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 ()
	Destructor.
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.
double	quarkThreshold (int id) const
	Get a flavor scale threshold by PDG code.
void	setQuarkThreshold (int id, double value)
	Set a flavor threshold by PDG code (= quark masses by default).
int	orderQCD ()
void	setOrderQCD (int order)
	Set the order of QCD (expressed as number of loops).
void	setMZ (double mz)
	Set the Z mass used in this alpha_s.
void	setAlphaSMZ (double alphas)
	Set the alpha_s(MZ) used in this alpha_s.
void	setMassReference (double mref)
	Set the Z mass used in this alpha_s.
void	setAlphaSReference (double alphas)
	Set the alpha_s(MZ) used in this alpha_s.
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.

Examples

/tests/testalphas.cc.

Member Function Documentation

alphasQ2()

double LHAPDF::AlphaS_Analytic::alphasQ2 ( double q2 ) const

virtual

Calculate alphaS(Q2).

Implements LHAPDF::AlphaS.

numFlavorsQ2()

int LHAPDF::AlphaS_Analytic::numFlavorsQ2 ( double q2 ) const

virtual

Analytic has its own numFlavorsQ2 which respects the min/max nf set by the Lambdas.

Reimplemented from LHAPDF::AlphaS.

setLambda()

void LHAPDF::AlphaS_Analytic::setLambda ( unsigned int i, double lambda )

virtual

Set lambda_i (for i = flavour number).

Reimplemented from LHAPDF::AlphaS.

Examples

/tests/testalphas.cc.

type()

std::string LHAPDF::AlphaS_Analytic::type ( ) const

inlinevirtual

Implementation type of this solver.

Implements LHAPDF::AlphaS.

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

• /builds/hepcedar/lhapdf/include/LHAPDF/AlphaS.h