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 | // $Id: G4QCaptureAtRest.hh,v 1.2 2010/06/25 09:46:01 gunter Exp $ |
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27 | // GEANT4 tag $Name: hadr-chips-V09-03-08 $ |
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28 | // |
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29 | // ---------------- G4QCaptureAtRest header ---------------- |
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30 | // by Mikhail Kossov, December 2003. |
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31 | // Header of G4QCaptureAtRest class of the CHIPS Simulation Branch in GEANT4 |
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32 | // ------------------------------------------------------------------------------- |
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33 | // At present (May 2009) only pi-, K- and antiNucleon capture are tested, which |
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34 | // are the most crucial for the in matter simulation. The hyperon capture (Sigma-, |
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35 | // Xi-, Omega-, antiSigma+) is implemented, but not tested and it is not clear how |
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36 | // frequently this kind of interaction takes place in the simulation of the hadronic |
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37 | // showers. The antiNeutron Capture At Rest is implemented by this G4QCaptureAtRest |
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38 | // class, but it is not clear how the anti-neutrons are stopped in Geant4 tracking. |
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39 | // It can be stopped only by interactions with electrons, as the annihilation cross |
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40 | // section is huge and any interaction with nucleus results in annihilation. The |
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41 | // mu- & tau- Capture At Rest (mu-,nu) & (mu-,nu) are weak processes, which must |
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42 | // be simulated together with the reversed Betha decay (e-,nu). While mu- capture is |
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43 | // similar to the pi- capture from the nuclear fragmentation point of view (the energy |
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44 | // scale is shrinked because m_mu < m_pi and a part of the energy is lost because of |
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45 | // the neutrino radiation), the time scale of the mu- capture process is not exact, |
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46 | // but it is clear, that it is well delayed. By this reason the mu- capture can be |
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47 | // excluded from the G4QCaptureAtRest and can be implemented in the "LongLivingDecay" |
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48 | // branch of simulation, which includes excited states of nuclei and short living |
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49 | // isotopes. On the "Fast Simulation" Level all radioactive isotopes, long living |
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50 | // nuclear excitations, mu-atoms etc, which can be important for the background |
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51 | // signals, must be collected in the continuous database and simulated separately. |
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52 | // CHIPS is SU(3) event generator, so it does not include reactions with the heavy |
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53 | // (c,b,t) quarks involved such as antiDs-, which can be simulated only by SU(6) |
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54 | // QUIPS (QUark Invariant Phase Space) model. - May 2009, M.Kossov.- |
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55 | // ------------------------------------------------------------------------------- |
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56 | // All algorithms are similar: the captured particle is absorbed by a nuclear cluster |
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57 | // with the subsequent Quark Exchange nuclear fragmentation. The Anti-Proton (antiSigma+) |
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58 | // Capture algorithm is more complicated: the anti-baryon annihilates with the quasyfree |
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59 | // nucleons on the nuclear periphery. The peripheral interaction results in a number |
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60 | // of mesons. A part of them misses the nucleus and comes directly to the output, |
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61 | // while others create Multy Quasmon Excitation in the nucleus with the subsequent |
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62 | // Quark Excange Fragmentation of the nucleus. At present the two step mechanism of |
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63 | // the antiProton-Nucleus interaction is hardwired in the G4QEnvironment class, but |
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64 | // with time the first step of the interaction can be moved to this G4QCaptureAtRest |
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65 | // class, to make the G4QEnvirement class simpler and better defined. This is |
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66 | // necessary because the G4QEnvironment class is going to loos the previlage of |
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67 | // the CHIPS Head Class (as previously the G4Quasmon class lost it) and G4QCollision |
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68 | // class is going to be the CHIPS Head Class, where a few Nuclear Environments can |
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69 | // exist (e.g. the Nuclear Environment of the Projectile Nucleus and the Nuclear |
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70 | // Environment of the Target Nucleus). By the way, the antiProton-H1 interaction At |
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71 | // Rest (CHIPSI) can be still simulated with only the G4Quasmon class, as this |
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72 | // reaction does not have any nuclear environment.- May 2009, Mikhail Kossov.- |
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73 | // -------------------------------------------------------------------------------- |
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74 | // **************************************************************************************** |
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75 | // This Header is a part of the CHIPS physics package (author: M. Kosov) |
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76 | // **************************************************************************************** |
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77 | // Short Description: This is a universal process for nuclear capture |
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78 | // (including annihilation) of all negative particles (cold neutrons, negative |
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79 | // hadrons, negative leptons: mu- & tau-). It can be used for the cold neutron |
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80 | // capture, but somebody should decide what is the probability (defined |
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81 | // by the capture cross-section and atomic material properties) to switch |
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82 | // the cold neutron to the at-rest neutron. - M.K. 2009. |
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83 | // ---------------------------------------------------------------------- |
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84 | |
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85 | #ifndef G4QCaptureAtRest_hh |
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86 | #define G4QCaptureAtRest_hh |
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87 | |
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88 | // GEANT4 Headers |
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89 | #include "globals.hh" |
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90 | #include "G4ios.hh" |
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91 | #include "G4VRestProcess.hh" |
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92 | #include "G4ParticleTypes.hh" |
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93 | #include "G4VParticleChange.hh" |
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94 | #include "G4ParticleDefinition.hh" |
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95 | #include "G4DynamicParticle.hh" |
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96 | #include "Randomize.hh" |
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97 | #include "G4ThreeVector.hh" |
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98 | #include "G4LorentzVector.hh" |
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99 | #include "G4RandomDirection.hh" |
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100 | |
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101 | // CHIPS Headers |
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102 | #include "G4QEnvironment.hh" |
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103 | #include "G4QIsotope.hh" |
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104 | #include "G4QPDGToG4Particle.hh" |
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105 | |
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106 | class G4QCaptureAtRest : public G4VRestProcess |
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107 | { |
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108 | private: |
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109 | |
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110 | // Hide assignment operator as private |
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111 | G4QCaptureAtRest& operator=(const G4QCaptureAtRest &right); |
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112 | |
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113 | // Copy constructor |
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114 | G4QCaptureAtRest(const G4QCaptureAtRest& ); |
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115 | |
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116 | public: |
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117 | |
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118 | // Constructor |
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119 | G4QCaptureAtRest(const G4String& processName ="CHIPSNuclearCaptureAtRest"); |
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120 | |
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121 | // Destructor |
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122 | virtual ~G4QCaptureAtRest(); |
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123 | |
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124 | virtual G4bool IsApplicable(const G4ParticleDefinition& particle); |
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125 | |
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126 | G4VParticleChange* AtRestDoIt(const G4Track& aTrack, const G4Step& aStep); |
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127 | |
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128 | G4LorentzVector GetEnegryMomentumConservation(); |
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129 | |
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130 | G4int GetNumberOfNeutronsInTarget(); |
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131 | |
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132 | // Static functions |
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133 | static void SetManual(); |
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134 | static void SetStandard(); |
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135 | static void SetParameters(G4double temper=180., G4double ssin2g=.1, G4double etaetap=.3, |
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136 | G4double fN=0., G4double fD=0., G4double cP=1., G4double mR=1., |
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137 | G4int npCHIPSWorld=234, G4double solAn=.5, G4bool efFlag=false, |
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138 | G4double piTh=141.4,G4double mpi2=20000.,G4double dinum=1880.); |
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139 | |
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140 | protected: |
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141 | |
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142 | // zero mean lifetime |
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143 | G4double GetMeanLifeTime(const G4Track& aTrack, G4ForceCondition* ); |
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144 | G4double RandomizeDecayElectron(G4int Z); // Randomize energy of decay electron (in MeV) |
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145 | private: |
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146 | |
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147 | G4bool RandomizeMuDecayOrCapture(G4int Z, G4int N); // true=MuCapture, false=MuDecay |
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148 | void CalculateEnergyDepositionOfMuCapture(G4int Z); // (2p->1s, MeV) @@ Now N-independent |
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149 | G4bool RandomizeTauDecayOrCapture(G4int Z, G4int N);// true=TauCapture, false=TauDecay |
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150 | void CalculateEnergyDepositionOfTauCapture(G4int Z);// (2p->1s, MeV) @@N-independ,Improve |
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151 | |
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152 | // BODY |
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153 | private: |
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154 | // Static Parameters |
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155 | static G4bool manualFlag; // If false then standard parameters are used |
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156 | static G4int nPartCWorld; // The#of particles for hadronization (limit of A of fragm.) |
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157 | // -> Parameters of the G4Quasmon class: |
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158 | static G4double Temperature; // Quasmon Temperature |
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159 | static G4double SSin2Gluons; // Percent of ssbar sea in a constituen gluon |
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160 | static G4double EtaEtaprime; // Part of eta-prime in all etas |
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161 | // -> Parameters of the G4QNucleus class: |
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162 | static G4double freeNuc; // probability of the quasi-free baryon on surface |
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163 | static G4double freeDib; // probability of the quasi-free dibaryon on surface |
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164 | static G4double clustProb; // clusterization probability in dense region |
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165 | static G4double mediRatio; // relative vacuum hadronization probability |
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166 | // -> Parameters of the G4QEnvironment class: |
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167 | static G4bool EnergyFlux; // Flag for Energy Flux use instead of Multy Quasmon |
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168 | static G4double SolidAngle; // Part of Solid Angle to capture secondaries(@@A-dep) |
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169 | static G4double PiPrThresh; // Pion Production Threshold for gammas |
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170 | static G4double M2ShiftVir; // Shift for M2=-Q2=m_pi^2 of the virtual gamma |
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171 | static G4double DiNuclMass; // Double Nucleon Mass for virtual normalization |
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172 | // |
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173 | // Working parameters |
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174 | G4LorentzVector EnMomConservation; // Residual of Energy/Momentum Cons. |
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175 | G4int nOfNeutrons; // #of neutrons in the target nucleus |
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176 | // Modifires for the reaction |
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177 | G4double Time; // Time shift of the capture reaction |
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178 | G4double EnergyDeposition; // Energy deposited in the reaction |
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179 | |
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180 | }; |
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181 | #endif |
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