include/G4HepEm/G4HepEmConstants.hh

0001
0002 #ifndef G4HepEmConstants__HH
0003 #define G4HepEmConstants__HH
0004
0005
0006 // CLHEP::pi
0007 static constexpr double kPi                = 3.1415926535897931e+00;
0008 static constexpr double k2Pi               = 2.0 * kPi;
0009
0010 // e- m_0c^2 in [MeV] CLHEP::electron_mass_c2
0011 static constexpr double kElectronMassC2    = 5.1099890999999997e-01;
0012 static constexpr double kInvElectronMassC2 = 1.0 / kElectronMassC2;
0013
0014 // CLHEP::fine_structure_const
0015 static constexpr double kAlpha             = 7.2973525653052150e-03;
0016
0017 /** \f$ \pi r_0^2\f$ */
0018 // CLHEP::pi*CLHEP::classic_electr_radius*CLHEP::classic_electr_radius
0019 static constexpr double kPir02             = 2.4946724123674787e-23;
0020
0021 /** Migdal's constant: \f$ 4\pi r_0*[\hbar c/(m_0c^2)]^2 \f$ */
0022 // 4.0 * CLHEP::pi * CLHEP::classic_electr_radius * CLHEP::electron_Compton_length * CLHEP::electron_Compton_length
0023 static constexpr double kMigdalConst       = 5.2804955733859579e-30;
0024
0025 /** LPM constant: \f$ \alpha(m_0c^2)^2/(4\pi*\hbar c) \f$ */
0026 // CLHEP::fine_structure_const * CLHEP::electron_mass_c2 * CLHEP::electron_mass_c2 / (4.0 * CLHEP::pi * CLHEP::hbarc)
0027 static constexpr double kLPMconstant       = 7.6843819381368661e+05;
0028
0029 static constexpr double kALargeValue       = 1.0E+20;
0030
0031
0032 #endif  // G4HepEmConstants__HH