| Geant4 Cross Reference |
1 // -*- C++ -*- 1 // -*- C++ -*-
2 // ------------------------------------------- 2 // ----------------------------------------------------------------------
3 // HEP coherent Physical Constants 3 // HEP coherent Physical Constants
4 // 4 //
5 // This file has been provided by Geant4 (simu 5 // This file has been provided by Geant4 (simulation toolkit for HEP).
6 // 6 //
7 // The basic units are : 7 // The basic units are :
8 // millimeter 8 // millimeter
9 // nanosecond 9 // nanosecond
10 // Mega electron Volt 10 // Mega electron Volt
11 // positon charge 11 // positon charge
12 // degree Kelvin 12 // degree Kelvin
13 // amount of substance (mole) 13 // amount of substance (mole)
14 // luminous intensity (candela) 14 // luminous intensity (candela)
15 // radian 15 // radian
16 // steradian 16 // steradian
17 // 17 //
18 // Below is a non exhaustive list of Physical 18 // Below is a non exhaustive list of Physical CONSTANTS,
19 // computed in the Internal HEP System Of Unit 19 // computed in the Internal HEP System Of Units.
20 // 20 //
21 // Most of them are extracted from the Particl 21 // Most of them are extracted from the Particle Data Book :
22 // Phys. Rev. D volume 50 3-1 (1994) p 22 // Phys. Rev. D volume 50 3-1 (1994) page 1233
23 // 23 //
24 // ...with a meaningful (?) name ... 24 // ...with a meaningful (?) name ...
25 // 25 //
26 // You can add your own constants. 26 // You can add your own constants.
27 // 27 //
28 // Author: M.Maire 28 // Author: M.Maire
29 // 29 //
30 // History: 30 // History:
31 // 31 //
32 // 23.02.96 Created 32 // 23.02.96 Created
33 // 26.03.96 Added constants for standard condi 33 // 26.03.96 Added constants for standard conditions of temperature
34 // and pressure; also added Gas thres 34 // and pressure; also added Gas threshold.
35 // 29.04.08 Use PDG 2006 values 35 // 29.04.08 Use PDG 2006 values
36 // 03.11.08 Use PDG 2008 values 36 // 03.11.08 Use PDG 2008 values
37 // 17.07.20 Use PDG 2019 values 37 // 17.07.20 Use PDG 2019 values
38 // 06.05.21 Added Bohr_magneton and nuclear_ma 38 // 06.05.21 Added Bohr_magneton and nuclear_magneton constants
39 39
40 #ifndef HEP_PHYSICAL_CONSTANTS_H 40 #ifndef HEP_PHYSICAL_CONSTANTS_H
41 #define HEP_PHYSICAL_CONSTANTS_H 41 #define HEP_PHYSICAL_CONSTANTS_H
42 42
43 #include "CLHEP/Units/SystemOfUnits.h" 43 #include "CLHEP/Units/SystemOfUnits.h"
44 44
45 namespace CLHEP { 45 namespace CLHEP {
46 46
47 // 47 //
48 // 48 //
49 // 49 //
50 static constexpr double Avogadro = 6.02214076e 50 static constexpr double Avogadro = 6.02214076e+23/mole;
51 51
52 // 52 //
53 // c = 299.792458 mm/ns 53 // c = 299.792458 mm/ns
54 // c^2 = 898.7404 (mm/ns)^2 54 // c^2 = 898.7404 (mm/ns)^2
55 // 55 //
56 static constexpr double c_light = 2.99792458 56 static constexpr double c_light = 2.99792458e+8 * m/s;
57 static constexpr double c_squared = c_light * 57 static constexpr double c_squared = c_light * c_light;
58 58
59 // 59 //
60 // h = 4.13566e-12 MeV*ns 60 // h = 4.13566e-12 MeV*ns
61 // hbar = 6.58212e-13 MeV*ns 61 // hbar = 6.58212e-13 MeV*ns
62 // hbarc = 197.32705e-12 MeV*mm 62 // hbarc = 197.32705e-12 MeV*mm
63 // 63 //
64 static constexpr double h_Planck = 6.6260 64 static constexpr double h_Planck = 6.62607015e-34 * joule*s;
65 static constexpr double hbar_Planck = h_Plan 65 static constexpr double hbar_Planck = h_Planck/twopi;
66 static constexpr double hbarc = hbar_P 66 static constexpr double hbarc = hbar_Planck * c_light;
67 static constexpr double hbarc_squared = hbarc 67 static constexpr double hbarc_squared = hbarc * hbarc;
68 68
69 // 69 //
70 // 70 //
71 // 71 //
72 static constexpr double electron_charge = - ep 72 static constexpr double electron_charge = - eplus; // see SystemOfUnits.h
73 static constexpr double e_squared = eplus * ep 73 static constexpr double e_squared = eplus * eplus;
74 74
75 // 75 //
76 // amu_c2 - atomic equivalent mass unit 76 // amu_c2 - atomic equivalent mass unit
77 // - AKA, unified atomic mass unit (u) 77 // - AKA, unified atomic mass unit (u)
78 // amu - atomic mass unit 78 // amu - atomic mass unit
79 // 79 //
80 static constexpr double electron_mass_c2 = 0.5 80 static constexpr double electron_mass_c2 = 0.510998910 * MeV;
81 static constexpr double proton_mass_c2 = 938 81 static constexpr double proton_mass_c2 = 938.272013 * MeV;
82 static constexpr double neutron_mass_c2 = 939 82 static constexpr double neutron_mass_c2 = 939.56536 * MeV;
83 static constexpr double amu_c2 = 931 83 static constexpr double amu_c2 = 931.494028 * MeV;
84 static constexpr double amu = amu 84 static constexpr double amu = amu_c2/c_squared;
85 85
86 // 86 //
87 // permeability of free space mu0 = 2.01334 87 // permeability of free space mu0 = 2.01334e-16 Mev*(ns*eplus)^2/mm
88 // permittivity of free space epsil0 = 5.52636 88 // permittivity of free space epsil0 = 5.52636e+10 eplus^2/(MeV*mm)
89 // 89 //
90 static constexpr double mu0 = 4*pi*1.e-7 90 static constexpr double mu0 = 4*pi*1.e-7 * henry/m;
91 static constexpr double epsilon0 = 1./(c_squar 91 static constexpr double epsilon0 = 1./(c_squared*mu0);
92 92
93 // 93 //
94 // electromagnetic coupling = 1.43996e-12 MeV* 94 // electromagnetic coupling = 1.43996e-12 MeV*mm/(eplus^2)
95 // 95 //
96 static constexpr double elm_coupling 96 static constexpr double elm_coupling = e_squared/(4*pi*epsilon0);
97 static constexpr double fine_structure_const 97 static constexpr double fine_structure_const = elm_coupling/hbarc;
98 static constexpr double classic_electr_radius 98 static constexpr double classic_electr_radius = elm_coupling/electron_mass_c2;
99 static constexpr double electron_Compton_lengt 99 static constexpr double electron_Compton_length = hbarc/electron_mass_c2;
100 static constexpr double Bohr_radius = electron 100 static constexpr double Bohr_radius = electron_Compton_length/fine_structure_const;
101 101
102 static constexpr double alpha_rcl2 = fine_stru 102 static constexpr double alpha_rcl2 = fine_structure_const
103 *classic_el 103 *classic_electr_radius
104 *classic_el 104 *classic_electr_radius;
105 105
106 static constexpr double twopi_mc2_rcl2 = twopi 106 static constexpr double twopi_mc2_rcl2 = twopi*electron_mass_c2
107 * 107 *classic_electr_radius
108 * 108 *classic_electr_radius;
109 109
110 static constexpr double Bohr_magneton = (eplus 110 static constexpr double Bohr_magneton = (eplus*hbarc*c_light)/(2*electron_mass_c2);
111 static constexpr double nuclear_magneton = (ep 111 static constexpr double nuclear_magneton = (eplus*hbarc*c_light)/(2*proton_mass_c2);
112 112
113 // 113 //
114 // 114 //
115 // 115 //
116 static constexpr double k_Boltzmann = 8.617333 116 static constexpr double k_Boltzmann = 8.617333e-11 * MeV/kelvin;
117 117
118 // 118 //
119 // 119 //
120 // 120 //
121 static constexpr double STP_Temperature = 273. 121 static constexpr double STP_Temperature = 273.15*kelvin;
122 static constexpr double STP_Pressure = 1.*a 122 static constexpr double STP_Pressure = 1.*atmosphere;
123 static constexpr double kGasThreshold = 10.* 123 static constexpr double kGasThreshold = 10.*mg/cm3;
124 124
125 // 125 //
126 // 126 //
127 // 127 //
128 static constexpr double universe_mean_density 128 static constexpr double universe_mean_density = 1.e-25*g/cm3;
129 129
130 } // namespace CLHEP 130 } // namespace CLHEP
131 131
132 #endif /* HEP_PHYSICAL_CONSTANTS_H */ 132 #endif /* HEP_PHYSICAL_CONSTANTS_H */
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