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PhysicalConstants.h
Go to the documentation of this file.
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 namespace Units {
44
45 constexpr double pi = 3.14159265358979323846;
46 constexpr double twopi = 2*pi;
47 constexpr double halfpi = pi/2;
48 constexpr double pi2 = pi*pi;
49
50 constexpr double Avogadro = 6.0221367e+23/mole;
51
52 //
53 // c = 299.792458 mm/ns
54 // c^2 = 898.7404 (mm/ns)^2
55 //
56 constexpr double c_light = 2.99792458e+8 * m/s;
57 constexpr double c_squared = c_light * c_light;
58
59 //
60 // h = 4.13566e-12 MeV*ns
61 // hbar = 6.58212e-13 MeV*ns
62 // hbarc = 197.32705e-12 MeV*mm
63 //
64 constexpr double h_Planck = 6.6260755e-34 * joule*s;
65 constexpr double hbar_Planck = h_Planck/twopi;
66 constexpr double hbarc = hbar_Planck * c_light;
67 constexpr double hbarc_squared = hbarc * hbarc;
68
69 constexpr double electron_charge = - eplus; // see SystemOfUnits.h
70 constexpr double e_squared = eplus * eplus;
71
72 //
73 // amu_c2 - atomic equivalent mass unit
74 // amu - atomic mass unit
75 //
76 constexpr double electron_mass_c2 = 0.51099906 * MeV;
77 constexpr double proton_mass_c2 = 938.27231 * MeV;
78 constexpr double neutron_mass_c2 = 939.56563 * MeV;
79 constexpr double amu_c2 = 931.49432 * MeV;
80 constexpr double amu = amu_c2/c_squared;
81
82 //
83 // permeability of free space mu0 = 2.01334e-16 Mev*(ns*eplus)^2/mm
84 // permittivity of free space epsil0 = 5.52636e+10 eplus^2/(MeV*mm)
85 //
86 constexpr double mu0 = 4*pi*1.e-7 * henry/m;
87 constexpr double epsilon0 = 1./(c_squared*mu0);
88
89 //
90 // electromagnetic coupling = 1.43996e-12 MeV*mm/(eplus^2)
91 //
92 constexpr double elm_coupling = e_squared/(4*pi*epsilon0);
93 constexpr double fine_structure_const = elm_coupling/hbarc;
94 constexpr double classic_electr_radius = elm_coupling/electron_mass_c2;
95 constexpr double electron_Compton_length = hbarc/electron_mass_c2;
96 constexpr double Bohr_radius = electron_Compton_length/fine_structure_const;
97
98 constexpr double alpha_rcl2 = fine_structure_const
99 *classic_electr_radius
100 *classic_electr_radius;
101
102 constexpr double twopi_mc2_rcl2 = twopi*electron_mass_c2
103 *classic_electr_radius
104 *classic_electr_radius;
105
106 constexpr double k_Boltzmann = 8.617385e-11 * MeV/kelvin;
107
108 constexpr double STP_Temperature = 273.15*kelvin;
109 constexpr double STP_Pressure = 1.*atmosphere;
110 constexpr double kGasThreshold = 10.*mg/cm3;
111
112 constexpr double universe_mean_density = 1.e-25*g/cm3;
113
114 } // namespace Units
115 } // namespace Gaudi
116
117
118 #endif /* GAUDI_PHYSICAL_CONSTANTS_H */
119
120
121
122
123
Gaudi::Units::twopi
constexpr double twopi
Definition: PhysicalConstants.h:46
Gaudi::Units::s
constexpr double s
Definition: SystemOfUnits.h:134
Gaudi::Units::STP_Pressure
constexpr double STP_Pressure
Definition: PhysicalConstants.h:109
Gaudi::Units::eplus
constexpr double eplus
Definition: SystemOfUnits.h:140
Gaudi::Units::epsilon0
constexpr double epsilon0
Definition: PhysicalConstants.h:87
Gaudi::Units::mg
constexpr double mg
Definition: SystemOfUnits.h:174
Gaudi::Units::MeV
constexpr double MeV
Definition: SystemOfUnits.h:157
Gaudi::Units::henry
constexpr double henry
Definition: SystemOfUnits.h:238
Gaudi::Units::halfpi
constexpr double halfpi
Definition: PhysicalConstants.h:47
Gaudi::Units::universe_mean_density
constexpr double universe_mean_density
Definition: PhysicalConstants.h:112
Gaudi::Units::hbar_Planck
constexpr double hbar_Planck
Definition: PhysicalConstants.h:65
Gaudi::Units::c_squared
constexpr double c_squared
Definition: PhysicalConstants.h:57
Gaudi::Units::e_squared
constexpr double e_squared
Definition: PhysicalConstants.h:70
Gaudi::Units::elm_coupling
constexpr double elm_coupling
Definition: PhysicalConstants.h:92
Gaudi::Units::electron_Compton_length
constexpr double electron_Compton_length
Definition: PhysicalConstants.h:95
Gaudi::Units::neutron_mass_c2
constexpr double neutron_mass_c2
Definition: PhysicalConstants.h:78
Gaudi::Units::electron_charge
constexpr double electron_charge
Definition: PhysicalConstants.h:69
Gaudi::Units::proton_mass_c2
constexpr double proton_mass_c2
Definition: PhysicalConstants.h:77
Gaudi::Units::Avogadro
constexpr double Avogadro
Definition: PhysicalConstants.h:50
Gaudi::Units::m
constexpr double m
Definition: SystemOfUnits.h:93
Gaudi::Units::hbarc
constexpr double hbarc
Definition: PhysicalConstants.h:66
Gaudi::Units::joule
constexpr double joule
Definition: SystemOfUnits.h:154
Gaudi::Units::twopi_mc2_rcl2
constexpr double twopi_mc2_rcl2
Definition: PhysicalConstants.h:102
Gaudi::Units::kelvin
constexpr double kelvin
Definition: SystemOfUnits.h:243
Gaudi::Units::fine_structure_const
constexpr double fine_structure_const
Definition: PhysicalConstants.h:93
Gaudi::Units::k_Boltzmann
constexpr double k_Boltzmann
Definition: PhysicalConstants.h:106
Gaudi::Units::h_Planck
constexpr double h_Planck
Definition: PhysicalConstants.h:64
Gaudi::Units::hbarc_squared
constexpr double hbarc_squared
Definition: PhysicalConstants.h:67
Gaudi::Units::amu_c2
constexpr double amu_c2
Definition: PhysicalConstants.h:79
Gaudi::Units::mu0
constexpr double mu0
Definition: PhysicalConstants.h:86
Gaudi::Units::alpha_rcl2
constexpr double alpha_rcl2
Definition: PhysicalConstants.h:98
Gaudi::Units::kGasThreshold
constexpr double kGasThreshold
Definition: PhysicalConstants.h:110
Gaudi::Units::atmosphere
constexpr double atmosphere
Definition: SystemOfUnits.h:191
Gaudi::Units::pi2
constexpr double pi2
Definition: PhysicalConstants.h:48
Gaudi::Units::electron_mass_c2
constexpr double electron_mass_c2
Definition: PhysicalConstants.h:76
Gaudi::Units::c_light
constexpr double c_light
Definition: PhysicalConstants.h:56
Gaudi::Units::Bohr_radius
constexpr double Bohr_radius
Definition: PhysicalConstants.h:96
SystemOfUnits.h
Gaudi::Units::mole
constexpr double mole
Definition: SystemOfUnits.h:248
Gaudi::Units::STP_Temperature
constexpr double STP_Temperature
Definition: PhysicalConstants.h:108
Gaudi::Units::g
constexpr double g
Definition: SystemOfUnits.h:173
Gaudi
Helper functions to set/get the application return code.
Definition: __init__.py:1
Gaudi::Units::pi
constexpr double pi
Definition: PhysicalConstants.h:45
Gaudi::Units::cm3
constexpr double cm3
Definition: SystemOfUnits.h:91
Gaudi::Units::classic_electr_radius
constexpr double classic_electr_radius
Definition: PhysicalConstants.h:94
Gaudi::Units::amu
constexpr double amu
Definition: PhysicalConstants.h:80