include/Geant4/G4INCLPhaseSpaceRauboldLynch.hh

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0025 //
0026 // INCL++ intra-nuclear cascade model
0027 // Alain Boudard, CEA-Saclay, France
0028 // Joseph Cugnon, University of Liege, Belgium
0029 // Jean-Christophe David, CEA-Saclay, France
0030 // Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
0031 // Sylvie Leray, CEA-Saclay, France
0032 // Davide Mancusi, CEA-Saclay, France
0033 //
0034 #define INCLXX_IN_GEANT4_MODE 1
0035
0036 #include "globals.hh"
0037
0038 #ifndef G4INCLPHASESPACERAUBOLDLYNCH_HH
0039 #define G4INCLPHASESPACERAUBOLDLYNCH_HH
0040
0041 #include "G4INCLThreeVector.hh"
0042 #include "G4INCLParticle.hh"
0043 #include "G4INCLIPhaseSpaceGenerator.hh"
0044 #include "G4INCLInterpolationTable.hh"
0045 #include <vector>
0046
0047 namespace G4INCL {
0048   /// \brief Generate momenta using the RauboldLynch method
0049   class PhaseSpaceRauboldLynch : public IPhaseSpaceGenerator {
0050
0051     public:
0052       PhaseSpaceRauboldLynch();
0053       virtual ~PhaseSpaceRauboldLynch();
0054
0055       /// \brief Dummy copy constructor to silence Coverity warning
0056       PhaseSpaceRauboldLynch(PhaseSpaceRauboldLynch const &other);
0057
0058       /// \brief Dummy assignment operator to silence Coverity warning
0059       PhaseSpaceRauboldLynch &operator=(PhaseSpaceRauboldLynch const &rhs);
0060
0061       /** \brief Generate momenta according to a uniform, Lorentz-invariant phase-space model
0062        *
0063        * This function will assign momenta to the particles in the list that is
0064        * passed as an argument. The event is generated in the CM frame.
0065        *
0066        * \param sqrtS total centre-of-mass energy of the system
0067        * \param particles list of particles
0068        */
0069       void generate(const G4double sqrtS, ParticleList &particles);
0070
0071       /// \brief Return the largest generated weight
0072       G4double getMaxGeneratedWeight() const;
0073
0074     private:
0075       std::vector<G4double> masses;
0076       std::vector<G4double> sumMasses;
0077       std::vector<G4double> rnd;
0078       std::vector<G4double> invariantMasses;
0079       std::vector<G4double> momentaCM;
0080       size_t nParticles;
0081       G4double sqrtS;
0082       G4double availableEnergy;
0083       G4double maxGeneratedWeight;
0084
0085       static const size_t nMasslessParticlesTable = 13;
0086       static const size_t wMaxNE = 30;
0087       static const G4double wMaxMasslessX[wMaxNE];
0088       static const G4double wMaxMasslessY[wMaxNE];
0089       static const G4double wMaxCorrectionX[wMaxNE];
0090       static const G4double wMaxCorrectionY[wMaxNE];
0091       static const G4double wMaxInterpolationMargin;
0092
0093       InterpolationTable *wMaxMassless;
0094       InterpolationTable *wMaxCorrection;
0095
0096       static const size_t wMaxNP = 20;
0097
0098       /// \brief Precalculated coefficients: -ln(n)
0099       G4double prelog[wMaxNP];
0100
0101       /// \brief Initialize internal structures (masses and sum of masses)
0102       void initialize(ParticleList &particles);
0103
0104       /// \brief Compute the maximum possible weight using a naive algorithm
0105       G4double computeMaximumWeightNaive();
0106
0107       /// \brief Compute the maximum possible weight using parametrizations
0108       G4double computeMaximumWeightParam();
0109
0110       /// \brief Compute the maximum possible weight
0111       G4double computeWeight();
0112
0113       /// \brief Generate an event
0114       void generateEvent(ParticleList &particles);
0115   };
0116 }
0117
0118 #endif // G4INCLPHASESPACERAUBOLDLYNCH_HH