[819] | 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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[962] | 26 | // $Id: G4RPGPiPlusInelastic.cc,v 1.4 2008/05/05 21:21:55 dennis Exp $ |
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[1340] | 27 | // GEANT4 tag $Name: geant4-09-03-ref-09 $ |
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[819] | 28 | // |
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| 29 | |
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| 30 | #include "G4RPGPiPlusInelastic.hh" |
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| 31 | #include "Randomize.hh" |
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| 32 | |
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[962] | 33 | G4HadFinalState* |
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| 34 | G4RPGPiPlusInelastic::ApplyYourself(const G4HadProjectile& aTrack, |
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| 35 | G4Nucleus& targetNucleus) |
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| 36 | { |
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| 37 | const G4HadProjectile *originalIncident = &aTrack; |
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| 38 | if (originalIncident->GetKineticEnergy()<= 0.1) { |
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| 39 | theParticleChange.SetStatusChange(isAlive); |
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| 40 | theParticleChange.SetEnergyChange(aTrack.GetKineticEnergy()); |
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| 41 | theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit()); |
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| 42 | return &theParticleChange; |
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| 43 | } |
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[819] | 44 | |
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| 45 | // create the target particle |
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| 46 | |
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| 47 | G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle(); |
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| 48 | G4ReactionProduct targetParticle( originalTarget->GetDefinition() ); |
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| 49 | |
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| 50 | G4ReactionProduct currentParticle( |
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| 51 | const_cast<G4ParticleDefinition *>(originalIncident->GetDefinition() ) ); |
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| 52 | currentParticle.SetMomentum( originalIncident->Get4Momentum().vect() ); |
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| 53 | currentParticle.SetKineticEnergy( originalIncident->GetKineticEnergy() ); |
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| 54 | |
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| 55 | // Fermi motion and evaporation |
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| 56 | // As of Geant3, the Fermi energy calculation had not been Done |
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| 57 | |
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| 58 | G4double ek = originalIncident->GetKineticEnergy(); |
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| 59 | G4double amas = originalIncident->GetDefinition()->GetPDGMass(); |
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| 60 | |
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| 61 | G4double tkin = targetNucleus.Cinema( ek ); |
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| 62 | ek += tkin; |
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| 63 | currentParticle.SetKineticEnergy( ek ); |
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| 64 | G4double et = ek + amas; |
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| 65 | G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) ); |
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| 66 | G4double pp = currentParticle.GetMomentum().mag(); |
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| 67 | if( pp > 0.0 ) |
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| 68 | { |
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| 69 | G4ThreeVector momentum = currentParticle.GetMomentum(); |
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| 70 | currentParticle.SetMomentum( momentum * (p/pp) ); |
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| 71 | } |
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| 72 | |
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| 73 | // calculate black track energies |
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| 74 | |
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| 75 | tkin = targetNucleus.EvaporationEffects( ek ); |
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| 76 | ek -= tkin; |
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| 77 | currentParticle.SetKineticEnergy( ek ); |
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| 78 | et = ek + amas; |
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| 79 | p = std::sqrt( std::abs((et-amas)*(et+amas)) ); |
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| 80 | pp = currentParticle.GetMomentum().mag(); |
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| 81 | if( pp > 0.0 ) |
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| 82 | { |
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| 83 | G4ThreeVector momentum = currentParticle.GetMomentum(); |
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| 84 | currentParticle.SetMomentum( momentum * (p/pp) ); |
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| 85 | } |
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| 86 | |
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| 87 | G4ReactionProduct modifiedOriginal = currentParticle; |
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| 88 | |
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| 89 | currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere |
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| 90 | targetParticle.SetSide( -1 ); // target always goes in backward hemisphere |
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| 91 | G4bool incidentHasChanged = false; |
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| 92 | G4bool targetHasChanged = false; |
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| 93 | G4bool quasiElastic = false; |
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| 94 | G4FastVector<G4ReactionProduct,256> vec; // vec will contain the secondary particles |
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| 95 | G4int vecLen = 0; |
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| 96 | vec.Initialize( 0 ); |
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| 97 | |
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[962] | 98 | const G4double cutOff = 0.1; |
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[819] | 99 | if( currentParticle.GetKineticEnergy() > cutOff ) |
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[962] | 100 | InitialCollision(vec, vecLen, currentParticle, targetParticle, |
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| 101 | incidentHasChanged, targetHasChanged); |
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[819] | 102 | |
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| 103 | CalculateMomenta( vec, vecLen, |
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| 104 | originalIncident, originalTarget, modifiedOriginal, |
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| 105 | targetNucleus, currentParticle, targetParticle, |
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| 106 | incidentHasChanged, targetHasChanged, quasiElastic ); |
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| 107 | |
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| 108 | SetUpChange( vec, vecLen, |
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| 109 | currentParticle, targetParticle, |
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| 110 | incidentHasChanged ); |
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| 111 | |
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| 112 | delete originalTarget; |
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| 113 | return &theParticleChange; |
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[962] | 114 | } |
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| 115 | |
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| 116 | |
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| 117 | // Initial Collision |
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| 118 | // selects the particle types arising from the initial collision of |
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| 119 | // the projectile and target nucleon. Secondaries are assigned to |
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| 120 | // forward and backward reaction hemispheres, but final state energies |
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| 121 | // and momenta are not calculated here. |
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[819] | 122 | |
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[962] | 123 | void |
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| 124 | G4RPGPiPlusInelastic::InitialCollision(G4FastVector<G4ReactionProduct,256>& vec, |
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| 125 | G4int& vecLen, |
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| 126 | G4ReactionProduct& currentParticle, |
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| 127 | G4ReactionProduct& targetParticle, |
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| 128 | G4bool& incidentHasChanged, |
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| 129 | G4bool& targetHasChanged) |
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| 130 | { |
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| 131 | G4double KE = currentParticle.GetKineticEnergy()/GeV; |
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| 132 | |
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| 133 | G4int mult; |
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| 134 | G4int partType; |
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| 135 | std::vector<G4int> fsTypes; |
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| 136 | |
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| 137 | G4double testCharge; |
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| 138 | G4double testBaryon; |
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| 139 | G4double testStrange; |
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| 140 | |
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| 141 | // Get particle types according to incident and target types |
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| 142 | |
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| 143 | if (targetParticle.GetDefinition() == particleDef[pro]) { |
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| 144 | mult = GetMultiplicityT32(KE); |
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| 145 | fsTypes = GetFSPartTypesForPipP(mult, KE); |
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| 146 | partType = fsTypes[0]; |
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| 147 | if (partType != pro) { |
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| 148 | targetHasChanged = true; |
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| 149 | targetParticle.SetDefinition(particleDef[partType]); |
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[819] | 150 | } |
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[962] | 151 | |
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| 152 | testCharge = 2.0; |
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| 153 | testBaryon = 1.0; |
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| 154 | testStrange = 0.0; |
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| 155 | |
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| 156 | } else { // target was a neutron |
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| 157 | mult = GetMultiplicityT12(KE); |
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| 158 | fsTypes = GetFSPartTypesForPipN(mult, KE); |
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| 159 | partType = fsTypes[0]; |
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| 160 | if (partType != neu) { |
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| 161 | targetHasChanged = true; |
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| 162 | targetParticle.SetDefinition(particleDef[partType]); |
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[819] | 163 | } |
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[962] | 164 | |
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| 165 | testCharge = 1.0; |
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| 166 | testBaryon = 1.0; |
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| 167 | testStrange = 0.0; |
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[819] | 168 | } |
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| 169 | |
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[962] | 170 | // Remove target particle from list |
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| 171 | |
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| 172 | fsTypes.erase(fsTypes.begin()); |
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| 173 | |
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| 174 | // See if the incident particle changed type |
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| 175 | |
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| 176 | G4int choose = -1; |
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| 177 | for(G4int i=0; i < mult-1; ++i ) { |
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| 178 | partType = fsTypes[i]; |
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| 179 | if (partType == pip) { |
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| 180 | choose = i; |
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| 181 | break; |
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| 182 | } |
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| 183 | } |
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| 184 | if (choose == -1) { |
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| 185 | incidentHasChanged = true; |
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| 186 | choose = G4int(G4UniformRand()*(mult-1) ); |
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| 187 | partType = fsTypes[choose]; |
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| 188 | currentParticle.SetDefinition(particleDef[partType]); |
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| 189 | } |
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| 190 | fsTypes.erase(fsTypes.begin()+choose); |
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| 191 | |
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| 192 | // Remaining particles are secondaries. Put them into vec. |
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| 193 | // Improve this by randomizing secondary order, then alternate |
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| 194 | // which secondary is put into forward or backward hemisphere |
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| 195 | |
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| 196 | G4ReactionProduct* rp(0); |
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| 197 | for(G4int i=0; i < mult-2; ++i ) { |
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| 198 | partType = fsTypes[i]; |
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| 199 | rp = new G4ReactionProduct(); |
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| 200 | rp->SetDefinition(particleDef[partType]); |
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| 201 | (G4UniformRand() < 0.5) ? rp->SetSide(-1) : rp->SetSide(1); |
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| 202 | if (partType > pim && partType < pro) rp->SetMayBeKilled(false); // kaons |
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| 203 | vec.SetElement(vecLen++, rp); |
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| 204 | } |
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[819] | 205 | |
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[962] | 206 | // if (mult == 2 && !incidentHasChanged && !targetHasChanged) |
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| 207 | // quasiElastic = true; |
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| 208 | |
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| 209 | // Check conservation of charge, strangeness, baryon number |
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| 210 | |
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| 211 | CheckQnums(vec, vecLen, currentParticle, targetParticle, |
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| 212 | testCharge, testBaryon, testStrange); |
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| 213 | |
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| 214 | return; |
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| 215 | } |
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