ePDF::AlphaQED Class Reference

The "Alpha QED" class. More...

#include <alphaem.h>

Public Member Functions
	AlphaQED (YAML::Node const &config)
	The "Alpha QED" constructor. More...
	AlphaQED (std::string const &method, std::string const &po, double const &aref, double const &Qref, int const &NL, int const &NF)
	The "Alpha QED" constructor. More...
double	Evolve (double const &Q) const
	Function that return the evolved alpha according to the chose method. More...
double	operator() (double const &Q) const
	Operator to return alpha at the scale Q. More...
double	EvolveAnalytic (double const &Q) const
	Function that return the alpha analytically. More...
double	EvolveNumerical (double const &Q) const
	Function that return the alpha numerically. More...
double	Beta0QED () const
	The beta function coefficients. More...
double	Beta1QED () const
bool	IsFixed () const
	Whether alpha is fixed or runs. More...
double	FBetaQED (double const &alpha) const
	The beta function. More...

Private Attributes
const std::string	m_method
	Evolution method. More...
const std::string	m_po
	Perturbative order. More...
const double	m_aref
	Reference value of alpha. More...
const double	m_Qref
	Reference scale. More...
const int	m_NL
	Number of active charged leptons. More...
const int	m_NF
	Number of active quarks. More...
std::vector< double >	m_sumch2
	Sum of the electric charges squared. More...
std::vector< double >	m_sumch4
	Sum of the electric charges to the fourth. More...
Parameter of numerical integration
const int	m_nstep = 10
const double	m_sxth = 0.166666666666666

Detailed Description

The "Alpha QED" class.

Constructor & Destructor Documentation

AlphaQED() [1/2]

ePDF::AlphaQED::AlphaQED

(

YAML::Node const &

config

)

The "Alpha QED" constructor.

Parameters

config

the YAML:Node with the parameters

AlphaQED() [2/2]

ePDF::AlphaQED::AlphaQED	(	std::string const &	method,
		std::string const &	po,
		double const &	aref,
		double const &	Qref,
		int const &	NL,
		int const &	NF
	)

The "Alpha QED" constructor.

Parameters

method	the solution method
po	the perturbative order
aref	the reference value of alpha
Qref	the reference scale
NL	the number of active charged leptons
NF	the number of active quarks

Member Function Documentation

Beta0QED()

double ePDF::AlphaQED::Beta0QED

(

)

const

The beta function coefficients.

Beta1QED()

double ePDF::AlphaQED::Beta1QED

(

)

const

Evolve()

double ePDF::AlphaQED::Evolve

(

double const &

Q

)

const

Function that return the evolved alpha according to the chose method.

Parameters

Q	final scale

Note

This functions returns alpha / (4pi)

EvolveAnalytic()

double ePDF::AlphaQED::EvolveAnalytic

(

double const &

Q

)

const

Function that return the alpha analytically.

Parameters

Q	final scale

EvolveNumerical()

double ePDF::AlphaQED::EvolveNumerical

(

double const &

Q

)

const

Function that return the alpha numerically.

Parameters

Q	final scale

FBetaQED()

double ePDF::AlphaQED::FBetaQED

(

double const &

alpha

)

const

The beta function.

Parameters

alpha

the value of alpha to be used to compute the beta function

IsFixed()

bool ePDF::AlphaQED::IsFixed

(

)

const

Whether alpha is fixed or runs.

operator()()

double ePDF::AlphaQED::operator() ( double const &  Q ) const

inline

Operator to return alpha at the scale Q.

Parameters

Q	final scale

Member Data Documentation

m_aref

const double ePDF::AlphaQED::m_aref

private

Reference value of alpha.

m_method

const std::string ePDF::AlphaQED::m_method

private

Evolution method.

m_NF

const int ePDF::AlphaQED::m_NF

private

Number of active quarks.

m_NL

const int ePDF::AlphaQED::m_NL

private

Number of active charged leptons.

m_nstep

const int ePDF::AlphaQED::m_nstep = 10

private

m_po

const std::string ePDF::AlphaQED::m_po

private

Perturbative order.

m_Qref

const double ePDF::AlphaQED::m_Qref

private

Reference scale.

m_sumch2

std::vector<double> ePDF::AlphaQED::m_sumch2

private

Initial value:

= { 0.0, 1.0/9.0, 5.0/9.0, 2.0/3.0,
                                     10.0/9.0, 11.0/9.0, 5.0/3.0
                                   }

Sum of the electric charges squared.

m_sumch4

std::vector<double> ePDF::AlphaQED::m_sumch4

private

Initial value:

= { 0.0, 1.0/81.0, 17.0/81.0, 18.0/81.0,
                                     34.0/81.0, 35.0/81.0, 51.0/81.0
                                   }

Sum of the electric charges to the fourth.

m_sxth

const double ePDF::AlphaQED::m_sxth = 0.166666666666666

private

---

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

• /Users/vbertone/Codes/ePDF/inc/ePDF/alphaem.h