PDFBase is the base class for implementing parton density functions for particles with sub-structure. More...

#include <PDFBase.h>

Inheritance diagram for ThePEG::PDFBase:

[legend]

Public Member Functions
Standard constructors and destructors.
	PDFBase ()
	Default constructor.

	PDFBase (const PDFBase &)
	Copy-constructor.

virtual	~PDFBase ()
	Destructor.

Virtual functions to be overridden by sub-classes.
virtual bool	canHandleParticle (tcPDPtr particle) const =0
	Return true if this PDF can handle the extraction of partons from the given particle.

virtual bool	canHandle (tcPDPtr particle) const
	Return true if canHandleParticle() and if the corresponding method for remnantHandler() returns true for the given particle.

virtual bool	hasPoleIn1 (tcPDPtr particle, tcPDPtr parton) const
	Return true if this PDF has a pole at $x=1$ for the given particle and parton.

virtual cPDVector	partons (tcPDPtr particle) const =0
	Return the partons which this PDF may extract from the given particle.

virtual double	xfl (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double l, Energy2 particleScale=ZERO) const
	The density.

virtual double	xfx (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double x, double eps=0.0, Energy2 particleScale=ZERO) const
	The density.

virtual double	xfvl (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double l, Energy2 particleScale=ZERO) const
	The valence density.

virtual double	xfvx (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double x, double eps=0.0, Energy2 particleScale=ZERO) const
	The valence density.

virtual double	xfsl (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double l, Energy2 particleScale=ZERO) const
	The sea density.

virtual double	xfsx (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double x, double eps=0.0, Energy2 particleScale=ZERO) const
	The sea density.

virtual double	flattenL (tcPDPtr particle, tcPDPtr parton, const PDFCuts &cut, double z, double &jacobian) const
	Generate a momentum fraction.

virtual double	flattenScale (tcPDPtr particle, tcPDPtr parton, const PDFCuts &cut, double l, double z, double &jacobian) const
	Generate scale (as a fraction of the maximum scale).

tcRemHPtr	remnantHandler () const
	Pointer to the remnant handler to handle remnant when extracting partons according to these densities.

Public Member Functions inherited from ThePEG::HandlerBaseT< UseRandom >
virtual	~HandlerBaseT ()
	Destructor.

double	rnd () const
	Return a simple flat random number in the range ]0,1[.

double	rnd (double xu) const
	Return a simple flat random number in the range ]0,xu[.

double	rnd (double xl, double xu) const
	Return a simple flat random number in the range ]xl,xu[.

bool	rndbool () const
	Return true with 50% probability.

bool	rndbool (double p) const
	Return a true with probability p.

bool	rndbool (double p1, double p2) const
	Return a true with probability p1/(p1+p2).

int	rndsign (double p1, double p2, double p3) const
	Return -1, 0, or 1 with relative probabilities p1, p2, p3.

int	rnd2 (double p0, double p1) const
	Return an integer $i$ with probability p $i$/(p0+p1).

int	rnd3 (double p0, double p1, double p2) const
	Return an integer $i$ with probability p $i$/(p0+p1+p2).

int	rnd4 (double p0, double p1, double p2, double p3) const
	Return an integer/ $i$ with probability p $i$(p0+p1+p2+p3).

long	irnd (long xu=2) const
	Return a simple flat random integrer number in the range [0,xu[.

long	irnd (long xl, long xu) const
	Return a simple flat random integrer number in the range [xl,xu[.

const StandardModelBase &	SM () const
	Return a reference to the object containing the standard model parameters for this run.

tSMPtr	standardModel () const
	Return a pointer to the object containing the standard model parameters for this run.

Public Member Functions inherited from ThePEG::Interfaced
virtual	~Interfaced ()
	Empty virtual destructor.

virtual bool	defaultInit ()
	Functions which are to be used during the actual event generation, after the setup is complete.

PPtr	getParticle (PID) const
	Create a new Particle instance given a id number.

PDPtr	getParticleData (PID) const
	Return a pointer to the ParticleData object corresponding to the given id number.

bool	used () const
	Returns true if this object has actally been used.

void	useMe () const
	Should be called to indicate that this object has actually been used.

tEGPtr	generator () const
	Return a pointer to the EventGenerator controlling the run.

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.

Public Member Functions inherited from ThePEG::InterfacedBase
virtual	~InterfacedBase ()
	The virtual (empty) destructor;.

string	fullName () const
	Returns the full name of this object including its path, e.g.

string	name () const
	Returns the name of this object, without the path.

string	path () const
	Returns the path to this object including the trailing '/'.

string	comment () const
	Returns a comment assigned to this object.

void	setup (istream &is)
	Read setup info from a standard istream is.

void	update ()
	Calls the doupdate() function with recursion prevention.

void	init ()
	Calls the doinit() function with recursion prevention.

virtual bool	preInitialize () const
	Return true if this object needs to be initialized before all other objects (except those for which this function also returns true).

void	initrun ()
	Calls the doinitrun() function with recursion prevention.

void	finish ()
	Calls the dofinish() function with recursion prevention.

void	touch ()
	This function should be called every time something in this object has changed in a way that a sanity check with update() is needed.

void	reset ()
	Set the state of this object to uninitialized.

void	clear ()
	Calls reset() and unTouch().

InitState	state () const
	Return the state of initialization of this object.

bool	locked () const
	Return true if the BaseRepository is not allowed to change the state of this object.

bool	touched () const
	Return true if the state of this object has been changed since the last call to update().

virtual IBPtr	fullclone () const
	Return a full clone of this object possibly doing things to the clone to make it sane.

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.

virtual void	debugme () const
	Print out debugging information for this object on std::cerr.

Public Member Functions inherited from ThePEG::Base
virtual	~Base ()
	The virtual destructor.

void	debug () const
	Print out debugging information for this object on std::cerr.

virtual void	debugme () const
	Print out debugging information for this object on std::cerr.

Public Member Functions inherited from ThePEG::Pointer::ReferenceCounted
CounterType	referenceCount () const
	Return the reference count.

Public Member Functions inherited from ThePEG::Named
	Named (const string &newName=string())
	Constructor with name.

	Named (const Named &)=default
	Explicit default copy-constructor (too avoid compiler warnings)

const string &	name () const
	Return name.

bool	operator== (const Named &other) const
	Test for equality.

bool	operator< (const Named &other) const
	Lexicographical comparison.

Standard Interfaced functions.
enum	RangeException { rangeFreeze , rangeZero , rangeThrow }
	Indicate how to deal with x and Q2 which are out of range. More...

RemHPtr	theRemnantHandler
	A remnant handler which can generate remnants for the parton extracted withfor this PDF.

RangeException	rangeException
	Indicate to subclasses how to deal with x and Q2 which are out of range.

static AbstractClassDescription< PDFBase >	initPDFBase
	The static object used to initialize the description of this class.

virtual void	doinit ()
	Initialize this object after the setup phase before saving an EventGenerator to disk.

PDFBase &	operator= (const PDFBase &)=delete
	Private and non-existent assignment operator.

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 void	Init ()
	Standard Init function used to initialize the interface.

Additional Inherited Members
Public Types inherited from ThePEG::InterfacedBase
enum	InitState { initializing = -1 , uninitialized = 0 , initialized = 1 , runready = 2 }
	Enumeration reflecting the state of an InterfacedBase object. More...

Public Types inherited from ThePEG::Pointer::ReferenceCounted
typedef unsigned int	CounterType
	The integer type used for counting.

Static Public Member Functions inherited from ThePEG::HandlerBase
static void	Init ()
	Standard Init function used to initialize the interface.

Static Public Member Functions inherited from ThePEG::Interfaced
static void	Init ()
	Standard Init function.

Static Public Member Functions inherited from ThePEG::InterfacedBase
static void	Init ()
	Standard Init function.

Static Public Member Functions inherited from ThePEG::Base
static void	Init ()
	The standard Init function used to initialize the interfaces.

Public Attributes inherited from ThePEG::Pointer::ReferenceCounted
const unsigned long	uniqueId
	The unique ID.

Protected Member Functions inherited from ThePEG::Interfaced
void	reporeg (IBPtr object, string name) const
	Register the given object in the Repository with the given name in a subdirectory with the same name as this object.

template<typename PtrT >
bool	setDefaultReference (PtrT &ptr, string classname, string objectname)
	If the pointer, ptr, to an object is not set, create an object of class classname and register it with the Repository with the given objectname in a sib-directory with the same name as this object.

	Interfaced ()
	Protected default constructor.

	Interfaced (const string &newName)
	Protected constructor taking a name as argument.

	Interfaced (const Interfaced &i)
	Protected copy-constructor.

void	setGenerator (tEGPtr generator)
	Protected function to reset the generator pointer, required for automatic decayer generation in Herwig++ BSM models.

Protected Member Functions inherited from ThePEG::InterfacedBase
virtual void	readSetup (istream &is)
	Read setup info from a standard istream is.

virtual void	doupdate ()
	Check sanity of the object during the setup phase.

virtual void	doinitrun ()
	Initialize this object.

virtual void	dofinish ()
	Finalize this object.

virtual IVector	getReferences ()
	Return a vector of all pointers to Interfaced objects used in this object.

virtual void	rebind (const TranslationMap &)
	Rebind pointer to other Interfaced objects.

virtual IBPtr	clone () const =0
	Return a simple clone of this object.

	InterfacedBase ()
	Protected default constructor.

	InterfacedBase (string newName)
	Protected constructor with the name given as argument.

	InterfacedBase (const InterfacedBase &i)
	Protected copy-constructor.

Protected Member Functions inherited from ThePEG::Pointer::ReferenceCounted
	ReferenceCounted ()
	Default constructor.

	ReferenceCounted (const ReferenceCounted &)
	Copy-constructor.

ReferenceCounted &	operator= (const ReferenceCounted &)
	Assignment.

Protected Member Functions inherited from ThePEG::Named
const Named &	operator= (const Named &other)
	Assignment.

const string &	name (const string &newName)
	Set new name.

Static Protected Member Functions inherited from ThePEG::Interfaced
static void	registerRepository (IBPtr)
	Register an Interfaced object with the Repository.

static void	registerRepository (IBPtr, string newName)
	Register an Interfaced object with the Repository, giving it a name.

Detailed Description

PDFBase is the base class for implementing parton density functions for particles with sub-structure.

A number of of virtual methods are defined which should be overridden by sub-classes.

It is essential that either xfx or xfl is overidden to avoid infinite recursive function calls.

A PDFBase object can be assigned to a BeamParticleData object and/or to a PartonExtractor object. A PDFBase has a pointer to a RemnantHandler object which should be capable of generating remnants for all partons which may be extracted by the PDF.

See also: The interfaces defined for PDFBase.; BeamParticleData; PartonExtractor; RemnantHandler; PDFCuts

Definition at line 40 of file PDFBase.h.

Member Enumeration Documentation

◆ RangeException

enum ThePEG::PDFBase::RangeException

protected

Indicate how to deal with x and Q2 which are out of range.

Enumerator

rangeZero

‍Freeze the value of the PDF outside the limits.

rangeThrow

‍Set the PDF to zero outside the limits.

‍Throw an exception if outside the limits.

Definition at line 246 of file PDFBase.h.

Member Function Documentation

◆ canHandle()

virtual bool ThePEG::PDFBase::canHandle ( tcPDPtr particle ) const

virtual

Return true if canHandleParticle() and if the corresponding method for remnantHandler() returns true for the given particle.

Reimplemented in ThePEG::NoPDF.

◆ canHandleParticle()

virtual bool ThePEG::PDFBase::canHandleParticle ( tcPDPtr particle ) const

pure virtual

Return true if this PDF can handle the extraction of partons from the given particle.

Implemented in ThePEG::BudnevPDF, ThePEG::GRVBase, ThePEG::LeptonLeptonPDF, ThePEG::LHAPDF, ThePEG::NoPDF, ThePEG::NuclearPhotonPDF, and ThePEG::WeizsackerWilliamsPDF.

◆ doinit()

virtual void ThePEG::PDFBase::doinit ( )

protectedvirtual

Initialize this object after the setup phase before saving an EventGenerator to disk.

Exceptions

InitException if object could not be initialized properly.

Reimplemented from ThePEG::InterfacedBase.

Reimplemented in ThePEG::LHAPDF.

◆ flattenL()

virtual double ThePEG::PDFBase::flattenL	(	tcPDPtr	particle,
		tcPDPtr	parton,
		const PDFCuts &	cut,
		double	z,
		double &	jacobian
	)		const

virtual

Generate a momentum fraction.

If the PDF contains strange peaks which can be difficult to handle, this function may be overwritten to return an appropriate $l=\log(1/x)$ for a z uniformly distributed in ]0,1[. Also the jacobobian of the $l\rightarrow z$ variable transformation must in the function multiply the jacobian argument. The default version will simply use the function $l(z) = l_{\min} + z*(l_{\max}-l_{\min})$ (where the limits are set by cut).

Reimplemented in ThePEG::LeptonLeptonPDF, ThePEG::BudnevPDF, ThePEG::NuclearPhotonPDF, and ThePEG::WeizsackerWilliamsPDF.

◆ flattenScale()

virtual double ThePEG::PDFBase::flattenScale	(	tcPDPtr	particle,
		tcPDPtr	parton,
		const PDFCuts &	cut,
		double	l,
		double	z,
		double &	jacobian
	)		const

virtual

Generate scale (as a fraction of the maximum scale).

If the PDF contains strange peaks which can be difficult to handle, this function may be overwritten to return an appropriate scale $Q^2/Q^2_{\max}$ for a z uniformly distributed in ]0,1[. Also the jacobobian of the $Q^2/Q^2_{\max}\rightarrow z$ variable transformation must multiply the jacobian argument. The default version will simply use the function $Q^2/Q^2_{\max} = (Q^2_{\max}/Q^2_{\min})^(z-1)$ or, if $Q^2_{\min}$ is zero, $Q^2/Q^2_{\max} = z$ (where the limits are set by cut).

Reimplemented in ThePEG::BudnevPDF, ThePEG::NuclearPhotonPDF, and ThePEG::WeizsackerWilliamsPDF.

◆ hasPoleIn1()

virtual bool ThePEG::PDFBase::hasPoleIn1	(	tcPDPtr	particle,
		tcPDPtr	parton
	)		const

virtual

Return true if this PDF has a pole at $x=1$ for the given particle and parton.

This default version of the function returns false.

Reimplemented in ThePEG::LeptonLeptonPDF, and ThePEG::NoPDF.

◆ partons()

virtual cPDVector ThePEG::PDFBase::partons ( tcPDPtr particle ) const

pure virtual

Return the partons which this PDF may extract from the given particle.

Implemented in ThePEG::GRVBase, ThePEG::LeptonLeptonPDF, ThePEG::NoPDF, ThePEG::BudnevPDF, ThePEG::LHAPDF, ThePEG::NuclearPhotonPDF, and ThePEG::WeizsackerWilliamsPDF.

◆ persistentInput()

void ThePEG::PDFBase::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.

◆ persistentOutput()

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

Function used to write out object persistently.

Parameters

os	the persistent output stream written to.

◆ remnantHandler()

tcRemHPtr ThePEG::PDFBase::remnantHandler ( ) const

inline

Pointer to the remnant handler to handle remnant when extracting partons according to these densities.

Definition at line 196 of file PDFBase.h.

References theRemnantHandler.

◆ xfl()

virtual double ThePEG::PDFBase::xfl	(	tcPDPtr	particle,
		tcPDPtr	parton,
		Energy2	partonScale,
		double	l,
		Energy2	particleScale = `ZERO`
	)		const

virtual

The density.

Return the pdf for the given parton inside the given particle for the virtuality partonScale and logarithmic momentum fraction l $(l=\log(1/x)$. The particle is assumed to have a virtuality particleScale.

Reimplemented in ThePEG::GRVBase, ThePEG::NuclearPhotonPDF, ThePEG::BudnevPDF, ThePEG::LeptonLeptonPDF, ThePEG::NoPDF, and ThePEG::WeizsackerWilliamsPDF.

◆ xfsl()

virtual double ThePEG::PDFBase::xfsl	(	tcPDPtr	particle,
		tcPDPtr	parton,
		Energy2	partonScale,
		double	l,
		Energy2	particleScale = `ZERO`
	)		const

virtual

The sea density.

Return the pdf for the given cvalence parton inside the given particle for the virtuality partonScale and logarithmic momentum fraction l $(l=\log(1/x)$. The particle is assumed to have a virtuality particleScale. If not overidden by a sub class this implementation will assume that the difference between a quark and anti-quark distribution is due do valense quarks.

◆ xfsx()

virtual double ThePEG::PDFBase::xfsx	(	tcPDPtr	particle,
		tcPDPtr	parton,
		Energy2	partonScale,
		double	x,
		double	eps = `0.0`,
		Energy2	particleScale = `ZERO`
	)		const

virtual

The sea density.

Return the pdf for the given cvalence parton inside the given particle for the virtuality partonScale and momentum fraction x. The particle is assumed to have a virtuality particleScale. If not overidden by a sub class this implementation will assume that the difference between a quark and anti-quark distribution is due do valense quarks.

Reimplemented in ThePEG::LHAPDF.

◆ xfvl()

virtual double ThePEG::PDFBase::xfvl	(	tcPDPtr	particle,
		tcPDPtr	parton,
		Energy2	partonScale,
		double	l,
		Energy2	particleScale = `ZERO`
	)		const

virtual

The valence density.

Return the pdf for the given cvalence parton inside the given particle for the virtuality partonScale and logarithmic momentum fraction l $(l=\log(1/x)$. The particle is assumed to have a virtuality particleScale. If not overidden by a sub class this implementation will assume that the difference between a quark and anti-quark distribution is due do valense quarks, but return zero for anything else.

Reimplemented in ThePEG::GRVBase, ThePEG::NuclearPhotonPDF, ThePEG::BudnevPDF, ThePEG::LeptonLeptonPDF, ThePEG::LHAPDF, and ThePEG::WeizsackerWilliamsPDF.

◆ xfvx()

virtual double ThePEG::PDFBase::xfvx	(	tcPDPtr	particle,
		tcPDPtr	parton,
		Energy2	partonScale,
		double	x,
		double	eps = `0.0`,
		Energy2	particleScale = `ZERO`
	)		const

virtual

The valence density.

Return the pdf for the given cvalence parton inside the given particle for the virtuality partonScale and momentum fraction x. The particle is assumed to have a virtuality particleScale. If not overidden by a sub class this implementation will assume that the difference between a quark and anti-quark distribution is due do valense quarks, but return zero for anything else.

Reimplemented in ThePEG::LeptonLeptonPDF, and ThePEG::LHAPDF.

◆ xfx()

virtual double ThePEG::PDFBase::xfx	(	tcPDPtr	particle,
		tcPDPtr	parton,
		Energy2	partonScale,
		double	x,
		double	eps = `0.0`,
		Energy2	particleScale = `ZERO`
	)		const

virtual

The density.

Return the pdf for the given parton inside the given particle for the virtuality partonScale and momentum fraction x. The particle is assumed to have a virtuality particleScale.

Reimplemented in ThePEG::LHAPDF.

Member Data Documentation

◆ initPDFBase

AbstractClassDescription<PDFBase> ThePEG::PDFBase::initPDFBase

staticprivate

The static object used to initialize the description of this class.

Indicates that this is an abstract class with persistent data.

Definition at line 265 of file PDFBase.h.

◆ rangeException

RangeException ThePEG::PDFBase::rangeException

protected

Indicate to subclasses how to deal with x and Q2 which are out of range.

Definition at line 256 of file PDFBase.h.

◆ theRemnantHandler

RemHPtr ThePEG::PDFBase::theRemnantHandler

protected

A remnant handler which can generate remnants for the parton extracted withfor this PDF.

Definition at line 239 of file PDFBase.h.

Referenced by remnantHandler().

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

PDFBase.h

Public Member Functions

Standard Interfaced functions.

Functions used by the persistent I/O system.

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ RangeException

Member Function Documentation

◆ canHandle()

◆ canHandleParticle()

◆ doinit()

◆ flattenL()

◆ flattenScale()

◆ hasPoleIn1()

◆ partons()

◆ persistentInput()

◆ persistentOutput()

◆ remnantHandler()

◆ xfl()

◆ xfsl()

◆ xfsx()

◆ xfvl()

◆ xfvx()

◆ xfx()

Member Data Documentation

◆ initPDFBase

◆ rangeException

◆ theRemnantHandler