The Amplitude class is the abstract base class for all the classes representing complex amplitudes associated with either a hard 2 \(\rightarrow\) N subprocess or a decay 1 \(\rightarrow\) N process. More...

#include <Amplitude.h>

Inheritance diagram for ThePEG::Amplitude:

[legend]

Private Member Functions
Main virtual functions to be overridden by sub-classes.
virtual Complex	value (const tcPDVector &particles, const vector< Lorentz5Momentum > &momenta, const vector< int > &helicities)=0
	Return the amplitude.

virtual Complex	overestimateValue (const tcPDVector &particles, const vector< Lorentz5Momentum > &momenta, const vector< int > &helicities)
	Return an overestimated amplitude.

Alternative interface to main virtual functions.
static AbstractNoPIOClassDescription< Amplitude >	initAmplitude
	Describe an abstract base class with persistent data.

Complex	value (const PVector &particles, const vector< int > &helicities)
	Return the amplitude.

Complex	overestimateValue (const PVector &particles, const vector< int > &helicities)
	Return an overestimated amplitude.

static void	Init ()
	Standard Init function used to initialize the interfaces.

Amplitude &	operator= (const Amplitude &)=delete
	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 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

The Amplitude class is the abstract base class for all the classes representing complex amplitudes associated with either a hard 2 \(\rightarrow\) N subprocess or a decay 1 \(\rightarrow\) N process.

The returned value should be dimensionless suitable scaled by the total invariant mass squared (shat), which is always computable from the specified momenta of the particles in the vertex. Notice that the amplitude for splitting 1 \(\rightarrow\) N processes is instead represented in other classes (derived from the SplitFun class).

See also: The interfaces defined for Amplitude.

Definition at line 34 of file Amplitude.h.

Member Function Documentation

◆ overestimateValue() [1/2]

Complex ThePEG::Amplitude::overestimateValue	(	const PVector &	particles,
		const vector< int > &	helicities
	)

private

Return an overestimated amplitude.

Calls overestimateValue(const tcPDVector &, const vector<Lorentz5Momentum> &, const vector<int> &)

◆ overestimateValue() [2/2]

virtual Complex ThePEG::Amplitude::overestimateValue	(	const tcPDVector &	particles,
		const vector< Lorentz5Momentum > &	momenta,
		const vector< int > &	helicities
	)

privatevirtual

Return an overestimated amplitude.

Same as value(const tcPDVector &, const vector<Lorentz5Momentum> &, const vector<int> &), but it provides an overestimate of the complex amplitude, that is: abs( overestimaValue() ) >= abs(value()) The default definition just returns value(), but it can be overriden by derived classes.

◆ value() [1/2]

Complex ThePEG::Amplitude::value	(	const PVector &	particles,
		const vector< int > &	helicities
	)

private

Return the amplitude.

Calls value(const tcPDVector &, const vector<Lorentz5Momentum> &, const vector<int> &) and should not be overridden.

◆ value() [2/2]

virtual Complex ThePEG::Amplitude::value	(	const tcPDVector &	particles,
		const vector< Lorentz5Momentum > &	momenta,
		const vector< int > &	helicities
	)

privatepure virtual

Return the amplitude.

Given the ParticleData objects in particles, their momenta and helicities of all the particles in the vertex, return the complex amplitude. The convention is the order of the vectors is that first there is the incoming particle(s) and then the outgoing ones. For the helicities, the convention is to number them starting from 0 (no negative values, because they are used as vector indeces), for example, for a massive particle of spin S, 0 <= helicity <= 2*S. The returned value should be dimensionless suitable scaled by the total invariant mass squared ( \(\hat{s}\)), which is always computable from the specified momenta of the particles in the vertex.

Member Data Documentation

◆ initAmplitude

AbstractNoPIOClassDescription<Amplitude> ThePEG::Amplitude::initAmplitude

static

Describe an abstract base class with persistent data.

Definition at line 98 of file Amplitude.h.

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

Amplitude.h

Private Member Functions

Alternative interface to main virtual functions.

Additional Inherited Members