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QQbar_threshold
constants.hpp
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1 
35 #pragma once
36 #include <cmath>
37 
39 namespace QQbar_threshold{
40 
42  constexpr double alpha_s_mZ = 0.1184;
44  constexpr double alpha_mZ = 1/128.944;
46  constexpr double alpha_Y = 1/132.274;
48  constexpr double mu_alpha_Y = 10.2;
50  constexpr double mZ = 91.1876;
52  constexpr double mW = 80.385;
53 
55  constexpr double G_F = 0.000011663787;
56 
58  constexpr double m_Higgs = 125.;
59 
61  constexpr double alpha_QED = 1/137.035999074;
62 
64  constexpr double e_u = 2./3.;
66  constexpr double e_d = -1./3.;
68  constexpr double e = -1;
70  constexpr double cw2 = mW*mW/(mZ*mZ);
72  constexpr double sw2 = 1 - cw2;
73 
75  constexpr double T3_nu = 1./2.;
77  constexpr double T3_e = -1./2.;
79  constexpr double T3_u = 1./2.;
81  constexpr double T3_d = -1./2.;
82 
84  constexpr double mb_SI = 4.203;
86  constexpr double mu_thr = 2*mb_SI;
87 
89  constexpr int nl_bottom = 4;
91  constexpr int nl_top = 5;
92 
94  constexpr double mu_f_bottom = 2.;
95 
97  constexpr double mu_f_top = 20.;
98 
100  constexpr double invGeV2_to_pb = 389379300.;
101 
103 
107  inline double axial_Z_coupling(double T3, double){
108  return T3/(2*sqrt(sw2*cw2));
109  }
110 
112 
117  inline double vector_Z_coupling(double T3, double e){
118  return (T3 - 2*e*sw2)/(2*sqrt(sw2*cw2));
119  }
120 
121  namespace detail{
122  enum coupling{
123  axial, vector,
124  last_coupling = vector
125  };
126 
128  //TODO: make constexpr (requires constexpr sqrt)
129  template<coupling c>
130  double c_e();
131 
132  template<>
133  inline double c_e<axial>(){
134  static const double a_e = axial_Z_coupling(T3_e, e);
135  return a_e;
136  }
137 
138  template<>
139  inline double c_e<vector>(){
140  static const double v_e = vector_Z_coupling(T3_e, e);
141  return v_e;
142  }
143 
145  //TODO: make constexpr (requires constexpr sqrt)
146  template<coupling c>
147  double c_nu();
148 
149  template<>
150  inline double c_nu<axial>(){
151  static const double a_nu = axial_Z_coupling(T3_nu, 0);
152  return a_nu;
153  }
154 
155  template<>
156  inline double c_nu<vector>(){
157  static const double v_nu = vector_Z_coupling(T3_nu, 0);
158  return v_nu;
159  }
160  }
161 
162 }
Definition: alpha_s.hpp:37
double vector_Z_coupling(double T3, double e)
Vector coupling of fermion to Z boson.
Definition: constants.hpp:117
constexpr int nl_top
Number of light flavours for top-related functions.
Definition: constants.hpp:91
constexpr double mu_alpha_Y
Typical scale for Y resonances.
Definition: constants.hpp:48
constexpr double T3_u
Weak isospin of top.
Definition: constants.hpp:79
constexpr double mZ
Mass of the Z boson.
Definition: constants.hpp:50
constexpr double e_u
Electric charge of the top quark in units of the positron charge.
Definition: constants.hpp:64
constexpr double alpha_QED
Fine structure constant.
Definition: constants.hpp:61
constexpr double alpha_mZ
QED coupling at the scale mZ.
Definition: constants.hpp:44
constexpr double sw2
sine of the weak mixing angle squared
Definition: constants.hpp:72
constexpr double T3_e
Weak isospin of electron.
Definition: constants.hpp:77
constexpr double m_Higgs
Default value for mass of the Higgs boson.
Definition: constants.hpp:58
constexpr double mb_SI
Reference scale-invariant mass for bottom quarks.
Definition: constants.hpp:84
constexpr double alpha_s_mZ
Default value for strong coupling at the scale mZ.
Definition: constants.hpp:42
constexpr double mu_thr
Decoupling threshold for bottom quarks.
Definition: constants.hpp:86
constexpr double T3_nu
Weak isospin of neutrino.
Definition: constants.hpp:75
constexpr double G_F
Fermi constant - this is exclusively used for calculating the top width.
Definition: constants.hpp:55
constexpr int nl_bottom
Number of light flavours for bottom-related functions.
Definition: constants.hpp:89
double axial_Z_coupling(double T3, double)
Axial vector coupling of fermion to Z boson.
Definition: constants.hpp:107
constexpr double e_d
Electric charge of the bottom quark in units of the positron charge.
Definition: constants.hpp:66
constexpr double T3_d
Weak isospin of bottom.
Definition: constants.hpp:81
constexpr double mu_f_bottom
Default PS scale for bottom.
Definition: constants.hpp:94
constexpr double cw2
cosine of the weak mixing angle squared
Definition: constants.hpp:70
constexpr double mW
Mass of the W boson.
Definition: constants.hpp:52
constexpr double e
Electric charge of the electron in units of the positron charge.
Definition: constants.hpp:68
constexpr double mu_f_top
Default PS scale for top.
Definition: constants.hpp:97
constexpr double alpha_Y
QED coupling at the scale mu_alpha_Y.
Definition: constants.hpp:46
constexpr double invGeV2_to_pb
Conversion factor from 1/GeV^2 to picobarn.
Definition: constants.hpp:100