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ThePEG  2.1.0
ThePEG::PDFBase Class Referenceabstract

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

#include <PDFBase.h>

Inheritance diagram for ThePEG::PDFBase:

Public Member Functions

tcRemHPtr remnantHandler () const
 Pointer to the remnant handler to handle remnant when extracting partons according to these densities.
 
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. More...
 
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. More...
 
virtual double xfx (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double x, double eps=0.0, Energy2 particleScale=ZERO) const
 The density. More...
 
virtual double xfvl (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double l, Energy2 particleScale=ZERO) const
 The valence density. More...
 
virtual double xfvx (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double x, double eps=0.0, Energy2 particleScale=ZERO) const
 The valence density. More...
 
virtual double xfsl (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double l, Energy2 particleScale=ZERO) const
 The sea density. More...
 
virtual double xfsx (tcPDPtr particle, tcPDPtr parton, Energy2 partonScale, double x, double eps=0.0, Energy2 particleScale=ZERO) const
 The sea density. More...
 
virtual double flattenL (tcPDPtr particle, tcPDPtr parton, const PDFCuts &cut, double z, double &jacobian) const
 Generate a momentum fraction. More...
 
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). More...
 
Functions used by the persistent I/O system.
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently. More...
 
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently. More...
 
- Public Member Functions inherited from ThePEG::HandlerBaseT< UseRandom >
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 StandardModelBaseSM () 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.
 
virtual ~HandlerBaseT ()
 Destructor.
 
- 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. More...
 
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. More...
 
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently. More...
 
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently. More...
 
- 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. More...
 
string name () const
 Returns the name of this object, without the path.
 
string path () const
 Returns the path to this object including the trailing '/'. More...
 
string comment () const
 Returns a comment assigned to this object.
 
void setup (istream &is)
 Read setup info from a standard istream is. More...
 
virtual IBPtr fullclone () const
 Return a full clone of this object possibly doing things to the clone to make it sane.
 
virtual void debugme () const
 Print out debugging information for this object on std::cerr. More...
 
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). More...
 
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().
 
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently. More...
 
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently. More...
 
- 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. More...
 
- 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.
 
const string & name () const
 Return name.
 
bool operator== (const Named &other) const
 Test for equality.
 
bool operator< (const Named &other) const
 Lexicographical comparison.
 

Static Public Member Functions

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

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< PDFBaseinitPDFBase
 The static object used to initialize the description of this class. More...
 
virtual void doinit ()
 Initialize this object after the setup phase before saving an EventGenerator to disk. More...
 
PDFBaseoperator= (const PDFBase &)
 Private and non-existent assignment operator.
 

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.
 
- Public Attributes inherited from ThePEG::Pointer::ReferenceCounted
const unsigned long uniqueId
 The unique ID. More...
 
- 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. More...
 
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 IBPtr clone () const =0
 Return a simple clone of this object. More...
 
 InterfacedBase ()
 Protected default constructor.
 
 InterfacedBase (string newName)
 Protected constructor with the name given as argument.
 
 InterfacedBase (const InterfacedBase &i)
 Protected copy-constructor.
 
virtual void readSetup (istream &is)
 Read setup info from a standard istream is. More...
 
virtual void doupdate ()
 Check sanity of the object during the setup phase. More...
 
virtual void doinitrun ()
 Initialize this object. More...
 
virtual void dofinish ()
 Finalize this object. More...
 
virtual IVector getReferences ()
 Return a vector of all pointers to Interfaced objects used in this object. More...
 
virtual void rebind (const TranslationMap &)
 Rebind pointer to other Interfaced objects. More...
 
- Protected Member Functions inherited from ThePEG::Pointer::ReferenceCounted
 ReferenceCounted ()
 Default constructor.
 
 ReferenceCounted (const ReferenceCounted &)
 Copy-constructor.
 
ReferenceCountedoperator= (const ReferenceCounted &)
 Assignment.
 
- Protected Member Functions inherited from ThePEG::Named
const Namedoperator= (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

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

◆ doinit()

virtual void ThePEG::PDFBase::doinit ( )
protectedvirtual

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

Exceptions
InitExceptionif object could not be initialized properly.

Reimplemented from ThePEG::InterfacedBase.

Reimplemented in ThePEG::LHAPDF.

Referenced by remnantHandler().

◆ 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::BudnevPDF, ThePEG::WeizsackerWilliamsPDF, and ThePEG::LeptonLeptonPDF.

◆ 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, 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::NoPDF, and ThePEG::LeptonLeptonPDF.

◆ persistentInput()

void ThePEG::PDFBase::persistentInput ( PersistentIStream is,
int  version 
)

Function used to read in object persistently.

Parameters
isthe persistent input stream read from.
versionthe version number of the object when written.

Referenced by remnantHandler().

◆ persistentOutput()

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

Function used to write out object persistently.

Parameters
osthe persistent output stream written to.

Referenced by remnantHandler().

◆ 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::NoPDF, ThePEG::LeptonLeptonPDF, ThePEG::BudnevPDF, 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::LHAPDF, ThePEG::GRVBase, ThePEG::LeptonLeptonPDF, ThePEG::BudnevPDF, 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::LHAPDF, and ThePEG::LeptonLeptonPDF.

◆ 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.


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