[824] | 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: G4PhaseSpaceDecayChannel.cc,v 1.13 2007/10/06 06:49:29 kurasige Exp $ |
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| 28 | // GEANT4 tag $Name: $ |
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| 29 | // |
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| 30 | // |
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| 31 | // ------------------------------------------------------------ |
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| 32 | // GEANT 4 class header file |
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| 33 | // |
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| 34 | // History: first implementation, based on object model of |
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| 35 | // 27 July 1996 H.Kurashige |
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| 36 | // 20 Oct 1996 H.Kurashige |
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| 37 | // 30 May 1997 H.Kurashige |
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| 38 | // ------------------------------------------------------------ |
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| 39 | |
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| 40 | #include "G4ParticleDefinition.hh" |
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| 41 | #include "G4DecayProducts.hh" |
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| 42 | #include "G4VDecayChannel.hh" |
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| 43 | #include "G4PhaseSpaceDecayChannel.hh" |
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| 44 | #include "Randomize.hh" |
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| 45 | #include "G4LorentzVector.hh" |
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| 46 | #include "G4LorentzRotation.hh" |
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| 47 | |
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| 48 | |
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| 49 | G4PhaseSpaceDecayChannel::G4PhaseSpaceDecayChannel(G4int Verbose) |
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| 50 | :G4VDecayChannel("Phase Space", Verbose) |
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| 51 | { |
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| 52 | |
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| 53 | } |
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| 54 | |
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| 55 | G4PhaseSpaceDecayChannel::G4PhaseSpaceDecayChannel( |
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| 56 | const G4String& theParentName, |
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| 57 | G4double theBR, |
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| 58 | G4int theNumberOfDaughters, |
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| 59 | const G4String& theDaughterName1, |
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| 60 | const G4String& theDaughterName2, |
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| 61 | const G4String& theDaughterName3, |
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| 62 | const G4String& theDaughterName4 ) |
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| 63 | :G4VDecayChannel("Phase Space", |
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| 64 | theParentName,theBR, |
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| 65 | theNumberOfDaughters, |
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| 66 | theDaughterName1, |
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| 67 | theDaughterName2, |
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| 68 | theDaughterName3, |
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| 69 | theDaughterName4) |
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| 70 | { |
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| 71 | |
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| 72 | } |
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| 73 | |
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| 74 | G4PhaseSpaceDecayChannel::~G4PhaseSpaceDecayChannel() |
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| 75 | { |
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| 76 | } |
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| 77 | |
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| 78 | G4DecayProducts *G4PhaseSpaceDecayChannel::DecayIt(G4double parentMass) |
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| 79 | { |
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| 80 | #ifdef G4VERBOSE |
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| 81 | if (GetVerboseLevel()>1) G4cout << "G4PhaseSpaceDecayChannel::DecayIt "; |
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| 82 | #endif |
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| 83 | |
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| 84 | G4DecayProducts * products = 0; |
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| 85 | |
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| 86 | if (parent == 0) FillParent(); |
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| 87 | if (daughters == 0) FillDaughters(); |
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| 88 | |
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| 89 | if (parentMass >0.0) parent_mass = parentMass; |
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| 90 | switch (numberOfDaughters){ |
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| 91 | case 0: |
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| 92 | #ifdef G4VERBOSE |
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| 93 | if (GetVerboseLevel()>0) { |
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| 94 | G4cout << "G4PhaseSpaceDecayChannel::DecayIt "; |
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| 95 | G4cout << " daughters not defined " <<G4endl; |
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| 96 | } |
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| 97 | #endif |
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| 98 | break; |
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| 99 | case 1: |
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| 100 | products = OneBodyDecayIt(); |
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| 101 | break; |
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| 102 | case 2: |
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| 103 | products = TwoBodyDecayIt(); |
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| 104 | break; |
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| 105 | case 3: |
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| 106 | products = ThreeBodyDecayIt(); |
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| 107 | break; |
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| 108 | default: |
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| 109 | products = ManyBodyDecayIt(); |
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| 110 | break; |
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| 111 | } |
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| 112 | #ifdef G4VERBOSE |
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| 113 | if ((products == 0) && (GetVerboseLevel()>0)) { |
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| 114 | G4cout << "G4PhaseSpaceDecayChannel::DecayIt "; |
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| 115 | G4cout << *parent_name << " can not decay " << G4endl; |
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| 116 | DumpInfo(); |
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| 117 | } |
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| 118 | #endif |
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| 119 | return products; |
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| 120 | } |
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| 121 | |
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| 122 | G4DecayProducts *G4PhaseSpaceDecayChannel::OneBodyDecayIt() |
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| 123 | { |
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| 124 | #ifdef G4VERBOSE |
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| 125 | if (GetVerboseLevel()>1) G4cout << "G4PhaseSpaceDecayChannel::OneBodyDecayIt()"<<G4endl; |
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| 126 | #endif |
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| 127 | |
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| 128 | //create parent G4DynamicParticle at rest |
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| 129 | G4ThreeVector dummy; |
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| 130 | G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0); |
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| 131 | //create G4Decayproducts |
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| 132 | G4DecayProducts *products = new G4DecayProducts(*parentparticle); |
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| 133 | delete parentparticle; |
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| 134 | |
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| 135 | //create daughter G4DynamicParticle at rest |
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| 136 | G4DynamicParticle * daughterparticle = new G4DynamicParticle( daughters[0], dummy, 0.0); |
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| 137 | products->PushProducts(daughterparticle); |
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| 138 | |
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| 139 | #ifdef G4VERBOSE |
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| 140 | if (GetVerboseLevel()>1) { |
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| 141 | G4cout << "G4PhaseSpaceDecayChannel::OneBodyDecayIt "; |
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| 142 | G4cout << " create decay products in rest frame " <<G4endl; |
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| 143 | products->DumpInfo(); |
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| 144 | } |
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| 145 | #endif |
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| 146 | return products; |
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| 147 | } |
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| 148 | |
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| 149 | G4DecayProducts *G4PhaseSpaceDecayChannel::TwoBodyDecayIt() |
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| 150 | { |
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| 151 | #ifdef G4VERBOSE |
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| 152 | if (GetVerboseLevel()>1) G4cout << "G4PhaseSpaceDecayChannel::TwoBodyDecayIt()"<<G4endl; |
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| 153 | #endif |
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| 154 | // parent mass |
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| 155 | G4double parentmass = parent_mass; |
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| 156 | |
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| 157 | //daughters'mass |
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| 158 | G4double daughtermass[2]; |
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| 159 | G4double daughtermomentum; |
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| 160 | daughtermass[0] = daughters_mass[0]; |
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| 161 | daughtermass[1] = daughters_mass[1]; |
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| 162 | |
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| 163 | //create parent G4DynamicParticle at rest |
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| 164 | G4ThreeVector dummy; |
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| 165 | G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0); |
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| 166 | //create G4Decayproducts |
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| 167 | G4DecayProducts *products = new G4DecayProducts(*parentparticle); |
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| 168 | delete parentparticle; |
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| 169 | |
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| 170 | //calculate daughter momentum |
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| 171 | daughtermomentum = Pmx(parentmass,daughtermass[0],daughtermass[1]); |
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| 172 | if (daughtermomentum <0.0) { |
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| 173 | #ifdef G4VERBOSE |
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| 174 | if (GetVerboseLevel()>0) { |
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| 175 | G4cerr << "G4PhaseSpaceDecayChannel::TwoBodyDecayIt " |
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| 176 | << "sum of daughter mass is larger than parent mass" << G4endl; |
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| 177 | G4cerr << "parent :" << parent->GetParticleName() << " " << parent_mass/GeV << G4endl; |
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| 178 | G4cerr << "daughter 1 :" << daughters[0]->GetParticleName() << " " << daughtermass[0]/GeV << G4endl; |
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| 179 | G4cerr << "daughter 2:" << daughters[1]->GetParticleName() << " " << daughtermass[1]/GeV << G4endl; |
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| 180 | } |
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| 181 | #endif |
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| 182 | G4Exception("G4PhaseSpaceDecayChannel::TwoBodyDecayIt", |
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| 183 | "can not create decay products", JustWarning, |
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| 184 | "sum of daughter mass is larger than parent mass"); |
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| 185 | return products; |
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| 186 | } |
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| 187 | |
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| 188 | G4double costheta = 2.*G4UniformRand()-1.0; |
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| 189 | G4double sintheta = std::sqrt((1.0 - costheta)*(1.0 + costheta)); |
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| 190 | G4double phi = twopi*G4UniformRand()*rad; |
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| 191 | G4ThreeVector direction(sintheta*std::cos(phi),sintheta*std::sin(phi),costheta); |
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| 192 | |
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| 193 | //create daughter G4DynamicParticle |
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| 194 | G4DynamicParticle * daughterparticle = new G4DynamicParticle( daughters[0], direction*daughtermomentum); |
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| 195 | products->PushProducts(daughterparticle); |
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| 196 | daughterparticle = new G4DynamicParticle( daughters[1], direction*(-1.0*daughtermomentum)); |
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| 197 | products->PushProducts(daughterparticle); |
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| 198 | |
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| 199 | #ifdef G4VERBOSE |
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| 200 | if (GetVerboseLevel()>1) { |
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| 201 | G4cout << "G4PhaseSpaceDecayChannel::TwoBodyDecayIt "; |
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| 202 | G4cout << " create decay products in rest frame " <<G4endl; |
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| 203 | products->DumpInfo(); |
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| 204 | } |
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| 205 | #endif |
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| 206 | return products; |
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| 207 | } |
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| 208 | |
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| 209 | G4DecayProducts *G4PhaseSpaceDecayChannel::ThreeBodyDecayIt() |
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| 210 | // algorism of this code is originally written in GDECA3 of GEANT3 |
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| 211 | { |
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| 212 | #ifdef G4VERBOSE |
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| 213 | if (GetVerboseLevel()>1) G4cout << "G4PhaseSpaceDecayChannel::ThreeBodyDecayIt()"<<G4endl; |
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| 214 | #endif |
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| 215 | // parent mass |
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| 216 | G4double parentmass = parent_mass; |
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| 217 | //daughters'mass |
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| 218 | G4double daughtermass[3]; |
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| 219 | G4double sumofdaughtermass = 0.0; |
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| 220 | for (G4int index=0; index<3; index++){ |
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| 221 | daughtermass[index] = daughters_mass[index]; |
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| 222 | sumofdaughtermass += daughtermass[index]; |
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| 223 | } |
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| 224 | |
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| 225 | //create parent G4DynamicParticle at rest |
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| 226 | G4ThreeVector dummy; |
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| 227 | G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0); |
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| 228 | |
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| 229 | |
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| 230 | //create G4Decayproducts |
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| 231 | G4DecayProducts *products = new G4DecayProducts(*parentparticle); |
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| 232 | delete parentparticle; |
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| 233 | |
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| 234 | if (sumofdaughtermass >parentmass) { |
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| 235 | #ifdef G4VERBOSE |
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| 236 | if (GetVerboseLevel()>0) { |
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| 237 | G4cerr << "G4PhaseSpaceDecayChannel::ThreeBodyDecayIt " |
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| 238 | << "sum of daughter mass is larger than parent mass" << G4endl; |
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| 239 | G4cerr << "parent :" << parent->GetParticleName() << " " << parent_mass/GeV << G4endl; |
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| 240 | G4cerr << "daughter 1 :" << daughters[0]->GetParticleName() << " " << daughtermass[0]/GeV << G4endl; |
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| 241 | G4cerr << "daughter 2:" << daughters[1]->GetParticleName() << " " << daughtermass[1]/GeV << G4endl; |
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| 242 | G4cerr << "daughter 3:" << daughters[2]->GetParticleName() << " " << daughtermass[2]/GeV << G4endl; |
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| 243 | } |
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| 244 | #endif |
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| 245 | G4Exception("G4PhaseSpaceDecayChannel::ThreeBodyDecayIt", |
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| 246 | "can not create decay products", JustWarning, |
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| 247 | "sum of daughter mass is larger than parent mass"); |
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| 248 | return products; |
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| 249 | } |
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| 250 | |
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| 251 | |
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| 252 | |
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| 253 | //calculate daughter momentum |
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| 254 | // Generate two |
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| 255 | G4double rd1, rd2, rd; |
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| 256 | G4double daughtermomentum[3]; |
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| 257 | G4double momentummax=0.0, momentumsum = 0.0; |
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| 258 | G4double energy; |
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| 259 | |
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| 260 | do { |
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| 261 | rd1 = G4UniformRand(); |
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| 262 | rd2 = G4UniformRand(); |
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| 263 | if (rd2 > rd1) { |
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| 264 | rd = rd1; |
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| 265 | rd1 = rd2; |
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| 266 | rd2 = rd; |
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| 267 | } |
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| 268 | momentummax = 0.0; |
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| 269 | momentumsum = 0.0; |
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| 270 | // daughter 0 |
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| 271 | energy = rd2*(parentmass - sumofdaughtermass); |
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| 272 | daughtermomentum[0] = std::sqrt(energy*energy + 2.0*energy* daughtermass[0]); |
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| 273 | if ( daughtermomentum[0] >momentummax )momentummax = daughtermomentum[0]; |
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| 274 | momentumsum += daughtermomentum[0]; |
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| 275 | // daughter 1 |
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| 276 | energy = (1.-rd1)*(parentmass - sumofdaughtermass); |
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| 277 | daughtermomentum[1] = std::sqrt(energy*energy + 2.0*energy* daughtermass[1]); |
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| 278 | if ( daughtermomentum[1] >momentummax )momentummax = daughtermomentum[1]; |
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| 279 | momentumsum += daughtermomentum[1]; |
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| 280 | // daughter 2 |
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| 281 | energy = (rd1-rd2)*(parentmass - sumofdaughtermass); |
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| 282 | daughtermomentum[2] = std::sqrt(energy*energy + 2.0*energy* daughtermass[2]); |
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| 283 | if ( daughtermomentum[2] >momentummax )momentummax = daughtermomentum[2]; |
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| 284 | momentumsum += daughtermomentum[2]; |
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| 285 | } while (momentummax > momentumsum - momentummax ); |
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| 286 | // output message |
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| 287 | #ifdef G4VERBOSE |
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| 288 | if (GetVerboseLevel()>1) { |
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| 289 | G4cout << " daughter 0:" << daughtermomentum[0]/GeV << "[GeV/c]" <<G4endl; |
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| 290 | G4cout << " daughter 1:" << daughtermomentum[1]/GeV << "[GeV/c]" <<G4endl; |
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| 291 | G4cout << " daughter 2:" << daughtermomentum[2]/GeV << "[GeV/c]" <<G4endl; |
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| 292 | G4cout << " momentum sum:" << momentumsum/GeV << "[GeV/c]" <<G4endl; |
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| 293 | } |
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| 294 | #endif |
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| 295 | |
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| 296 | //create daughter G4DynamicParticle |
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| 297 | G4double costheta, sintheta, phi, sinphi, cosphi; |
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| 298 | G4double costhetan, sinthetan, phin, sinphin, cosphin; |
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| 299 | costheta = 2.*G4UniformRand()-1.0; |
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| 300 | sintheta = std::sqrt((1.0-costheta)*(1.0+costheta)); |
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| 301 | phi = twopi*G4UniformRand()*rad; |
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| 302 | sinphi = std::sin(phi); |
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| 303 | cosphi = std::cos(phi); |
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| 304 | G4ThreeVector direction0(sintheta*cosphi,sintheta*sinphi,costheta); |
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| 305 | G4DynamicParticle * daughterparticle |
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| 306 | = new G4DynamicParticle( daughters[0], direction0*daughtermomentum[0]); |
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| 307 | products->PushProducts(daughterparticle); |
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| 308 | |
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| 309 | costhetan = (daughtermomentum[1]*daughtermomentum[1]-daughtermomentum[2]*daughtermomentum[2]-daughtermomentum[0]*daughtermomentum[0])/(2.0*daughtermomentum[2]*daughtermomentum[0]); |
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| 310 | sinthetan = std::sqrt((1.0-costhetan)*(1.0+costhetan)); |
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| 311 | phin = twopi*G4UniformRand()*rad; |
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| 312 | sinphin = std::sin(phin); |
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| 313 | cosphin = std::cos(phin); |
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| 314 | G4ThreeVector direction2; |
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| 315 | direction2.setX( sinthetan*cosphin*costheta*cosphi - sinthetan*sinphin*sinphi + costhetan*sintheta*cosphi); |
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| 316 | direction2.setY( sinthetan*cosphin*costheta*sinphi + sinthetan*sinphin*cosphi + costhetan*sintheta*sinphi); |
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| 317 | direction2.setZ( -sinthetan*cosphin*sintheta + costhetan*costheta); |
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| 318 | daughterparticle = new G4DynamicParticle( daughters[2], direction2*(daughtermomentum[2]/direction2.mag())); |
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| 319 | products->PushProducts(daughterparticle); |
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| 320 | |
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| 321 | daughterparticle = |
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| 322 | new G4DynamicParticle( |
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| 323 | daughters[1], |
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| 324 | (direction0*daughtermomentum[0] + direction2*(daughtermomentum[2]/direction2.mag()))*(-1.0) |
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| 325 | ); |
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| 326 | products->PushProducts(daughterparticle); |
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| 327 | |
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| 328 | #ifdef G4VERBOSE |
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| 329 | if (GetVerboseLevel()>1) { |
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| 330 | G4cout << "G4PhaseSpaceDecayChannel::ThreeBodyDecayIt "; |
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| 331 | G4cout << " create decay products in rest frame " <<G4endl; |
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| 332 | products->DumpInfo(); |
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| 333 | } |
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| 334 | #endif |
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| 335 | return products; |
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| 336 | } |
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| 337 | |
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| 338 | G4DecayProducts *G4PhaseSpaceDecayChannel::ManyBodyDecayIt() |
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| 339 | // algorithm of this code is originally written in FORTRAN by M.Asai |
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| 340 | //****************************************************************** |
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| 341 | // NBODY |
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| 342 | // N-body phase space Monte-Carlo generator |
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| 343 | // Makoto Asai |
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| 344 | // Hiroshima Institute of Technology |
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| 345 | // (asai@kekvax.kek.jp) |
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| 346 | // Revised release : 19/Apr/1995 |
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| 347 | // |
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| 348 | { |
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| 349 | G4int index, index2; |
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| 350 | |
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| 351 | //return value |
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| 352 | G4DecayProducts *products; |
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| 353 | |
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| 354 | #ifdef G4VERBOSE |
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| 355 | if (GetVerboseLevel()>1) G4cout << "G4PhaseSpaceDecayChannel::ManyBodyDecayIt()"<<G4endl; |
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| 356 | #endif |
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| 357 | // parent mass |
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| 358 | G4double parentmass = parent_mass; |
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| 359 | //daughters'mass |
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| 360 | G4double *daughtermass = new G4double[numberOfDaughters]; |
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| 361 | G4double sumofdaughtermass = 0.0; |
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| 362 | for (index=0; index<numberOfDaughters; index++){ |
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| 363 | daughtermass[index] = daughters_mass[index]; |
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| 364 | sumofdaughtermass += daughtermass[index]; |
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| 365 | } |
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| 366 | |
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| 367 | //Calculate daughter momentum |
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| 368 | G4double *daughtermomentum = new G4double[numberOfDaughters]; |
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| 369 | G4ThreeVector direction; |
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| 370 | G4DynamicParticle **daughterparticle; |
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| 371 | G4double *sm = new G4double[numberOfDaughters]; |
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| 372 | G4double tmas; |
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| 373 | G4double weight = 1.0; |
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| 374 | G4int numberOfTry = 0; |
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| 375 | |
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| 376 | do { |
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| 377 | //Generate rundom number in descending order |
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| 378 | G4double temp; |
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| 379 | G4double *rd = new G4double[numberOfDaughters]; |
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| 380 | rd[0] = 1.0; |
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| 381 | for(index =1; index < numberOfDaughters -1; index++) rd[index] = G4UniformRand(); |
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| 382 | rd[ numberOfDaughters -1] = 0.0; |
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| 383 | for(index =1; index < numberOfDaughters -1; index++) { |
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| 384 | for(index2 = index+1; index2 < numberOfDaughters; index2++) { |
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| 385 | if (rd[index] < rd[index2]){ |
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| 386 | temp = rd[index]; |
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| 387 | rd[index] = rd[index2]; |
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| 388 | rd[index2] = temp; |
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| 389 | } |
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| 390 | } |
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| 391 | } |
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| 392 | |
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| 393 | //calcurate virtual mass |
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| 394 | tmas = parentmass - sumofdaughtermass; |
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| 395 | temp = sumofdaughtermass; |
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| 396 | for(index =0; index < numberOfDaughters; index++) { |
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| 397 | sm[index] = rd[index]*tmas + temp; |
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| 398 | temp -= daughtermass[index]; |
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| 399 | if (GetVerboseLevel()>1) { |
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| 400 | G4cout << index << " rundom number:" << rd[index]; |
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| 401 | G4cout << " virtual mass:" << sm[index]/GeV << "[GeV/c/c]" <<G4endl; |
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| 402 | } |
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| 403 | } |
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| 404 | delete [] rd; |
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| 405 | |
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| 406 | //Calculate daughter momentum |
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| 407 | weight = 1.0; |
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| 408 | index =numberOfDaughters-1; |
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| 409 | daughtermomentum[index]= Pmx( sm[index-1],daughtermass[index-1], sm[index]); |
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| 410 | #ifdef G4VERBOSE |
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| 411 | if (GetVerboseLevel()>1) { |
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| 412 | G4cout << " daughter " << index << ":" << *daughters_name[index]; |
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| 413 | G4cout << " momentum:" << daughtermomentum[index]/GeV << "[GeV/c]" <<G4endl; |
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| 414 | } |
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| 415 | #endif |
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| 416 | for(index =numberOfDaughters-2; index>=0; index--) { |
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| 417 | // calculate |
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| 418 | daughtermomentum[index]= Pmx( sm[index],daughtermass[index], sm[index +1]); |
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| 419 | if(daughtermomentum[index] < 0.0) { |
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| 420 | // !!! illegal momentum !!! |
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| 421 | #ifdef G4VERBOSE |
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| 422 | if (GetVerboseLevel()>0) { |
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| 423 | G4cout << "G4PhaseSpaceDecayChannel::ManyBodyDecayIt "; |
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| 424 | G4cout << " can not calculate daughter momentum " <<G4endl; |
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| 425 | G4cout << " parent:" << *parent_name; |
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| 426 | G4cout << " mass:" << parentmass/GeV << "[GeV/c/c]" <<G4endl; |
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| 427 | G4cout << " daughter " << index << ":" << *daughters_name[index]; |
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| 428 | G4cout << " mass:" << daughtermass[index]/GeV << "[GeV/c/c]" ; |
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| 429 | G4cout << " mass:" << daughtermomentum[index]/GeV << "[GeV/c]" <<G4endl; |
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| 430 | } |
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| 431 | #endif |
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| 432 | delete [] sm; |
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| 433 | delete [] daughtermass; |
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| 434 | delete [] daughtermomentum; |
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| 435 | |
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| 436 | G4Exception("G4PhaseSpaceDecayChannel::ManyBodyDecayIt", |
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| 437 | "can not create decay products", JustWarning, |
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| 438 | "sum of daughter mass is larger than parent mass"); |
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| 439 | |
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| 440 | return 0; // Error detection |
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| 441 | |
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| 442 | } else { |
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| 443 | // calculate weight of this events |
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| 444 | weight *= daughtermomentum[index]/sm[index]; |
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| 445 | #ifdef G4VERBOSE |
---|
| 446 | if (GetVerboseLevel()>1) { |
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| 447 | G4cout << " daughter " << index << ":" << *daughters_name[index]; |
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| 448 | G4cout << " momentum:" << daughtermomentum[index]/GeV << "[GeV/c]" <<G4endl; |
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| 449 | } |
---|
| 450 | #endif |
---|
| 451 | } |
---|
| 452 | } |
---|
| 453 | |
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| 454 | #ifdef G4VERBOSE |
---|
| 455 | if (GetVerboseLevel()>1) { |
---|
| 456 | G4cout << " weight: " << weight <<G4endl; |
---|
| 457 | } |
---|
| 458 | #endif |
---|
| 459 | |
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| 460 | // exit if number of Try exceeds 100 |
---|
| 461 | if (numberOfTry++ >100) { |
---|
| 462 | #ifdef G4VERBOSE |
---|
| 463 | if (GetVerboseLevel()>0) { |
---|
| 464 | G4cout << "G4PhaseSpaceDecayChannel::ManyBodyDecayIt: "; |
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| 465 | G4cout << " can not determine Decay Kinematics " << G4endl; |
---|
| 466 | G4cout << "parent : " << *parent_name << G4endl; |
---|
| 467 | G4cout << "daughters : "; |
---|
| 468 | for(index=0; index<numberOfDaughters; index++) { |
---|
| 469 | G4cout << *daughters_name[index] << " , "; |
---|
| 470 | } |
---|
| 471 | G4cout << G4endl; |
---|
| 472 | } |
---|
| 473 | #endif |
---|
| 474 | G4Exception("G4PhaseSpaceDecayChannel::ManyBodyDecayIt: ", |
---|
| 475 | " Cannot decay ", JustWarning, |
---|
| 476 | " Decay Kinematics cannot be calculated "); |
---|
| 477 | |
---|
| 478 | delete [] sm; |
---|
| 479 | delete [] daughtermass; |
---|
| 480 | delete [] daughtermomentum; |
---|
| 481 | return 0; // Error detection |
---|
| 482 | } |
---|
| 483 | } while ( weight > G4UniformRand()); |
---|
| 484 | |
---|
| 485 | #ifdef G4VERBOSE |
---|
| 486 | if (GetVerboseLevel()>1) { |
---|
| 487 | G4cout << "Start calulation of daughters momentum vector "<<G4endl; |
---|
| 488 | } |
---|
| 489 | #endif |
---|
| 490 | |
---|
| 491 | G4double costheta, sintheta, phi; |
---|
| 492 | G4double beta; |
---|
| 493 | daughterparticle = new G4DynamicParticle*[numberOfDaughters]; |
---|
| 494 | |
---|
| 495 | index = numberOfDaughters -2; |
---|
| 496 | costheta = 2.*G4UniformRand()-1.0; |
---|
| 497 | sintheta = std::sqrt((1.0-costheta)*(1.0+costheta)); |
---|
| 498 | phi = twopi*G4UniformRand()*rad; |
---|
| 499 | direction.setZ(costheta); |
---|
| 500 | direction.setY(sintheta*std::sin(phi)); |
---|
| 501 | direction.setX(sintheta*std::cos(phi)); |
---|
| 502 | daughterparticle[index] = new G4DynamicParticle( daughters[index], direction*daughtermomentum[index] ); |
---|
| 503 | daughterparticle[index+1] = new G4DynamicParticle( daughters[index+1], direction*(-1.0*daughtermomentum[index]) ); |
---|
| 504 | |
---|
| 505 | for (index = numberOfDaughters -3; index >= 0; index--) { |
---|
| 506 | //calculate momentum direction |
---|
| 507 | costheta = 2.*G4UniformRand()-1.0; |
---|
| 508 | sintheta = std::sqrt((1.0-costheta)*(1.0+costheta)); |
---|
| 509 | phi = twopi*G4UniformRand()*rad; |
---|
| 510 | direction.setZ(costheta); |
---|
| 511 | direction.setY(sintheta*std::sin(phi)); |
---|
| 512 | direction.setX(sintheta*std::cos(phi)); |
---|
| 513 | |
---|
| 514 | // boost already created particles |
---|
| 515 | beta = daughtermomentum[index]; |
---|
| 516 | beta /= std::sqrt( daughtermomentum[index]*daughtermomentum[index] + sm[index+1]*sm[index+1] ); |
---|
| 517 | for (G4int index2 = index+1; index2<numberOfDaughters; index2++) { |
---|
| 518 | G4LorentzVector p4; |
---|
| 519 | // make G4LorentzVector for secondaries |
---|
| 520 | p4 = daughterparticle[index2]->Get4Momentum(); |
---|
| 521 | |
---|
| 522 | // boost secondaries to new frame |
---|
| 523 | p4.boost( direction.x()*beta, direction.y()*beta, direction.z()*beta); |
---|
| 524 | |
---|
| 525 | // change energy/momentum |
---|
| 526 | daughterparticle[index2]->Set4Momentum(p4); |
---|
| 527 | } |
---|
| 528 | //create daughter G4DynamicParticle |
---|
| 529 | daughterparticle[index]= new G4DynamicParticle( daughters[index], direction*(-1.0*daughtermomentum[index])); |
---|
| 530 | } |
---|
| 531 | |
---|
| 532 | //create G4Decayproducts |
---|
| 533 | G4DynamicParticle *parentparticle; |
---|
| 534 | direction.setX(1.0); direction.setY(0.0); direction.setZ(0.0); |
---|
| 535 | parentparticle = new G4DynamicParticle( parent, direction, 0.0); |
---|
| 536 | products = new G4DecayProducts(*parentparticle); |
---|
| 537 | delete parentparticle; |
---|
| 538 | for (index = 0; index<numberOfDaughters; index++) { |
---|
| 539 | products->PushProducts(daughterparticle[index]); |
---|
| 540 | } |
---|
| 541 | |
---|
| 542 | #ifdef G4VERBOSE |
---|
| 543 | if (GetVerboseLevel()>1) { |
---|
| 544 | G4cout << "G4PhaseSpaceDecayChannel::ManyBodyDecayIt "; |
---|
| 545 | G4cout << " create decay products in rest frame " << G4endl; |
---|
| 546 | products->DumpInfo(); |
---|
| 547 | } |
---|
| 548 | #endif |
---|
| 549 | |
---|
| 550 | delete [] daughterparticle; |
---|
| 551 | delete [] daughtermomentum; |
---|
| 552 | delete [] daughtermass; |
---|
| 553 | delete [] sm; |
---|
| 554 | |
---|
| 555 | return products; |
---|
| 556 | } |
---|
| 557 | |
---|
| 558 | |
---|
| 559 | G4double G4PhaseSpaceDecayChannel::Pmx(G4double e, G4double p1, G4double p2) |
---|
| 560 | { |
---|
| 561 | // calcurate momentum of daughter particles in two-body decay |
---|
| 562 | G4double ppp = (e+p1+p2)*(e+p1-p2)*(e-p1+p2)*(e-p1-p2)/(4.0*e*e); |
---|
| 563 | if (ppp>0) return std::sqrt(ppp); |
---|
| 564 | else return -1.; |
---|
| 565 | } |
---|
| 566 | |
---|
| 567 | |
---|
| 568 | |
---|