ThePEG::PartonExtractor Class Reference

The PartonExtractor is a base class defining the interface to objects responsible for extracting partons from particles. More...

#include <PartonExtractor.h>

Inheritance diagram for ThePEG::PartonExtractor:

List of all members.

Public Types

typedef map< cPPtr, PBIPtr > PartonBinInstanceMap

A map of PartonBinInstance objects indexed by the extracted parton.

Public Member Functions

int maxTries () const

The maximum number of attempts allowed when trying to generate remnants.

tcPDFPtr getPDF (tcPDPtr particle) const

Return the PDFBase object to be used for the incoming particle type.

Standard constructors and destructors.

PartonExtractor ()

Default constructor.

virtual ~PartonExtractor ()

Destructor.

Virtual functions which may be overridden in sub-classes.

virtual bool canHandle (const cPDPair &)

Return true if this parton extractor can handle the given types of incoming particles.

virtual PartonPairVec getPartons (Energy maxEnergy, const cPDPair &, const Cuts &) const

Return a vector of possible pairs of parton bins which can be produced within a given maximum total particle-particle invariant mass squared, maxEnergy sBin.

virtual Energy2 newScale ()

May be overriden by sub-classes which have their own oppinion about what scale to use in a hard subprocess.

virtual void colourConnect (tPPtr particle, tPPtr parton, const tPVector &remnants) const

Connect the remnants with the colour lines of the extracted parton.

virtual PBIPair newRemnants (tPPair oldp, tPPair newp, tStepPtr step)

If remnants has already been created for the given parton, remove them from the given step and generate new remnants corresponding to the parton newp and add them to the step.

virtual pair< int, int > nDims (const PBPair &pbins)

Determine the number of random numbers needed to calculate $\hat{s}$ and the product of all densitiy functions.

virtual void prepare (const PBIPair &pbins)

Prepare the given parton bin instances for generating a new event.

virtual bool generateL (const PBIPair &pbins, const double *r1, const double *r2)

Generate $l=\log(1/x)$ for all parton extractions.

virtual Energy2 generateSHat (Energy2 s, const PBIPair &pbins, const double *r1, const double *r2)

Generate the rest of the degrees of freedom to calculate $\hat{s}$ and the product of all densitiy functions.

virtual double fullFn (const PBIPair &pbins, Energy2 scale)

Return the product of all density functions.

virtual void construct (const PBIPair &pbins, tStepPtr step) const

Construct remnants and add them to the step.

virtual void constructRemnants (const PBIPair &pbins, tSubProPtr sub, tStepPtr step) const

Construct remnants for partons created outside of this extractor.

virtual LorentzRotation boostRemnants (PBIPair &bins, LorentzMomentum k1, LorentzMomentum k2, bool side1, bool side2) const

Get boost for hard subsystem and boost remnants.

Access information about the current paron extraction.

tPBIPtr partonBinInstance (tcPPtr) const

Return the corresponding parton bin instance for a given extracted parton.

void select (tXCombPtr newXComb)

Set the XComb object describing the current hard sub-process.

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

virtual void addPartons (tPBPtr incoming, const PDFCuts &cuts, PartonVector &pbins) const

Add parton bins to pbins for the given incoming particle and the specified cuts.

tcPDFPtr noPDF () const

The NoPDF object.

template<typename Iterator>

void findConnect (tColinePtr line, tPPtr parton, bool anti, Iterator first, Iterator last) const

Connect the first (anti) coloured particle in the given range (not equal to parton) and connect it to the colour line.

Functions used by the main virtual functions. Some of

these may be overridden in sub-classes.

virtual void generateL (PartonBinInstance &pb, const double *r)

Used by generateL() for each of the final parton bins.

virtual bool generate (PartonBinInstance &pb, const double *r, Energy2 shat, const Lorentz5Momentum &first)

Used by generateSHat() for each of the final parton bins.

virtual double fullFn (const PartonBinInstance &pb)

Used by the public fullFn() for each of the final parton bins.

virtual void construct (PartonBinInstance &pb, tStepPtr step, bool boost=true) const

Used by the public construct() for each of the final parton bins.

PBIPtr newRemnants (tPBIPtr oldpb, tPPtr newp, const LorentzMomentum &k)

Used by the public newRemnants() for each of the parton bins.

void addNewRemnants (tPBIPtr oldpb, tPBIPtr newpb, tStepPtr step)

Used by the public newRemnants() for each of the parton bins.

virtual void transformRemnants (LorentzMomentum &Ph, LorentzMomentum &Pr, const LorentzMomentum &k, const LorentzMomentum &P) const

Transform remnant momentum.

virtual void constructRemnants (PartonBinInstance &pb, LorentzMomentum &Ph, const LorentzMomentum &k) const

Construct remnants recursively for the parton represented by pb.

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.

Standard Interfaced functions.

virtual void dofinish ()

Finalize this object.

Private Member Functions

PartonExtractor & operator= (const PartonExtractor &)

Private and non-existent assignment operator.

Private Attributes

PartonBinInstanceMap partonBinInstances

The PartonBinInstance's used mapped to the respective partons.

vector< PDFPtr > theSpecialDensities

A list of special PDFBase objects to be used.

PDFPtr theNoPDF

The NoPDF object.

int theMaxTries

The maximum number of tries allowed when trying to produce remnants.

bool flatSHatY

True if this extractor should override the $l$ -generation in the PDFs and generate a flat distribution in $\log(\hat{s})$ and y.

Static Private Attributes

static ClassDescription
< PartonExtractor > initPartonExtractor

Describe a concrete class with persistent data.

Friends

class XComb

XComb is a friend.

Detailed Description

The PartonExtractor is a base class defining the interface to objects responsible for extracting partons from particles.

It is used by a SubProcessHandler which combines one PartonExtractor with a number of MEBase objects which are the used in an XComb in a StandardEventHandler to generate hard sub-processes.

PartonExtractor inherits from the general HandlerBase class and from the LastXCombInfo class to have easy acces to information about the currently chosen hard sub-process.

See also:

The interfaces defined for PartonExtractor.

Definition at line 44 of file PartonExtractor.h.

Member Typedef Documentation

typedef map<cPPtr,PBIPtr> ThePEG::PartonExtractor::PartonBinInstanceMap

A map of PartonBinInstance objects indexed by the extracted parton.

Definition at line 52 of file PartonExtractor.h.

Member Function Documentation

virtual Energy2 ThePEG::PartonExtractor::newScale ( ) [virtual]

May be overriden by sub-classes which have their own oppinion about what scale to use in a hard subprocess.

The default version simply returns the previously selected scale.

virtual PBIPair ThePEG::PartonExtractor::newRemnants	(	tPPair	oldp,
		tPPair	newp,
		tStepPtr	step
	)			`[virtual]`

If remnants has already been created for the given parton, remove them from the given step and generate new remnants corresponding to the parton newp and add them to the step.

The new parton bins are returned.

Exceptions:

Veto

if remnant generation failed for whatever reason.

virtual void ThePEG::PartonExtractor::constructRemnants	(	const PBIPair &	pbins,
		tSubProPtr	sub,
		tStepPtr	step
	)			const `[virtual]`

Construct remnants for partons created outside of this extractor.

Information about the incoming partons should be set in pbins and the hard subprocess should be present in sub. Generated remnants will be added to the step.

Exceptions:

Veto

if remnant generation failed for whatever reason.

virtual LorentzRotation ThePEG::PartonExtractor::boostRemnants	(	PBIPair &	bins,
		LorentzMomentum	k1,
		LorentzMomentum	k2,
		bool	side1,
		bool	side2
	)			const `[virtual]`

Get boost for hard subsystem and boost remnants.

To be called after re-constructing remnants and obtaining new momenta of the partons entering the hard subsystem, but ignoring detailed energy and momentum conservation. Perform boosts of the remnants to conserve energy and momentum and return the boost needed for the hard subsystem. bins contains the current state of the incoming partons, including the momenta obtained after the remnant generation. k1 and k2 contains the momenta of the incoming partons before the remnant generation. If either side has no new remnants, side1 and/or side2 should be false.

tcPDFPtr ThePEG::PartonExtractor::getPDF ( tcPDPtr particle ) const

Return the PDFBase object to be used for the incoming particle type.

If one of theSpecialDensities matches the particle type it is returned, otherwise if particle is a BeamParticleData use the PDFBase object specified there. If also this fails, return a NoPDF object.

virtual void ThePEG::PartonExtractor::generateL	(	PartonBinInstance &	pb,
		const double *	r
	)			`[protected, virtual]`

Used by generateL() for each of the final parton bins.

Direction<0> is set to positive(negative) for the first(second) final bin.

virtual bool ThePEG::PartonExtractor::generate	(	PartonBinInstance &	pb,
		const double *	r,
		Energy2	shat,
		const Lorentz5Momentum &	first
	)			`[protected, virtual]`

Used by generateSHat() for each of the final parton bins.

Direction<0> is set to positive(negative) for the first(second) final bin, pb. Should ask the remnant handler to generate what is needed to construct the extracted parton momentum. r is a pointer to an array of random numbers to be used and shat is the approximate invariant mass squared of the hard system produced by the extracted parton and the primary parton from the other side. first is the momentum of the original incoming particle.

Returns:: false if no remnants could be generated.

virtual void ThePEG::PartonExtractor::construct	(	PartonBinInstance &	pb,
		tStepPtr	step,
		bool	boost = `true`
	)			const `[protected, virtual]`

Used by the public construct() for each of the final parton bins.

If boost is false, no boost is necessary to give the remnants proper momenta.

PBIPtr ThePEG::PartonExtractor::newRemnants	(	tPBIPtr	oldpb,
		tPPtr	newp,
		const LorentzMomentum &	k
	)			`[protected]`

Used by the public newRemnants() for each of the parton bins.

Exceptions:

Veto

if remnant generation failed for whatever reason.

virtual void ThePEG::PartonExtractor::transformRemnants	(	LorentzMomentum &	Ph,
		LorentzMomentum &	Pr,
		const LorentzMomentum &	k,
		const LorentzMomentum &	P
	)			const `[protected, virtual]`

Transform remnant momentum.

Assuming remnants have been generated with momentum Pr without considering energy-momentum conservation, shift the momentum, possibly compensating with the momentum of the hard subsystem, Ph. For information the momentum of the parton entering the hard subsystem from the other side, k, and the momentum of the remnants parent particle , P is given. Note that Direction<0> must be set to determine if the parent particle is to be assumed to go in the positive or negative direction.

virtual void ThePEG::PartonExtractor::constructRemnants	(	PartonBinInstance &	pb,
		LorentzMomentum &	Ph,
		const LorentzMomentum &	k
	)			const `[protected, virtual]`

Construct remnants recursively for the parton represented by pb.

Used by constructRemnants(const PBIPair &, tSubProPtr, tStepPtr). Shift the momentum, Ph, of the hard subsystem to conserve energy and momentum if necessary. The momentum, k, of the parton coming into the hard subsystem from the other side is given for information. Note that Direction<0> must be set to determine if the parent particle is to be assumed to go in the positive or negative direction.

Exceptions:

Veto

if remnant generation failed for whatever reason.

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

Function used to write out object persistently.

Parameters:

os

the persistent output stream written to.

Reimplemented from ThePEG::Interfaced.

void ThePEG::PartonExtractor::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::Interfaced.

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

Make a simple clone of this object.

Returns:: a pointer to the new object.

Implements ThePEG::InterfacedBase.

virtual IBPtr ThePEG::PartonExtractor::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.

virtual void ThePEG::PartonExtractor::dofinish ( ) [protected, virtual]

Finalize this object.

Called in the run phase just after a run has ended. Used eg. to write out statistics.

Reimplemented from ThePEG::InterfacedBase.

Friends And Related Function Documentation

friend class XComb [friend]

XComb is a friend.

Definition at line 47 of file PartonExtractor.h.

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

PartonExtractor.h


Public Types
typedef map< cPPtr, PBIPtr >	PartonBinInstanceMap
	A map of PartonBinInstance objects indexed by the extracted parton.
Public Member Functions
int	maxTries () const
	The maximum number of attempts allowed when trying to generate remnants.
tcPDFPtr	getPDF (tcPDPtr particle) const
	Return the PDFBase object to be used for the incoming particle type.
Standard constructors and destructors.
	PartonExtractor ()
	Default constructor.
virtual	~PartonExtractor ()
	Destructor.
Virtual functions which may be overridden in sub-classes.
virtual bool	canHandle (const cPDPair &)
	Return true if this parton extractor can handle the given types of incoming particles.
virtual PartonPairVec	getPartons (Energy maxEnergy, const cPDPair &, const Cuts &) const
	Return a vector of possible pairs of parton bins which can be produced within a given maximum total particle-particle invariant mass squared, maxEnergy sBin.
virtual Energy2	newScale ()
	May be overriden by sub-classes which have their own oppinion about what scale to use in a hard subprocess.
virtual void	colourConnect (tPPtr particle, tPPtr parton, const tPVector &remnants) const
	Connect the remnants with the colour lines of the extracted parton.
virtual PBIPair	newRemnants (tPPair oldp, tPPair newp, tStepPtr step)
	If remnants has already been created for the given parton, remove them from the given step and generate new remnants corresponding to the parton newp and add them to the step.
virtual pair< int, int >	nDims (const PBPair &pbins)
	Determine the number of random numbers needed to calculate $\hat{s}$ and the product of all densitiy functions.
virtual void	prepare (const PBIPair &pbins)
	Prepare the given parton bin instances for generating a new event.
virtual bool	generateL (const PBIPair &pbins, const double r1, const double r2)
	Generate $l=\log(1/x)$ for all parton extractions.
virtual Energy2	generateSHat (Energy2 s, const PBIPair &pbins, const double r1, const double r2)
	Generate the rest of the degrees of freedom to calculate $\hat{s}$ and the product of all densitiy functions.
virtual double	fullFn (const PBIPair &pbins, Energy2 scale)
	Return the product of all density functions.
virtual void	construct (const PBIPair &pbins, tStepPtr step) const
	Construct remnants and add them to the step.
virtual void	constructRemnants (const PBIPair &pbins, tSubProPtr sub, tStepPtr step) const
	Construct remnants for partons created outside of this extractor.
virtual LorentzRotation	boostRemnants (PBIPair &bins, LorentzMomentum k1, LorentzMomentum k2, bool side1, bool side2) const
	Get boost for hard subsystem and boost remnants.
Access information about the current paron extraction.
tPBIPtr	partonBinInstance (tcPPtr) const
	Return the corresponding parton bin instance for a given extracted parton.
void	select (tXCombPtr newXComb)
	Set the XComb object describing the current hard sub-process.
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
virtual void	addPartons (tPBPtr incoming, const PDFCuts &cuts, PartonVector &pbins) const
	Add parton bins to pbins for the given incoming particle and the specified cuts.
tcPDFPtr	noPDF () const
	The NoPDF object.
template<typename Iterator>
void	findConnect (tColinePtr line, tPPtr parton, bool anti, Iterator first, Iterator last) const
	Connect the first (anti) coloured particle in the given range (not equal to parton) and connect it to the colour line.
Functions used by the main virtual functions. Some of
these may be overridden in sub-classes.
virtual void	generateL (PartonBinInstance &pb, const double *r)
	Used by generateL() for each of the final parton bins.
virtual bool	generate (PartonBinInstance &pb, const double *r, Energy2 shat, const Lorentz5Momentum &first)
	Used by generateSHat() for each of the final parton bins.
virtual double	fullFn (const PartonBinInstance &pb)
	Used by the public fullFn() for each of the final parton bins.
virtual void	construct (PartonBinInstance &pb, tStepPtr step, bool boost=true) const
	Used by the public construct() for each of the final parton bins.
PBIPtr	newRemnants (tPBIPtr oldpb, tPPtr newp, const LorentzMomentum &k)
	Used by the public newRemnants() for each of the parton bins.
void	addNewRemnants (tPBIPtr oldpb, tPBIPtr newpb, tStepPtr step)
	Used by the public newRemnants() for each of the parton bins.
virtual void	transformRemnants (LorentzMomentum &Ph, LorentzMomentum &Pr, const LorentzMomentum &k, const LorentzMomentum &P) const
	Transform remnant momentum.
virtual void	constructRemnants (PartonBinInstance &pb, LorentzMomentum &Ph, const LorentzMomentum &k) const
	Construct remnants recursively for the parton represented by pb.
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.
Standard Interfaced functions.
virtual void	dofinish ()
	Finalize this object.
Private Member Functions
PartonExtractor &	operator= (const PartonExtractor &)
	Private and non-existent assignment operator.
Private Attributes
PartonBinInstanceMap	partonBinInstances
	The PartonBinInstance's used mapped to the respective partons.
vector< PDFPtr >	theSpecialDensities
	A list of special PDFBase objects to be used.
PDFPtr	theNoPDF
	The NoPDF object.
int	theMaxTries
	The maximum number of tries allowed when trying to produce remnants.
bool	flatSHatY
	True if this extractor should override the -generation in the PDFs and generate a flat distribution in $\log(\hat{s})$ and y.
Static Private Attributes
static ClassDescription < PartonExtractor >	initPartonExtractor
	Describe a concrete class with persistent data.
Friends
class	XComb
	XComb is a friend.