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#include "G4HETCProton.hh"

G4double G4HETCProton::K(const G4Fragment & aFragment)
{
  if (GetStage() != 1) return 1.0;
  // Number of protons in projectile
  G4double Pa = static_cast<G4int>(aFragment.GetParticleDefinition()->GetPDGCharge());
  // Number of neutrons in projectile 
  G4double Na = aFragment.GetParticleDefinition()->GetBaryonNumber();
  G4double TargetA = aFragment.GetA() - Na;
  G4double TargetZ = aFragment.GetZ() - Pa;
  Na -= Pa;
  G4double r = TargetZ/TargetA;


  G4double P = aFragment.GetNumberOfParticles();
  G4double H = aFragment.GetNumberOfHoles();

  G4double result = 0.0;
  if (P > 0)
    {
      result = (H*r + Pa)/P;
      
      result /= TargetZ/TargetA;
    }

  return std::max(0.0,result);
}