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// -------------------------------------------------------------------
//
// GEANT4 Class header file
//
//
// File name:     G4eplusTo3GammaOKVIModel
//
// Authors:  Andrei Alkin, Vladimir Ivanchenko, Omrame Kadri
//
// Creation date: 29.03.2018
//
//
// Class Description:
//
// Implementation of e+ annihilation into 3 gamma on fly
//
// V.N.Baier, V.S. Fadin, V.A. Khose, E.A. Kuraev,
// Physics Reports 78 (1981) 293-393.
// 
// -------------------------------------------------------------------
//

#ifndef G4eplusTo3GammaOKVIModel_h
#define G4eplusTo3GammaOKVIModel_h 1

#include "G4VEmModel.hh"

class G4ParticleChangeForGamma;

class G4eplusTo3GammaOKVIModel : public G4VEmModel
{

public:

  explicit G4eplusTo3GammaOKVIModel(const G4ParticleDefinition* p = nullptr,
                                    const G4String& nam = "eplus3ggOKVI");

  ~G4eplusTo3GammaOKVIModel() override;

  void Initialise(const G4ParticleDefinition*, const G4DataVector&) override;

  G4double ComputeCrossSectionPerElectron(G4double kinEnergy);
  
  G4double ComputeCrossSectionPerAtom(
                                 const G4ParticleDefinition*,
                                       G4double kinEnergy, 
                                       G4double Z, 
                                       G4double A = 0., 
                                       G4double cutEnergy = 0.,
                                       G4double maxEnergy = DBL_MAX) final;

  G4double CrossSectionPerVolume(const G4Material*,
				 const G4ParticleDefinition*,
				 G4double kineticEnergy,
				 G4double cutEnergy = 0.0,
				 G4double maxEnergy = DBL_MAX) final;

  void SampleSecondaries(std::vector<G4DynamicParticle*>*,
				 const G4MaterialCutsCouple*,
				 const G4DynamicParticle*,
				 G4double tmin = 0.0,
				 G4double maxEnergy = DBL_MAX) final;

  G4double ComputeF(G4double fr1, G4double fr2, G4double fr3, G4double kinEnergy);

  G4double ComputeF0(G4double fr1, G4double fr2, G4double fr3);

  G4double ComputeFS(G4double fr1, G4double fr2, G4double fr3, G4double kinEnergy);

  inline void SetDelta(G4double val) { if(val > 0.0) { fDelta = val; } };
  
  // hide assignment operator
  G4eplusTo3GammaOKVIModel & operator=
  (const  G4eplusTo3GammaOKVIModel &right) = delete;
  G4eplusTo3GammaOKVIModel(const  G4eplusTo3GammaOKVIModel&) = delete;

private:

  G4double fDelta;
  const G4ParticleDefinition* theGamma;
};

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......


#endif