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LHAPDF  6.4.0
LHAPDF::AlphaS_Analytic Class Reference

Calculate alpha_s(Q2) by an analytic approximation. More...

#include <AlphaS.h>

Inheritance diagram for LHAPDF::AlphaS_Analytic:

Public Member Functions

std::string type () const
 Implementation type of this solver.
double alphasQ2 (double q2) const
 Calculate alphaS(Q2)
int numFlavorsQ2 (double q2) const
 Analytic has its own numFlavorsQ2 which respects the min/max nf set by the Lambdas.
void setLambda (unsigned int i, double lambda)
 Set lambda_i (for i = flavour number)
- Public Member Functions inherited from LHAPDF::AlphaS
 AlphaS ()
 Base class constructor for default param setup.
virtual ~AlphaS ()
double alphasQ (double q) const
 Calculate alphaS(Q)
int numFlavorsQ (double q) const
 Calculate the number of active flavours at energy scale Q.
double quarkMass (int id) const
 Get a quark mass by PDG code.
void setQuarkMass (int id, double value)
 Set quark masses by PDG code. More...
double quarkThreshold (int id) const
 Get a flavor scale threshold by PDG code. More...
void setQuarkThreshold (int id, double value)
 Set a flavor threshold by PDG code (= quark masses by default) More...
int orderQCD ()
void setOrderQCD (int order)
 Set the order of QCD (expressed as number of loops) More...
void setMZ (double mz)
 Set the Z mass used in this alpha_s. More...
void setAlphaSMZ (double alphas)
 Set the alpha_s(MZ) used in this alpha_s. More...
void setMassReference (double mref)
 Set the Z mass used in this alpha_s. More...
void setAlphaSReference (double alphas)
 Set the alpha_s(MZ) used in this alpha_s. More...
void setFlavorScheme (FlavorScheme scheme, int nf=-1)
 Set flavor scheme of alpha_s solver.
FlavorScheme flavorScheme () const
 Get flavor scheme.

Private Member Functions

double _lambdaQCD (int nf) const
 Get lambdaQCD for nf.
void _setFlavors ()
 Recalculate min/max flavors in case lambdas have changed.

Private Attributes

std::map< int, double > _lambdas
 LambdaQCD values.
int _nfmax
 Max number of flavors.
int _nfmin
 Min number of flavors.

Additional Inherited Members

- Public Types inherited from LHAPDF::AlphaS
enum  FlavorScheme { FIXED, VARIABLE }
 Enum of flavor schemes.
- Protected Member Functions inherited from LHAPDF::AlphaS
double _beta (int i, int nf) const
std::vector< double > _betas (int nf) const
- Protected Attributes inherited from LHAPDF::AlphaS
int _qcdorder
 Order of QCD evolution (expressed as number of loops)
double _mz
 Mass of the Z boson in GeV.
double _alphas_mz
 Value of alpha_s(MZ)
double _mreference
 Reference mass in GeV.
double _alphas_reference
 Value of alpha_s(reference mass)
bool _customref
 Decides whether to use custom reference values or fall back on MZ/AlphaS_MZ.
std::map< int, double > _quarkmasses
std::map< int, double > _flavorthresholds
FlavorScheme _flavorscheme
 The flavor scheme in use.
int _fixflav
 The allowed numbers of flavours in a fixed scheme.

Detailed Description

Calculate alpha_s(Q2) by an analytic approximation.


The documentation for this class was generated from the following file: