72 G4double Pmu = 517.6*MeV;
73 G4double mu_mass = 105.658*MeV;
74 G4double Emu = std::sqrt(Pmu*Pmu + mu_mass*mu_mass);
75 G4double Kmu = Emu - mu_mass;
77 G4double x0 = -6.99*m;
82 fParticleGun->SetParticlePosition(G4ThreeVector(x0,y0,z0));
83 fParticleGun->SetParticlePolarization(G4ThreeVector(0.,1.,0.));
84 fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0.,1.,0.));