Decayer is an abstract base class to specify objects modelling the decay of a particle. More...

#include <Decayer.h>

Inheritance diagram for ThePEG::Decayer:

[legend]

Classes
struct	DecayFailure
	Exception class used if something goes wrong in DecayParticle(). More...

Functions used by the persistent I/O system.
static AbstractNoPIOClassDescription< Decayer >	initDecayer
	The static object used to initialize the description of this class.

Ptr< Amplitude >::pointer	theAmplitude
	A possible null pointer to an amplitude associated with this matrix element.

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 interfaces.

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

Virtual functions to be overridden in sub-classes.
virtual bool	accept (const DecayMode &dm) const =0
	Check if this decayer can perfom the decay specified by the given decay mode.

virtual bool	needsFullStep () const
	Return true if this Decayer need to access the full current step when a particle is decayed.

virtual ParticleVector	decay (const DecayMode &dm, const Particle &p) const =0
	Perform a decay for a given DecayMode and a given Particle instance.

virtual ParticleVector	decay (const DecayMode &dm, const Particle &p, Step &step) const
	Perform a decay for a given DecayMode and a given Particle instance.

virtual double	brat (const DecayMode &dm, const ParticleData &pd, double oldbrat) const
	Calculate branching ratio.

virtual double	brat (const DecayMode &dm, const Particle &p, double oldbrat) const
	Calculate branching ratio.

virtual ParticleVector	getChildren (const DecayMode &dm, const Particle &parent) const
	Produce the children.

virtual void	finalBoost (const Particle &parent, const ParticleVector &children) const
	Boost the decay products.

virtual void	setScales (const Particle &parent, const ParticleVector &children) const
	Set the scales.

Ptr< Amplitude >::pointer	amplitude () const
	Return an amplitude associated with this decay matrix element.

static ParticleVector	DecayParticle (tPPtr parent, Step &step, long maxtry=1000)
	Static function to administer the decay of a particle.

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 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.

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

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

Decayer is an abstract base class to specify objects modelling the decay of a particle.

See also: The interfaces defined for Decayer.; ParticleData; DecayMode

Definition at line 29 of file Decayer.h.

Member Function Documentation

◆ accept()

virtual bool ThePEG::Decayer::accept ( const DecayMode & dm ) const

pure virtual

Check if this decayer can perfom the decay specified by the given decay mode.

Parameters

dm	the DecayMode describing the decay.

Returns: true if this decayer can handle the given mode, otherwise false.

Implemented in ThePEG::ColourPairDecayer, ThePEG::DalitzDecayer, ThePEG::DummyDecayer, ThePEG::FlatDecayer, ThePEG::OmegaPhi3PiDecayer, ThePEG::Onium3GDecayer, ThePEG::QuarksToHadronsDecayer, ThePEG::RemnantDecayer, ThePEG::SimpleBaryonRemnantDecayer, ThePEG::Tau2HadronsDecayer, ThePEG::V2PPDecayer, and ThePEG::WeakToHadronsDecayer.

◆ amplitude()

Ptr< Amplitude >::pointer ThePEG::Decayer::amplitude ( ) const

inline

Return an amplitude associated with this decay matrix element.

May return null.

Definition at line 127 of file Decayer.h.

References theAmplitude.

◆ brat() [1/2]

virtual double ThePEG::Decayer::brat	(	const DecayMode &	dm,
		const Particle &	p,
		double	oldbrat
	)		const

virtual

Calculate branching ratio.

If this model has any oppinions on the decay rate for a given decay mode dm, for a given particle p, this method may be overriden to return this oppinion. oldbrat is the branching ratio specified in the DecayMode or by asking the WidthGenerator of p.

Reimplemented in ThePEG::DummyDecayer.

◆ brat() [2/2]

virtual double ThePEG::Decayer::brat	(	const DecayMode &	dm,
		const ParticleData &	pd,
		double	oldbrat
	)		const

virtual

Calculate branching ratio.

If this model has any oppinions on the decay rate for a given decay mode dm, for a given particle type pd, this method may be overriden to return this oppinion. oldbrat is the branching ratio specified in the DecayMode or by asking the WidthGenerator of pd.

Reimplemented in ThePEG::DummyDecayer.

◆ decay() [1/2]

virtual ParticleVector ThePEG::Decayer::decay	(	const DecayMode &	dm,
		const Particle &	p
	)		const

pure virtual

Perform a decay for a given DecayMode and a given Particle instance.

Parameters

dm	the DecayMode describing the decay.
p	the Particle instance to be decayed.

Returns: a ParticleVector containing the decay products.

Implemented in ThePEG::DalitzDecayer, ThePEG::DummyDecayer, ThePEG::FlatDecayer, ThePEG::Onium3GDecayer, ThePEG::QuarksToHadronsDecayer, ThePEG::RemnantDecayer, and ThePEG::V2PPDecayer.

◆ decay() [2/2]

virtual ParticleVector ThePEG::Decayer::decay	(	const DecayMode &	dm,
		const Particle &	p,
		Step &	step
	)		const

virtual

Perform a decay for a given DecayMode and a given Particle instance.

This version allows the decaying particle to borrow energy/momentum from its sublings in the current step. This will be called by the standard DecayHandler if the needsFullStep() function returns true.

Parameters

dm	the DecayMode describing the decay.
p	the Particle instance to be decayed.
step	the current step in which to find possible siblings to shuffle energy with.

Returns: a ParticleVector containing the decay products.

Reimplemented in ThePEG::SimpleBaryonRemnantDecayer, and ThePEG::RemnantDecayer.

◆ DecayParticle()

static ParticleVector ThePEG::Decayer::DecayParticle	(	tPPtr	parent,
		Step &	step,
		long	maxtry = `1000`
	)

static

Static function to administer the decay of a particle.

The children are properly added to the particle and to the given step. Maximum maxtry attempts to decay the particle is performed.

Returns: the produced children.

◆ finalBoost()

virtual void ThePEG::Decayer::finalBoost	(	const Particle &	parent,
		const ParticleVector &	children
	)		const

virtual

Boost the decay products.

Can be used by sub-classes to perform the final boost back from the parents cms. This default version does just that.

◆ getChildren()

virtual ParticleVector ThePEG::Decayer::getChildren	(	const DecayMode &	dm,
		const Particle &	parent
	)		const

virtual

Produce the children.

Can be used by sub-class decay() functions to produce instances of the children. This default implementation just calls the produceProducts() of the specified decay products in DecayMode object, dm.

Reimplemented in ThePEG::ColourPairDecayer.

◆ needsFullStep()

virtual bool ThePEG::Decayer::needsFullStep ( ) const

virtual

Return true if this Decayer need to access the full current step when a particle is decayed.

If true is returned the standard Decay Handler will call the decay(const DecayMode&,const Particle&,Step&) function rather than the decay(const DecayMode&,const Particle&) function.

Reimplemented in ThePEG::RemnantDecayer.

◆ persistentInput()

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

Function used to write out object persistently.

Parameters

os	the persistent output stream written to.

◆ setScales()

virtual void ThePEG::Decayer::setScales	(	const Particle &	parent,
		const ParticleVector &	children
	)		const

virtual

Set the scales.

Can be used by sub classes to set the production scale of the children. This default version sets the scale to the parents mass.

Member Data Documentation

◆ initDecayer

AbstractNoPIOClassDescription<Decayer> ThePEG::Decayer::initDecayer

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 174 of file Decayer.h.

◆ theAmplitude

Ptr<Amplitude>::pointer ThePEG::Decayer::theAmplitude

private

A possible null pointer to an amplitude associated with this matrix element.

Definition at line 185 of file Decayer.h.

Referenced by amplitude().

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

Decayer.h

Classes

Functions used by the persistent I/O system.

Virtual functions to be overridden in sub-classes.

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ accept()

◆ amplitude()

◆ brat() [1/2]

◆ brat() [2/2]

◆ decay() [1/2]

◆ decay() [2/2]

◆ DecayParticle()

◆ finalBoost()

◆ getChildren()

◆ needsFullStep()

◆ persistentInput()

◆ persistentOutput()

◆ setScales()

Member Data Documentation

◆ initDecayer

◆ theAmplitude