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LHAPDF  6.2.0
LHAPDF::AlphaS_Analytic Class Reference

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

#include <AlphaS.h>

Inheritance diagram for LHAPDF::AlphaS_Analytic:
LHAPDF::AlphaS

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 ()
 Destructor.
 
void setFlavorScheme (FlavorScheme scheme, int nf=-1)
 Set flavor scheme of alpha_s solver.
 
FlavorScheme flavorScheme () const
 Get flavor scheme.
 
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...
 

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.

Examples:
/tests/testalphas.cc.

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