projectile->Set4Momentum(Pprojectile); |
---|
629 | return true; |
---|
630 | } // End of ExciteDiffParticipants |
---|
631 | |
---|
632 | |
---|
633 | // Excite single diffractive string |
---|
634 | G4bool G4QFragmentation::ExciteSingDiffParticipants(G4QHadron* projectile, |
---|
635 | G4QHadron* target) const |
---|
636 | { |
---|
637 | G4LorentzVector Pprojectile=projectile->Get4Momentum(); |
---|
638 | G4double Mprojectile=projectile->GetMass() + minExtraMass; |
---|
639 | G4double Mprojectile2=Mprojectile*Mprojectile; |
---|
640 | G4LorentzVector Ptarget=target->Get4Momentum(); |
---|
641 | G4double Mtarget=target->GetMass() + minExtraMass; |
---|
642 | G4double Mtarget2=Mtarget*Mtarget; |
---|
643 | #ifdef debug |
---|
644 | G4cout<<"G4QFragm::ExSingDiffPartici:Ep="<<Pprojectile.e()<<",Et="<<Ptarget.e()<<G4endl; |
---|
645 | #endif |
---|
646 | G4bool KeepProjectile= G4UniformRand() > 0.5; |
---|
647 | // Reset minMass of the non diffractive particle to its value, (minus for rounding...) |
---|
648 | if(KeepProjectile ) |
---|
649 | { |
---|
650 | #ifdef debug |
---|
651 | G4cout<<"--1/2--G4QFragmentation::ExSingDiffParticipants: Projectile is fixed"<<G4endl; |
---|
652 | #endif |
---|
653 | Mprojectile2 = projectile->GetMass2()*(1.-perCent); // Isn't it too big reduction? M.K. |
---|
654 | } |
---|
655 | else |
---|
656 | { |
---|
657 | #ifdef debug |
---|
658 | G4cout<<"---1/2---G4QFragmentation::ExSingDiffParticipants: Target is fixed"<<G4endl; |
---|
659 | #endif |
---|
660 | Mtarget2 = target->GetMass2()*(1.-perCent); // @@ Isn't it too big reduction? M.K. |
---|
661 | } |
---|
662 | // @@ From this point it repeats the Diffractional excitation (? Use flag ?) |
---|
663 | // Transform momenta to cms and then rotate parallel to z axis; |
---|
664 | G4LorentzVector Psum=Pprojectile+Ptarget; |
---|
665 | G4LorentzRotation toCms(-Psum.boostVector()); // Boost Rotation to CMS |
---|
666 | G4LorentzVector Ptmp=toCms*Pprojectile; |
---|
667 | if(Ptmp.pz()<=0.) // "String" moving backwards in CMS, abort collision !! ? M.K. |
---|
668 | { |
---|
669 | #ifdef debug |
---|
670 | G4cout<<"G4QFragment::ExciteSingDiffParticipants: *1* abort Collision!! *1*"<<G4endl; |
---|
671 | #endif |
---|
672 | return false; |
---|
673 | } |
---|
674 | toCms.rotateZ(-Ptmp.phi()); |
---|
675 | toCms.rotateY(-Ptmp.theta()); |
---|
676 | #ifdef debug |
---|
677 | G4cout<<"G4QFragm::ExciteSingDiffParticipantts: Be4Boost Pproj="<<Pprojectile<<",Ptarg=" |
---|
678 | <<Ptarget<<G4endl; |
---|
679 | #endif |
---|
680 | G4LorentzRotation toLab(toCms.inverse()); // Boost Rotation to LabSys (LS) |
---|
681 | Pprojectile.transform(toCms); |
---|
682 | Ptarget.transform(toCms); |
---|
683 | #ifdef debug |
---|
684 | G4cout<< "G4QFragment::ExciteDiffParticipantts: AfterBoost Pproj="<<Pprojectile<<"Ptarg=" |
---|
685 | <<Ptarget<<", cms4M="<<Pprojectile+Ptarget<<G4endl; |
---|
686 | |
---|
687 | G4cout<<"G4QFragment::ExciteDiffParticipantts: ProjX+="<<Pprojectile.plus()<<", ProjX-=" |
---|
688 | <<Pprojectile.minus()<<", TargX+="<< Ptarget.plus()<<", TargX-="<<Ptarget.minus() |
---|
689 | <<G4endl; |
---|
690 | #endif |
---|
691 | G4LorentzVector Qmomentum(0.,0.,0.,0.); |
---|
692 | G4int whilecount=0; |
---|
693 | do |
---|
694 | { |
---|
695 | // Generate pt |
---|
696 | G4double maxPtSquare=sqr(Ptarget.pz()); |
---|
697 | if(whilecount++>=500 && whilecount%100==0) // @@ M.K. Hardwired limits |
---|
698 | #ifdef debug |
---|
699 | G4cout<<"G4QFragment::ExciteSingDiffParticipantts: can loop, loopCount="<<whilecount |
---|
700 | <<", maxPtSquare="<<maxPtSquare<<G4endl; |
---|
701 | #endif |
---|
702 | if(whilecount>1000) // @@ M.K. Hardwired limits |
---|
703 | { |
---|
704 | #ifdef debug |
---|
705 | G4cout<<"G4QFragmentation::ExciteSingDiffParticipants: *2* abort Loop!! *2*"<<G4endl; |
---|
706 | #endif |
---|
707 | return false; // Ignore this interaction |
---|
708 | } |
---|
709 | Qmomentum=G4LorentzVector(GaussianPt(widthOfPtSquare,maxPtSquare),0); |
---|
710 | #ifdef debug |
---|
711 | G4cout<<"G4QFragm::ExciteSingDiffParticipants: generated Pt="<<Qmomentum<<", ProjPt=" |
---|
712 | <<Pprojectile+Qmomentum<<", TargPt="<<Ptarget-Qmomentum<<G4endl; |
---|
713 | #endif |
---|
714 | // Momentum transfer |
---|
715 | G4double Xmin = minmass/(Pprojectile.e() + Ptarget.e()); |
---|
716 | G4double Xmax=1.; |
---|
717 | G4double Xplus =ChooseX(Xmin,Xmax); |
---|
718 | G4double Xminus=ChooseX(Xmin,Xmax); |
---|
719 | #ifdef debug |
---|
720 | G4cout<<"G4QFragm::ExciteSingDiffPartici:X-plus="<<Xplus<<",X-minus="<<Xminus<<G4endl; |
---|
721 | #endif |
---|
722 | G4double pt2=G4ThreeVector(Qmomentum.vect()).mag2(); |
---|
723 | G4double Qplus =-pt2/Xminus/Ptarget.minus(); |
---|
724 | G4double Qminus= pt2/Xplus /Pprojectile.plus(); |
---|
725 | if (KeepProjectile) |
---|
726 | Qminus=(projectile->GetMass2()+pt2)/(Pprojectile.plus()+Qplus) - Pprojectile.minus(); |
---|
727 | else Qplus=Ptarget.plus() - (target->GetMass2()+pt2)/(Ptarget.minus()-Qminus); |
---|
728 | Qmomentum.setPz((Qplus-Qminus)/2); |
---|
729 | Qmomentum.setE( (Qplus+Qminus)/2); |
---|
730 | #ifdef debug |
---|
731 | G4cout<<"G4QFragm::ExciteDiffParticip: Qplus="<<Qplus<<", Qminus="<<Qminus<<", pt2=" |
---|
732 | <<pt2<<", Qmomentum="<<Qmomentum<<", ProjM="<<(Pprojectile+Qmomentum).mag() |
---|
733 | <<", TargM="<<(Ptarget-Qmomentum).mag()<<G4endl; |
---|
734 | #endif |
---|
735 | // while is different from the Double Diffractive Excitation (@@ !) |
---|
736 | //} while((Pprojectile+Qmomentum).mag2()<= Mprojectile2 || |
---|
737 | // (Ptarget-Qmomentum).mag2()<=Mtarget2); |
---|
738 | } while((Ptarget-Qmomentum).mag2()<=Mtarget2 || |
---|
739 | (Pprojectile+Qmomentum).mag2()<=Mprojectile2 || |
---|
740 | (Ptarget-Qmomentum).e() < 0. || (Pprojectile+Qmomentum).e() < 0.); |
---|
741 | Pprojectile += Qmomentum; |
---|
742 | Ptarget -= Qmomentum; |
---|
743 | #ifdef debug |
---|
744 | G4cout<<"G4QFragmentation::ExciteSingDiffParticipan: Proj(Q)="<<Pprojectile<<"(E=" |
---|
745 | <<Pprojectile.e()<<"), Targ(Q)="<<Ptarget<<"(E="<<Ptarget.e() |
---|
746 | <<"), Proj(back)="<<toLab*Pprojectile<<", Targ(bac)="<< toLab*Ptarget << G4endl; |
---|
747 | #endif |
---|
748 | // Transform back and update SplitableHadron Participant. |
---|
749 | Pprojectile.transform(toLab); |
---|
750 | Ptarget.transform(toLab); |
---|
751 | #ifdef debug |
---|
752 | G4cout<< "G4QFragm::ExciteSingDiffParticipants: TargetMass="<<Ptarget.mag()<<G4endl; |
---|
753 | #endif |
---|
754 | target->Set4Momentum(Ptarget); |
---|
755 | #ifdef debug |
---|
756 | G4cout<<"G4QFragm::ExciteDiffParticipants:ProjectileMass="<<Pprojectile.mag()<<G4endl; |
---|
757 | #endif |
---|
758 | projectile->Set4Momentum(Pprojectile); |
---|
759 | return true; |
---|
760 | } // End of ExciteSingleDiffParticipants |
---|
761 | |
---|
762 | void G4QFragmentation::SetParameters(G4int nCM, G4double thresh, G4double QGSMth, |
---|
763 | G4double radNuc, G4double SigPt, G4double extraM, G4double minM) |
---|
764 | {// ============================================================================= |
---|
765 | nCutMax = nCM; // max number of pomeron cuts |
---|
766 | ThersholdParameter = thresh; // internal threshold |
---|
767 | QGSMThershold = QGSMth; // QGSM threshold |
---|
768 | theNucleonRadius = radNuc; // effective radius of the nucleon inside Nucleus |
---|
769 | widthOfPtSquare = -2*SigPt*SigPt; // width^2 of pt for string excitation |
---|
770 | minExtraMass = extraM; // minimum excitation mass |
---|
771 | minmass = minM; // mean pion transverse mass; used for Xmin |
---|
772 | } |
---|
773 | |
---|
774 | G4double G4QFragmentation::ChooseX(G4double Xmin, G4double Xmax) const |
---|
775 | { |
---|
776 | // choose an x between Xmin and Xmax with P(x) ~ 1/x |
---|
777 | // to be improved... |
---|
778 | G4double range=Xmax-Xmin; |
---|
779 | if( Xmin<= 0. || range <=0.) |
---|
780 | { |
---|
781 | G4cerr<<"***G4QFragmentation::ChooseX: Xmin="<<Xmin<<", Xmax="<<Xmax<< G4endl; |
---|
782 | G4Exception("G4QFragmentation::ChooseX:","72",FatalException,"BadXRange"); |
---|
783 | } |
---|
784 | G4double x; |
---|
785 | do {x=Xmin+G4UniformRand()*range;} while ( Xmin/x < G4UniformRand() ); |
---|
786 | #ifdef debug |
---|
787 | G4cout<<"G4QFragmentation::ChooseX: DiffractiveX="<<x<<G4endl; |
---|
788 | #endif |
---|
789 | return x; |
---|
790 | } // End of ChooseX |
---|
791 | |
---|
792 | // Pt distribution @@ one can use 1/(1+A*Pt^2)^B |
---|
793 | G4ThreeVector G4QFragmentation::GaussianPt(G4double widthSq, G4double maxPtSquare) const |
---|
794 | { |
---|
795 | G4double pt2; do{pt2=widthSq*std::log(G4UniformRand());} while (pt2>maxPtSquare); |
---|
796 | pt2=std::sqrt(pt2); |
---|
797 | G4double phi=G4UniformRand()*twopi; |
---|
798 | return G4ThreeVector(pt2*std::cos(phi),pt2*std::sin(phi),0.); |
---|
799 | } // End of GaussianPt |
---|