Version: SMASH-1.5
constants.h
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1 /*
2  * Copyright (c) 2013-2018
3  * SMASH Team
4  *
5  * GNU General Public License (GPLv3 or later)
6  */
7 #ifndef SRC_INCLUDE_CONSTANTS_H_
8 #define SRC_INCLUDE_CONSTANTS_H_
9 
10 #include <cmath>
11 #include <cstdint>
12 #include <limits>
13 
20 namespace smash {
21 
25 constexpr double hbarc = 0.197327053;
26 
28 constexpr double fm2_mb = 0.1;
29 
31 constexpr double gev2_mb = hbarc * hbarc / fm2_mb;
32 
34 constexpr double really_small = 1.0e-6;
35 
39 constexpr double twopi = 2. * M_PI;
40 
42 constexpr double nuclear_density = 0.168;
43 
45 constexpr double small_number = 1.0e-4;
46 
52 constexpr double nucleon_mass = 0.938;
53 
59 constexpr double pion_mass = 0.138;
60 
66 constexpr double kaon_mass = 0.494;
67 
73 constexpr double omega_mass = 0.783;
74 
80 constexpr double a1_mass = 1.26;
86 constexpr double delta_mass = 1.232;
92 constexpr double deuteron_mass = 1.8756;
93 
95 constexpr double fine_structure = 7.2973525698e-3;
96 
108 constexpr double maximum_cross_section = 200.; // mb
109 
113 constexpr int maximum_rndm_seed_in_pythia = 900000000;
114 
121 constexpr double minimum_sqrts_pythia_can_handle = 10.0; // GeV
122 
128 constexpr std::uint32_t ID_PROCESS_PHOTON =
129  std::numeric_limits<std::uint32_t>::max();
130 
131 } // namespace smash
132 
133 #endif // SRC_INCLUDE_CONSTANTS_H_
constexpr double a1_mass
a1 mass in GeV.
Definition: constants.h:80
constexpr double really_small
Numerical error tolerance.
Definition: constants.h:34
constexpr std::uint32_t ID_PROCESS_PHOTON
Process ID for any photon process.
Definition: constants.h:128
constexpr double fm2_mb
mb <-> fm^2 conversion factor.
Definition: constants.h:28
constexpr double nucleon_mass
Nucleon mass in GeV.
Definition: constants.h:52
constexpr double hbarc
GeV <-> fm conversion factor.
Definition: constants.h:25
constexpr double maximum_cross_section
The maximal cross section (in mb) for which it is guaranteed that all collisions with this cross sect...
Definition: constants.h:108
constexpr double fine_structure
Fine-struture constant, approximately 1/137.
Definition: constants.h:95
constexpr double pion_mass
Pion mass in GeV.
Definition: constants.h:59
constexpr double twopi
.
Definition: constants.h:39
constexpr double minimum_sqrts_pythia_can_handle
Energy in GeV, below which hard reactions via pythia are impossible.
Definition: constants.h:121
constexpr double deuteron_mass
Deuteron mass in GeV.
Definition: constants.h:92
constexpr double gev2_mb
GeV^-2 <-> mb conversion factor.
Definition: constants.h:31
constexpr double kaon_mass
Kaon mass in GeV.
Definition: constants.h:66
constexpr double nuclear_density
Ground state density of symmetric nuclear matter [fm^-3].
Definition: constants.h:42
constexpr int maximum_rndm_seed_in_pythia
The maximum value of the random seed used in PYTHIA.
Definition: constants.h:113
constexpr double small_number
Physical error tolerance.
Definition: constants.h:45
constexpr double delta_mass
Delta mass in GeV.
Definition: constants.h:86
constexpr double omega_mass
omega mass in GeV.
Definition: constants.h:73
Definition: action.h:24