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PhysicalConstants.h
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1 // -*- C++ -*-
2 // ----------------------------------------------------------------------
3 // HEP coherent Physical Constants
4 //
5 // This file has been provided by Geant4 (simulation toolkit for HEP).
6 //
7 // The basic units are :
8 // millimeter
9 // nanosecond
10 // Mega electron Volt
11 // positon charge
12 // degree Kelvin
13 // amount of substance (mole)
14 // luminous intensity (candela)
15 // radian
16 // steradian
17 //
18 // Below is a non exhaustive list of Physical CONSTANTS,
19 // computed in the Internal HEP System Of Units.
20 //
21 // Most of them are extracted from the Particle Data Book :
22 // Phys. Rev. D volume 50 3-1 (1994) page 1233
23 //
24 // ...with a meaningful (?) name ...
25 //
26 // You can add your own constants.
27 //
28 // Author: M.Maire
29 //
30 // History:
31 //
32 // 23.02.96 Created
33 // 26.03.96 Added constants for standard conditions of temperature
34 // and pressure; also added Gas threshold.
35 // 28.04.06 Imported from CLHEP into GaudiKernel -- HD
36
37 #ifndef GAUDI_PHYSICAL_CONSTANTS_H
38 #define GAUDI_PHYSICAL_CONSTANTS_H
39
40 #include "GaudiKernel/SystemOfUnits.h"
41
42 namespace Gaudi
43 {
44 namespace Units
45 {
46
47 constexpr double pi = 3.14159265358979323846;
48 constexpr double twopi = 2 * pi;
49 constexpr double halfpi = pi / 2;
50 constexpr double pi2 = pi * pi;
51
52 constexpr double Avogadro = 6.0221367e+23 / mole;
53
54 //
55 // c = 299.792458 mm/ns
56 // c^2 = 898.7404 (mm/ns)^2
57 //
58 constexpr double c_light = 2.99792458e+8 * m / s;
59 constexpr double c_squared = c_light * c_light;
60
61 //
62 // h = 4.13566e-12 MeV*ns
63 // hbar = 6.58212e-13 MeV*ns
64 // hbarc = 197.32705e-12 MeV*mm
65 //
66 constexpr double h_Planck = 6.6260755e-34 * joule * s;
67 constexpr double hbar_Planck = h_Planck / twopi;
68 constexpr double hbarc = hbar_Planck * c_light;
69 constexpr double hbarc_squared = hbarc * hbarc;
70
71 constexpr double electron_charge = -eplus; // see SystemOfUnits.h
72 constexpr double e_squared = eplus * eplus;
73
74 //
75 // amu_c2 - atomic equivalent mass unit
76 // amu - atomic mass unit
77 //
78 constexpr double electron_mass_c2 = 0.51099906 * MeV;
79 constexpr double proton_mass_c2 = 938.27231 * MeV;
80 constexpr double neutron_mass_c2 = 939.56563 * MeV;
81 constexpr double amu_c2 = 931.49432 * MeV;
82 constexpr double amu = amu_c2 / c_squared;
83
84 //
85 // permeability of free space mu0 = 2.01334e-16 Mev*(ns*eplus)^2/mm
86 // permittivity of free space epsil0 = 5.52636e+10 eplus^2/(MeV*mm)
87 //
88 constexpr double mu0 = 4 * pi * 1.e-7 * henry / m;
89 constexpr double epsilon0 = 1. / ( c_squared * mu0 );
90
91 //
92 // electromagnetic coupling = 1.43996e-12 MeV*mm/(eplus^2)
93 //
94 constexpr double elm_coupling = e_squared / ( 4 * pi * epsilon0 );
95 constexpr double fine_structure_const = elm_coupling / hbarc;
96 constexpr double classic_electr_radius = elm_coupling / electron_mass_c2;
97 constexpr double electron_Compton_length = hbarc / electron_mass_c2;
98 constexpr double Bohr_radius = electron_Compton_length / fine_structure_const;
99
100 constexpr double alpha_rcl2 = fine_structure_const * classic_electr_radius * classic_electr_radius;
101
102 constexpr double twopi_mc2_rcl2 = twopi * electron_mass_c2 * classic_electr_radius * classic_electr_radius;
103
104 constexpr double k_Boltzmann = 8.617385e-11 * MeV / kelvin;
105
106 constexpr double STP_Temperature = 273.15 * kelvin;
107 constexpr double STP_Pressure = 1. * atmosphere;
108 constexpr double kGasThreshold = 10. * mg / cm3;
109
110 constexpr double universe_mean_density = 1.e-25 * g / cm3;
111
112 } // namespace Units
113 } // namespace Gaudi
114
115 #endif /* GAUDI_PHYSICAL_CONSTANTS_H */
Gaudi::Units::twopi
constexpr double twopi
Definition: PhysicalConstants.h:48
Gaudi::Units::s
constexpr double s
Definition: SystemOfUnits.h:135
Gaudi::Units::STP_Pressure
constexpr double STP_Pressure
Definition: PhysicalConstants.h:107
Gaudi::Units::eplus
constexpr double eplus
Definition: SystemOfUnits.h:141
Gaudi::Units::epsilon0
constexpr double epsilon0
Definition: PhysicalConstants.h:89
Gaudi::Units::mg
constexpr double mg
Definition: SystemOfUnits.h:175
Gaudi::Units::MeV
constexpr double MeV
Definition: SystemOfUnits.h:158
Gaudi::Units::henry
constexpr double henry
Definition: SystemOfUnits.h:239
Gaudi::Units::halfpi
constexpr double halfpi
Definition: PhysicalConstants.h:49
Gaudi::Units::universe_mean_density
constexpr double universe_mean_density
Definition: PhysicalConstants.h:110
Gaudi::Units::hbar_Planck
constexpr double hbar_Planck
Definition: PhysicalConstants.h:67
Gaudi::Units::c_squared
constexpr double c_squared
Definition: PhysicalConstants.h:59
Gaudi::Units::e_squared
constexpr double e_squared
Definition: PhysicalConstants.h:72
Gaudi::Units::elm_coupling
constexpr double elm_coupling
Definition: PhysicalConstants.h:94
Gaudi::Units::electron_Compton_length
constexpr double electron_Compton_length
Definition: PhysicalConstants.h:97
Gaudi::Units::neutron_mass_c2
constexpr double neutron_mass_c2
Definition: PhysicalConstants.h:80
Gaudi::Units::electron_charge
constexpr double electron_charge
Definition: PhysicalConstants.h:71
Gaudi::Units::proton_mass_c2
constexpr double proton_mass_c2
Definition: PhysicalConstants.h:79
Gaudi::Units::Avogadro
constexpr double Avogadro
Definition: PhysicalConstants.h:52
Gaudi::Units::m
constexpr double m
Definition: SystemOfUnits.h:94
Gaudi::Units::hbarc
constexpr double hbarc
Definition: PhysicalConstants.h:68
Gaudi::Units::joule
constexpr double joule
Definition: SystemOfUnits.h:155
Gaudi::Units::twopi_mc2_rcl2
constexpr double twopi_mc2_rcl2
Definition: PhysicalConstants.h:102
Gaudi::Units::kelvin
constexpr double kelvin
Definition: SystemOfUnits.h:244
Gaudi::Units::fine_structure_const
constexpr double fine_structure_const
Definition: PhysicalConstants.h:95
Gaudi::Units::k_Boltzmann
constexpr double k_Boltzmann
Definition: PhysicalConstants.h:104
Gaudi::Units::h_Planck
constexpr double h_Planck
Definition: PhysicalConstants.h:66
Gaudi::Units::hbarc_squared
constexpr double hbarc_squared
Definition: PhysicalConstants.h:69
Gaudi::Units::amu_c2
constexpr double amu_c2
Definition: PhysicalConstants.h:81
Gaudi::Units::mu0
constexpr double mu0
Definition: PhysicalConstants.h:88
Gaudi::Units::alpha_rcl2
constexpr double alpha_rcl2
Definition: PhysicalConstants.h:100
Gaudi::Units::kGasThreshold
constexpr double kGasThreshold
Definition: PhysicalConstants.h:108
Gaudi::Units::atmosphere
constexpr double atmosphere
Definition: SystemOfUnits.h:192
Gaudi::Units::pi2
constexpr double pi2
Definition: PhysicalConstants.h:50
Gaudi::Units::electron_mass_c2
constexpr double electron_mass_c2
Definition: PhysicalConstants.h:78
Gaudi::Units::c_light
constexpr double c_light
Definition: PhysicalConstants.h:58
Gaudi::Units::Bohr_radius
constexpr double Bohr_radius
Definition: PhysicalConstants.h:98
SystemOfUnits.h
Gaudi::Units::mole
constexpr double mole
Definition: SystemOfUnits.h:249
Gaudi::Units::STP_Temperature
constexpr double STP_Temperature
Definition: PhysicalConstants.h:106
Gaudi::Units::g
constexpr double g
Definition: SystemOfUnits.h:174
Gaudi
Helper functions to set/get the application return code.
Definition: __init__.py:1
Gaudi::Units::pi
constexpr double pi
Definition: PhysicalConstants.h:47
Gaudi::Units::cm3
constexpr double cm3
Definition: SystemOfUnits.h:92
Gaudi::Units::classic_electr_radius
constexpr double classic_electr_radius
Definition: PhysicalConstants.h:96
Gaudi::Units::amu
constexpr double amu
Definition: PhysicalConstants.h:82