ThePEG::O1AlphaS Class Reference

O1AlphaS inherits from AlphaSBase and implements the leading order running QCD coupling. More...

#include <O1AlphaS.h>

Inheritance diagram for ThePEG::O1AlphaS:

List of all members.

Public Member Functions

unsigned int getMaxFlav () const

Return the maximum number of active flavours.

Standard constructors and destructors.

O1AlphaS ()

Default constructor.

Virtual functions mandated by the sub-class.

virtual double value (Energy2 scale, const StandardModelBase &) const

The $\alpha_S$ .

virtual unsigned int nloops () const

Return the number of loops contributing to the running this coupling.

virtual vector< Energy2 > flavourThresholds () const

Return the flavour thresholds used.

virtual vector< Energy > LambdaQCDs () const

Return the $\Lambda_{QCD}$ used for different numbers of active flavours.

Functions used by the persistent I/O system.

void persistentOutput (PersistentOStream &os) const

Function used to write out object persistently.

void persistentInput (PersistentIStream &is, int version)

Function used to read in object persistently.

Static Public Member Functions

static void Init ()

Standard Init function used to initialize the interface.

Protected Member Functions

Clone Methods.

virtual IBPtr clone () const

Make a simple clone of this object.

virtual IBPtr fullclone () const

Make a clone of this object, possibly modifying the cloned object to make it sane.

Private Member Functions

O1AlphaS & operator= (const O1AlphaS &)

Private and non-existent assignment operator.

Private Attributes

Energy theLambdaQCD

The $\Lambda_{QCD}$ for the number of flavours specified by theLambdaFlavour.

unsigned int theLambdaFlavour

The number of flavours for which theLambdaQCD is given.

unsigned int theMaxFlav

The maximum number of active flavours.

Energy Q0

The scale below which $\alpha_S$ is frozen.

Static Private Attributes

static ClassDescription< O1AlphaS > initO1AlphaS

Describe a concrete class with persistent data.

Detailed Description

O1AlphaS inherits from AlphaSBase and implements the leading order running QCD coupling.

The value is determined by a $\Lambda_{QCD}$ parameter at a given number of flavours. Optionally the coupling can be frozen under some minimum scale to avoid divergencies or negative couplings.

See also:: The interfaces defined for O1AlphaS.

Definition at line 27 of file O1AlphaS.h.

Member Function Documentation

virtual double ThePEG::O1AlphaS::value	(	Energy2	scale,
		const StandardModelBase &
	)			const `[virtual]`

The $\alpha_S$ .

Return the QCD coupling for a given scale using the given standard model object sm.

Implements ThePEG::RunningCoupling.

virtual vector<Energy2> ThePEG::O1AlphaS::flavourThresholds ( ) const [virtual]

Return the flavour thresholds used.

The returned vector contains (in position i) the scales when the active number of flavours changes from i to i+1.

Implements ThePEG::AlphaSBase.

void ThePEG::O1AlphaS::persistentOutput ( PersistentOStream & os ) const

Function used to write out object persistently.

Parameters:

os

the persistent output stream written to.

Reimplemented from ThePEG::AlphaSBase.

void ThePEG::O1AlphaS::persistentInput	(	PersistentIStream &	is,
		int	version
	)

Function used to read in object persistently.

Parameters:

	is	the persistent input stream read from.
	version	the version number of the object when written.

Reimplemented from ThePEG::AlphaSBase.

virtual IBPtr ThePEG::O1AlphaS::clone ( ) const [protected, virtual]

Make a simple clone of this object.

Returns:: a pointer to the new object.

Implements ThePEG::InterfacedBase.

virtual IBPtr ThePEG::O1AlphaS::fullclone ( ) const [protected, virtual]

Make a clone of this object, possibly modifying the cloned object to make it sane.

Returns:: a pointer to the new object.

Reimplemented from ThePEG::InterfacedBase.

Member Data Documentation

Energy ThePEG::O1AlphaS::theLambdaQCD [private]

The $\Lambda_{QCD}$ for the number of flavours specified by theLambdaFlavour.

Other $\Lambda_{QCD}$ values for other numbers of active flavours are calculated from flavourThresholds() using a continuity requirement.

Definition at line 125 of file O1AlphaS.h.

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

O1AlphaS.h


Public Member Functions
unsigned int	getMaxFlav () const
	Return the maximum number of active flavours.
Standard constructors and destructors.
	O1AlphaS ()
	Default constructor.
Virtual functions mandated by the sub-class.
virtual double	value (Energy2 scale, const StandardModelBase &) const
	The $\alpha_S$ .
virtual unsigned int	nloops () const
	Return the number of loops contributing to the running this coupling.
virtual vector< Energy2 >	flavourThresholds () const
	Return the flavour thresholds used.
virtual vector< Energy >	LambdaQCDs () const
	Return the $\Lambda_{QCD}$ used for different numbers of active flavours.
Functions used by the persistent I/O system.
void	persistentOutput (PersistentOStream &os) const
	Function used to write out object persistently.
void	persistentInput (PersistentIStream &is, int version)
	Function used to read in object persistently.
Static Public Member Functions
static void	Init ()
	Standard Init function used to initialize the interface.
Protected Member Functions
Clone Methods.
virtual IBPtr	clone () const
	Make a simple clone of this object.
virtual IBPtr	fullclone () const
	Make a clone of this object, possibly modifying the cloned object to make it sane.
Private Member Functions
O1AlphaS &	operator= (const O1AlphaS &)
	Private and non-existent assignment operator.
Private Attributes
Energy	theLambdaQCD
	The $\Lambda_{QCD}$ for the number of flavours specified by theLambdaFlavour.
unsigned int	theLambdaFlavour
	The number of flavours for which theLambdaQCD is given.
unsigned int	theMaxFlav
	The maximum number of active flavours.
Energy	Q0
	The scale below which $\alpha_S$ is frozen.
Static Private Attributes
static ClassDescription< O1AlphaS >	initO1AlphaS
	Describe a concrete class with persistent data.