The CascadeHandler is the base class of all handlers implementing perturbative partonic cascade models. More...

#include <CascadeHandler.h>

Inheritance diagram for ThePEG::CascadeHandler:

[legend]

Public Member Functions
virtual void	cascade ()=0
	The main function to be overwritten by sub-classes. More...

virtual double	reweightCKKW (int minMult, int maxMult)
	The CascadeHandler can be used inside the process generation to do so-called CKKW reweighting of the hard sub-process. More...

Standard constructors and destructors.
virtual	~CascadeHandler ()
	The destructor.

Virtual functions required by the StepHandler class.
virtual void	handle (EventHandler &eh, const tPVector &tagged, const Hint &hint)
	The main function called by the EventHandler class to perform a step. More...

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

tEHPtr	eventHandler () const
	Get a pointer to the EventHandler which made the last call to handle().

void	eventHandler (tEHPtr)
	Set a pointer to the EventHandler which made the last call to handle().

tStepPtr	newStep ()
	Return a pointer to a new step. More...

tStepPtr	currentStep ()
	If a new step has been created, return it, otherwise return the current step from the eventHandler().

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 with probability p /(p0+p1).

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

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

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.

	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.

Public Member Functions inherited from ThePEG::LastXCombInfo<>
const XComb &	lastXComb () const
	Return a reference to the last selected XComb.

tXCPtr	lastXCombPtr () const
	Return a pointer to the last selected XComb.

const XComb &	lastHeadXComb () const
	If the last selected XComb object belongs to a group of XComb's return a reference to the head XComb object for this group.

tXCPtr	lastHeadXCombPtr () const
	If the last selected XComb object belongs to a group of XComb's return a pointer to the head XComb object for this group.

const EventHandler &	lastEventHandler () const
	Return a reference to the currently used EventHandler.

tPExtrPtr	lastExtractor () const
	A pointer to the currently used parton extractor.

PDFT	pdf (tcPPtr parton) const
	Return the parton density used to extract the given parton. More...

const Cuts &	lastCuts () const
	A reference to the currently used kinematical cuts.

tCutsPtr	lastCutsPtr () const
	A pointer to the currently used kinematical cuts.

const PPair &	lastParticles () const
	Return the pair of incoming parton instances.

Energy2	lastS () const
	The last generated total energy squared of the incoming particles.

const PPair &	lastPartons () const
	Return the pair of incoming parton instances.

Energy2	lastSHat () const
	The last used interval in total parton-parton energy squared.

double	lastTau () const
	Return lastSHat()/lastS().

double	lastY () const
	The generated rapidity of the hard scattering sub-system.

double	lastP1 () const
	Log of one over the momentum fraction of the first incoming particle w.r.t. More...

double	lastP2 () const
	Log of one over the momentum fraction of the second incoming particle w.r.t. More...

double	lastL1 () const
	Log of one over the first incoming parton momentum fraction w.r.t. More...

double	lastL2 () const
	Log of one over the second incoming parton momentum fraction w.r.t. More...

double	lastX1 () const
	The first incoming parton momentum fraction w.r.t. More...

double	lastX2 () const
	The second incoming parton momentum fraction w.r.t. More...

double	lastE1 () const
	Return 1-lastX1() to highest possible precision for x $\rightarrow$ 1.

double	lastE2 () const
	Return 1-lastX2() to highest possible precision for x $\rightarrow$ 1.

double	lastFL1L2 () const
	The product of the parton density functions at the last generated phase-space point.

Energy2	lastScale () const
	The chosen scale of the hard scattering.

double	lastAlphaS () const
	Get the $\alpha_S$ used in the hard scattering. More...

double	lastAlphaEM () const
	Get the $\alpha_{EM}$ used in the hard scattering. More...

const vector< Lorentz5Momentum > &	meMomenta () const
	Return the momenta of the incoming and outgoing partons to be used by the matrix element object, in the order specified by the TreeDiagram objects given by the matrix element.

double	lastME2 () const
	Return the matrix element squared as calculated for the last phase space point. More...

double	lastPreweight () const
	Return the last preweight factor.

double	jacobian () const
	Get the last jacobian obtained when generating the kinematics for the call to dSigHatDR.

CrossSection	lastMECrossSection () const
	Return the partonic cross section as calculated for the last phase space point. More...

double	lastMEPDFWeight () const
	Return the PDF weight as calculated for the last phase space point, if the matrix element does supply PDF weights. More...

double	lastMECouplings () const
	Return the coupling weight as calculated for the last phase space point.

tSubProPtr	subProcess () const
	Return the SubProcess object corresponding to the last generated sub-process.

const cPDVector &	mePartonData () const
	Return the incoming and outgoing parton types to be used by the matrix element object, in the order specified by the TreeDiagram objects given by the matrix element.

Static Public Member Functions
static void	Init ()
	Standard Init function used to initialize the interface.

Static Public Member Functions inherited from ThePEG::StepHandler
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...

Private Member Functions
CascadeHandler &	operator= (const CascadeHandler &)=delete
	Private and non-existent assignment operator.

Private Attributes
const tPVector *	theTagged
	Store the tagged argument given to handle().

const Hint *	theHint
	Store the Hint arguments given to handle().

pair< PDF, PDF >	thePDFs
	The pdfs used to extract the incoming partons.

Static Private Attributes
static bool	theDidRunCascade
	If there are multiple cascade calls, this flag tells if cascade was called before.

static AbstractNoPIOClassDescription< CascadeHandler >	initCascadeHandler
	The static object used to initialize the description of this class. More...

Access information stored by the handle() function.
const tPVector &	tagged () const
	Return the vector of tagged particles which should be showered. More...

const Hint &	hint () const
	Return the int provided in the current call to handle().

const PDF &	firstPDF () const
	Return references to the PDF used by the first incoming particle.

const PDF &	secondPDF () const
	Return references to the PDF used by the first incoming particle.

const pair< PDF, PDF > &	pdfs () const
	Return references to the currently used PDF's.

void	resetPDFs (const pair< tcPDFPtr, tcPDFPtr > &pdfpair)
	Set alternative PDFBase objects to be used for cascade.

void	resetPDFs (const pair< tcPDFPtr, tcPDFPtr > &pdfpair, PBPair ppair)
	Set alternative PDFBase objects to be used for cascade.

void	setXComb (tXCombPtr xc)
	Set the XComb object with information about the sub-process generation.

virtual bool	isReshuffling () const
	Return true, if this cascade handler will perform reshuffling from hard process masses.

bool	didRunCascade () const
	For multiple cascade calls, this flag tells if cascade was called before.

static void	setDidRunCascade (bool c)
	Set the flag to inform if prior cascades had been called.

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 Types inherited from ThePEG::LastXCombInfo<>
typedef ThePEG::Ptr< XComb >::pointer	XCPtr
	Alias for a reference counted pointer to XC . More...

typedef ThePEG::Ptr< XComb >::const_pointer	cXCPtr
	Alias for a reference counted pointer to a const XC . More...

typedef ThePEG::Ptr< XComb >::transient_pointer	tXCPtr
	Alias for a transient pointer to XC . More...

typedef ThePEG::Ptr< XComb >::transient_const_pointer	tcXCPtr
	Alias for a transient pointer to a const XC . More...

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

Protected Member Functions inherited from ThePEG::StepHandler
void	createNewStep ()
	Use the collision handler to create a new step.

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

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.

Protected Attributes inherited from ThePEG::LastXCombInfo<>
XCPtr	theLastXComb
	The pointer to the last selected XComb.

Detailed Description

The CascadeHandler is the base class of all handlers implementing perturbative partonic cascade models.

It is derived from the more general StepHandler class, and implements the handle() function to do some standard initialization before calling the main cascade() function.

See also: The interfaces defined for CascadeHandler.; StepHandler; EventHandler; SubProcessHandler

Definition at line 33 of file CascadeHandler.h.

Member Function Documentation

◆ cascade()

virtual void ThePEG::CascadeHandler::cascade ( )

pure virtual

The main function to be overwritten by sub-classes.

It is called by handle() after storing some information which is then available through simple access functions.

◆ handle()

virtual void ThePEG::CascadeHandler::handle	(	EventHandler &	eh,
		const tPVector &	tagged,
		const Hint &	hint
	)

virtual

The main function called by the EventHandler class to perform a step.

Parameters

eh	the EventHandler in charge of the Event generation.
tagged	if not empty these are the only particles which should be considered by the StepHandler.
hint	a Hint object with possible information from previously performed steps.

Exceptions

Veto	if the StepHandler requires the current step to be discarded.
Stop	if the generation of the current Event should be stopped after this call.
Exception	if something goes wrong.

Implements ThePEG::StepHandler.

◆ reweightCKKW()

virtual double ThePEG::CascadeHandler::reweightCKKW	(	int	minMult,
		int	maxMult
	)

virtual

The CascadeHandler can be used inside the process generation to do so-called CKKW reweighting of the hard sub-process.

In this case this function is called after information about the sub-process is made available through the LastXCombInfo base class. Only the function belonging to the primary CascadeHandler for the event to be generated is called. Sub-classes may implement it to give a suitable weight in return. The CascadeHandler may store information about the generated sub-process to be used in the subsequent cascade. It is however not guaranteed that the reweightCKKW() will have been called for the subprocess handed to the handle() function. This default implementation of the function simply return one. The current sub-process is mixed together with other processes with a multiplicity of outgoing particles between minMult and maxMult.

◆ tagged()

const tPVector& ThePEG::CascadeHandler::tagged ( ) const

inline

Return the vector of tagged particles which should be showered.

It the vector is empty, the patons from the current sub-process is supposed to be showered.

Definition at line 102 of file CascadeHandler.h.

References theTagged.

Member Data Documentation

◆ initCascadeHandler

AbstractNoPIOClassDescription<CascadeHandler> ThePEG::CascadeHandler::initCascadeHandler

staticprivate

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

Indicates that this is an abstract class without persistent data.

Definition at line 196 of file CascadeHandler.h.

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

CascadeHandler.h

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Access information stored by the handle() function.

Additional Inherited Members