32 #if __cplusplus >= 201402L 33 #define QCD_CONSTEXPR_AFTER_CXX14 constexpr 35 #define QCD_CONSTEXPR_AFTER_CXX14 40 constexpr
unsigned gamma_m_max_order = 4;
45 constexpr
double pi = 3.141592653589793238462643383279;
46 constexpr
double zeta_3 = 1.202056903159594285399738161511449990765;
47 constexpr
double zeta_4 = pi*pi*pi*pi/90.;
48 constexpr
double zeta_5 = 1.036927755143369926331365486457034168057;
49 constexpr
double zeta_6 = 1.017343061984449139714517929790920527902;
50 constexpr
double zeta_7 = 1.008349277381922826839797549849796759600;
52 constexpr
auto max_order = gamma_m_max_order;
57 constexpr
double gamma_m_00 = 1;
59 constexpr
double gamma_m_10 = 101./24.;
60 constexpr
double gamma_m_11 = -5./36.;
62 constexpr
double gamma_m_20 = 1249./64.;
63 constexpr
double gamma_m_21 = -277./216. - 5./6.*zeta_3;
64 constexpr
double gamma_m_22 = -35./1296.;
66 constexpr
double gamma_m_30 =
67 4603055./41472. + 530./27.*zeta_3 - 275./8.*zeta_5;
68 constexpr
double gamma_m_31 =
69 -91723./6912. - 2137./144.*zeta_3 + 55./16.*zeta_4 + 575./72.*zeta_5;
70 constexpr
double gamma_m_32 =
71 2621./31104. + 25./72.*zeta_3 - 5./24.*zeta_4;
72 constexpr
double gamma_m_33 = -83./15552. + zeta_3/108.;
74 constexpr
double gamma_m_40 =
75 + 99512327./165888. + 23201233./124416.*zeta_3 + 3025./32.*zeta_3*zeta_3
76 - 349063./4608.*zeta_4 - 28969645./31104.*zeta_5 + 15125./64.*zeta_6
79 constexpr
double gamma_m_41 =
80 - 150736283./1492992. - 391813./2592.*zeta_3 - 2365./288.*zeta_3*zeta_3
81 + 1019371./13824.*zeta_4 + 12469045./62208.*zeta_5 - 39875./576.*zeta_6
84 constexpr
double gamma_m_42 =
85 + 660371./373248. + 251353./31104.*zeta_3 + 725./432.*zeta_3*zeta_3 -
86 41575./6912.*zeta_4 - 33005./10368.*zeta_5 + 2875./864.*zeta_6
88 constexpr
double gamma_m_43 =
89 91865./1492992. + 803./5184.*zeta_3 + 7./144.*zeta_4 - 5./27.*zeta_5
91 constexpr
double gamma_m_44 = -65./62208. - 5./3888.*zeta_3 + zeta_4/432.;
93 constexpr
auto max_nf_pow =
94 std::array<unsigned,1u + max_order>{{0u, 1u, 2u, 3u, 4u}};
96 inline QCD_CONSTEXPR_AFTER_CXX14
97 unsigned coeffs_start_index(
unsigned order){
100 (1u + max_nf_pow[order-1] + coeffs_start_index(order-1))
104 constexpr
auto coeffs = std::array<double,15>{{
106 gamma_m_10, gamma_m_11,
107 gamma_m_20, gamma_m_21, gamma_m_22,
108 gamma_m_30, gamma_m_31, gamma_m_32, gamma_m_33,
109 gamma_m_40, gamma_m_41, gamma_m_42, gamma_m_43, gamma_m_44
112 inline QCD_CONSTEXPR_AFTER_CXX14
116 return max_nf_pow[order];
119 inline QCD_CONSTEXPR_AFTER_CXX14
124 return( coeffs[coeffs_start_index(order) + nfpow] );
127 inline QCD_CONSTEXPR_AFTER_CXX14
128 double helper(
unsigned order,
int nf,
unsigned nf_pow){
131 (nf_pow == max_nf_pow[order])?
137 inline QCD_CONSTEXPR_AFTER_CXX14
138 double gamma_m(
unsigned order,
int nf){
141 return helper(order, nf, 0);
144 inline QCD_CONSTEXPR_AFTER_CXX14
152 return (cur_order == order)?
155 + alpha_s/pi * helper(order, nf, alpha_s, cur_order + 1)
173 inline QCD_CONSTEXPR_AFTER_CXX14
174 double gamma_m(
unsigned order,
int nf,
double alpha_s){
177 return - alpha_s/pi*helper(order, nf, alpha_s, 0);
192 inline QCD_CONSTEXPR_AFTER_CXX14
203 inline QCD_CONSTEXPR_AFTER_CXX14
213 inline QCD_CONSTEXPR_AFTER_CXX14
215 return detail::gamma_m::gamma_m_nf_coeff(order, nfpow);
223 inline QCD_CONSTEXPR_AFTER_CXX14
229 inline QCD_CONSTEXPR_AFTER_CXX14
235 inline QCD_CONSTEXPR_AFTER_CXX14
240 gamma_m_nf_coeff(static_cast<unsigned>(order), static_cast<unsigned>(nfpow));
245 #undef QCD_CONSTEXPR_AFTER_CXX14 QCD_CONSTEXPR_AFTER_CXX14 double gamma_m_nf_coeff(unsigned order, unsigned nfpow)
Coefficient of some power of number of flavours in the mass anomalous dimension.
Definition: gamma_m.hpp:214
Definition: alpha_s.hpp:35
QCD_CONSTEXPR_AFTER_CXX14 double gamma_m(unsigned order, int nf, double alpha_s)
The QCD mass anomalous dimension.
Definition: gamma_m.hpp:174
QCD_CONSTEXPR_AFTER_CXX14 unsigned gamma_m_max_nf_pow(unsigned order)
Highest power of number of flavours in appearing in the mass anomalous dimension. ...
Definition: gamma_m.hpp:204
QCD_CONSTEXPR_AFTER_CXX14 double gamma_m(unsigned order, int nf)
Perturbative coefficients of the QCD mass anomalous dimension.
Definition: gamma_m.hpp:193