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PhysicalConstants.h
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1 // -*- C++ -*-
2 // $Id:$
3 // ----------------------------------------------------------------------
4 // HEP coherent Physical Constants
5 //
6 // This file has been provided by Geant4 (simulation toolkit for HEP).
7 //
8 // The basic units are :
9 // millimeter
10 // nanosecond
11 // Mega electron Volt
12 // positon charge
13 // degree Kelvin
14 // amount of substance (mole)
15 // luminous intensity (candela)
16 // radian
17 // steradian
18 //
19 // Below is a non exhaustive list of Physical CONSTANTS,
20 // computed in the Internal HEP System Of Units.
21 //
22 // Most of them are extracted from the Particle Data Book :
23 // Phys. Rev. D volume 50 3-1 (1994) page 1233
24 //
25 // ...with a meaningful (?) name ...
26 //
27 // You can add your own constants.
28 //
29 // Author: M.Maire
30 //
31 // History:
32 //
33 // 23.02.96 Created
34 // 26.03.96 Added constants for standard conditions of temperature
35 // and pressure; also added Gas threshold.
36 // 29.04.08 use PDG 2006 values
37 // 03.11.08 use PDG 2008 values
38 
39 #ifndef HEP_PHYSICAL_CONSTANTS_H
40 #define HEP_PHYSICAL_CONSTANTS_H
41 
43 
44 namespace CLHEP {
45 
46 //
47 //
48 //
49 static constexpr double Avogadro = 6.02214179e+23/mole;
50 
51 //
52 // c = 299.792458 mm/ns
53 // c^2 = 898.7404 (mm/ns)^2
54 //
55 static constexpr double c_light = 2.99792458e+8 * m/s;
56 static constexpr double c_squared = c_light * c_light;
57 
58 //
59 // h = 4.13566e-12 MeV*ns
60 // hbar = 6.58212e-13 MeV*ns
61 // hbarc = 197.32705e-12 MeV*mm
62 //
63 static constexpr double h_Planck = 6.62606896e-34 * joule*s;
64 static constexpr double hbar_Planck = h_Planck/twopi;
65 static constexpr double hbarc = hbar_Planck * c_light;
66 static constexpr double hbarc_squared = hbarc * hbarc;
67 
68 //
69 //
70 //
71 static constexpr double electron_charge = - eplus; // see SystemOfUnits.h
72 static constexpr double e_squared = eplus * eplus;
73 
74 //
75 // amu_c2 - atomic equivalent mass unit
76 // - AKA, unified atomic mass unit (u)
77 // amu - atomic mass unit
78 //
79 static constexpr double electron_mass_c2 = 0.510998910 * MeV;
80 static constexpr double proton_mass_c2 = 938.272013 * MeV;
81 static constexpr double neutron_mass_c2 = 939.56536 * MeV;
82 static constexpr double amu_c2 = 931.494028 * MeV;
83 static constexpr double amu = amu_c2/c_squared;
84 
85 //
86 // permeability of free space mu0 = 2.01334e-16 Mev*(ns*eplus)^2/mm
87 // permittivity of free space epsil0 = 5.52636e+10 eplus^2/(MeV*mm)
88 //
89 static constexpr double mu0 = 4*pi*1.e-7 * henry/m;
90 static constexpr double epsilon0 = 1./(c_squared*mu0);
91 
92 //
93 // electromagnetic coupling = 1.43996e-12 MeV*mm/(eplus^2)
94 //
95 static constexpr double elm_coupling = e_squared/(4*pi*epsilon0);
96 static constexpr double fine_structure_const = elm_coupling/hbarc;
100 
101 static constexpr double alpha_rcl2 = fine_structure_const
104 
105 static constexpr double twopi_mc2_rcl2 = twopi*electron_mass_c2
108 //
109 //
110 //
111 static constexpr double k_Boltzmann = 8.617343e-11 * MeV/kelvin;
112 
113 //
114 //
115 //
116 static constexpr double STP_Temperature = 273.15*kelvin;
117 static constexpr double STP_Pressure = 1.*atmosphere;
118 static constexpr double kGasThreshold = 10.*mg/cm3;
119 
120 //
121 //
122 //
123 static constexpr double universe_mean_density = 1.e-25*g/cm3;
124 
125 } // namespace CLHEP
126 
127 #endif /* HEP_PHYSICAL_CONSTANTS_H */
128 
129 
130 
131 
132 
static constexpr double m
static constexpr double kGasThreshold
static constexpr double k_Boltzmann
static constexpr double h_Planck
static constexpr double proton_mass_c2
static constexpr double Bohr_radius
static constexpr double twopi_mc2_rcl2
static constexpr double epsilon0
static constexpr double hbarc
static constexpr double hbarc_squared
static constexpr double STP_Pressure
static constexpr double mg
static constexpr double electron_charge
static constexpr double Avogadro
static constexpr double g
static constexpr double electron_mass_c2
static constexpr double STP_Temperature
static constexpr double classic_electr_radius
static constexpr double neutron_mass_c2
static constexpr double MeV
static constexpr double amu
static constexpr double amu_c2
static constexpr double eplus
static constexpr double joule
static constexpr double e_squared
static constexpr double s
static constexpr double c_squared
static constexpr double c_light
static constexpr double universe_mean_density
static constexpr double mu0
static constexpr double elm_coupling
static constexpr double alpha_rcl2
static constexpr double mole
static constexpr double henry
static constexpr double fine_structure_const
static constexpr double hbar_Planck
static constexpr double twopi
Definition: SystemOfUnits.h:55
static constexpr double kelvin
static constexpr double electron_Compton_length
static constexpr double pi
Definition: SystemOfUnits.h:54
static constexpr double atmosphere
static constexpr double cm3