The SpinInfo is the base class for the spin information for the spin correlation algorithm. More...

#include <SpinInfo.h>

Inheritance diagram for ThePEG::SpinInfo:

[legend]

Public Types
enum	DevelopedStatus { Undeveloped =0 , Developed =1 , NeedsUpdate =2 , StopUpdate =3 }
	Status for the implementation of spin correlations. More...

Public Types inherited from ThePEG::Pointer::ReferenceCounted
typedef unsigned int	CounterType
	The integer type used for counting.

Public Member Functions
Access the vertices.
void	productionVertex (VertexPtr in) const
	Set the vertex at which the particle was produced.

tcVertexPtr	productionVertex () const
	Get the vertex at which the particle was produced.

void	decayVertex (VertexPtr in) const
	Set the vertex at which the particle decayed or branched.

tcVertexPtr	decayVertex () const
	Get the vertex at which the particle decayed or branched.

Access information about the associated particle.
bool	decayed () const
	Has the particle decayed?

void	decayed (bool b) const
	Set if the particle has decayed.

DevelopedStatus	developed () const
	Return true if the decay matrix required to perform the decays of the siblings of a particle has been calculated.

void	decay (bool recursive=false) const
	Calculate the rho matrix for the decay if not already done.

virtual void	undecay () const
	Calculate the rho matrix for the decay if not already done.

void	develop () const
	Set the developed flag and calculate the D matrix for the decay.

void	needsUpdate () const
	Needs update.

void	stopUpdate () const
	Used for an unstable particle to temporarily stop redevelop and redecay at that particle.

PDT::Spin	iSpin () const
	Return 2s+1 for the particle.

const Lorentz5Momentum &	productionMomentum () const
	Return the momentum of the particle when it was produced.

const Lorentz5Momentum &	currentMomentum () const
	The current momentum of the particle.

bool	timelike () const
	Return true if particle is timelike (rather than spacelike).

int	productionLocation () const
	Access to the locations.

int	decayLocation () const
	Decay Location.

virtual void	rebind (const EventTranslationMap &)
	Rebind to cloned objects.

virtual EIPtr	clone () const
	Standard clone method.

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.

Access the rho and D matrices.
static NoPIOClassDescription< SpinInfo >	initSpinInfo
	Describe a concrete class without persistent data.

static const double	_eps
	A small energy for comparing momenta to check if Lorentz Transformations should be performed.

VertexPtr	_production
	Pointer to the production vertex for the particle.

VertexPtr	_decay
	Pointers to the decay vertex for the particle.

bool	_timelike
	Is this is timelike (true) or spacelike (false ) particle? This is used to decide if the particle is incoming or outgoing at the production vertex.

int	_prodloc
	Location in the hard vertex array at production.

int	_decayloc
	Location in the hard vertex array at decay.

bool	_decayed
	Has the particle been decayed? (I.e.

DevelopedStatus	_developed
	Has the particle been developed? (I.e.

DevelopedStatus	_oldDeveloped
	Has the particle been developed? (I.e.

RhoDMatrix	_rhomatrix
	Storage of the rho matrix.

RhoDMatrix	_Dmatrix
	Storage of the decay matrix.

PDT::Spin	_spin
	The spin of the particle.

Lorentz5Momentum	_productionmomentum
	Momentum of the particle when it was produced.

Lorentz5Momentum	_decaymomentum
	Momentum of the particle when it decayed.

Lorentz5Momentum	_currentmomentum
	Current momentum of the particle.

RhoDMatrix	rhoMatrix () const
	Access the rho matrix.

RhoDMatrix &	rhoMatrix ()
	Access the rho matrix.

RhoDMatrix	DMatrix () const
	Access the D matrix.

RhoDMatrix &	DMatrix ()
	Access the D matrix.

bool	isNear (const Lorentz5Momentum &p)
	Check if momentum is near to the current momentum.

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

void	redevelop () const
	Set the developed flag and calculate the D matrix for the decay, and all decays further up the chain.

void	redecay () const
	Recursively recalulate all the rho matrices from the top of the chain.

Standard constructors and destructors.
	SpinInfo ()
	Default constructor.

	SpinInfo (PDT::Spin s, const Lorentz5Momentum &p=Lorentz5Momentum(), bool time=false)
	Standard Constructor.

	SpinInfo (const SpinInfo &)
	Copy-constructor.

virtual bool	hasPolarization () const
	Returns true if the polarization() has been implemented in a subclass.

virtual DPair	polarization () const
	Return the angles of the polarization vector as a pair of doubles.

virtual void	rebind (const EventTranslationMap &trans)
	Rebind to cloned objects.

virtual EIPtr	clone () const
	Standard clone method.

void	update () const
	Method to handle the delelation.

virtual void	transform (const LorentzMomentum &m, const LorentzRotation &r)
	Perform a lorentz rotation of the spin information.

virtual void	reset ()
	Reset - Undoes any transformations and calls undecay.

static void	Init ()
	Standard Init function.

Additional Inherited Members
Static Public Member Functions inherited from ThePEG::EventInfoBase
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::Pointer::ReferenceCounted
	ReferenceCounted ()
	Default constructor.

	ReferenceCounted (const ReferenceCounted &)
	Copy-constructor.

ReferenceCounted &	operator= (const ReferenceCounted &)
	Assignment.

Detailed Description

The SpinInfo is the base class for the spin information for the spin correlation algorithm.

The implementations for different spin states inherit from this.

The class contains pointers to the vertex where the particle is produced and where it decays, together with methods to set/get these.

There are two flags decayed which store information on the state of the particle.

The decayed() members provides access to the _decay data member which is true if the spin density matrix required to perform the decay of a timelike particle has been calculated (this would be a decay matrix for a spacelike particle.) This is set by the decay() method which calls a method from the production vertex to calculate this matrix. The decay() method should be called by a decayer which uses spin correlation method before it uses the spin density matrix to calculate the matrix element for the decay.

The developed() member provides access to the _developed data member which is true if the decay matrix required to perform the decays of the siblings of a particle has been calculated (this would a spin density matrix for a spacelike particle.) This is set by the developed() method which calls a method from the decay vertex to calculate the matrix. The developed() method is called by a DecayHandler which is capable of performing spin correlations after all the unstable particles produced by a decaying particle are decayed.

Methods are also provided to access the spin density and decay matrices for a particle.

Author: Peter Richardson

Definition at line 58 of file SpinInfo.h.

Member Enumeration Documentation

◆ DevelopedStatus

enum ThePEG::SpinInfo::DevelopedStatus

Status for the implementation of spin correlations.

Enumerator
Undeveloped	Not developed.
Developed	Developed.
NeedsUpdate	Developed but needs recalculating due to some change.
StopUpdate	Stop recalculating at this spin info.

Definition at line 65 of file SpinInfo.h.

Constructor & Destructor Documentation

◆ SpinInfo() [1/2]

ThePEG::SpinInfo::SpinInfo ( )

inline

Default constructor.

Definition at line 79 of file SpinInfo.h.

◆ SpinInfo() [2/2]

ThePEG::SpinInfo::SpinInfo	(	PDT::Spin	s,
		const Lorentz5Momentum &	p = `Lorentz5Momentum()`,
		bool	time = `false`
	)

inline

Standard Constructor.

Parameters

s	the spin.
p	the production momentum.
time	true if the particle is time-like.

Definition at line 90 of file SpinInfo.h.

Member Function Documentation

◆ clone()

virtual EIPtr ThePEG::SpinInfo::clone ( ) const

virtual

Standard clone method.

Reimplemented from ThePEG::EventInfoBase.

Reimplemented in ThePEG::Helicity::FermionSpinInfo, ThePEG::Helicity::Rank3TensorSpinInfo, ThePEG::Helicity::RSFermionSpinInfo, ThePEG::Helicity::ScalarSpinInfo, ThePEG::Helicity::TensorSpinInfo, and ThePEG::Helicity::VectorSpinInfo.

◆ currentMomentum()

const Lorentz5Momentum & ThePEG::SpinInfo::currentMomentum ( ) const

inline

The current momentum of the particle.

Definition at line 278 of file SpinInfo.h.

References _currentmomentum.

Referenced by isNear().

◆ decayed() [1/2]

bool ThePEG::SpinInfo::decayed ( ) const

inline

Has the particle decayed?

Definition at line 221 of file SpinInfo.h.

References _decayed.

◆ decayed() [2/2]

void ThePEG::SpinInfo::decayed ( bool b ) const

inline

Set if the particle has decayed.

Definition at line 226 of file SpinInfo.h.

References _decayed.

◆ decayLocation()

int ThePEG::SpinInfo::decayLocation ( ) const

inline

Decay Location.

Definition at line 300 of file SpinInfo.h.

References _decayloc.

◆ decayVertex() [1/2]

tcVertexPtr ThePEG::SpinInfo::decayVertex ( ) const

inline

Get the vertex at which the particle decayed or branched.

Definition at line 213 of file SpinInfo.h.

References _decay.

◆ decayVertex() [2/2]

void ThePEG::SpinInfo::decayVertex ( VertexPtr in ) const

inline

Set the vertex at which the particle decayed or branched.

Definition at line 189 of file SpinInfo.h.

References _decay, _decayloc, and _timelike.

◆ developed()

DevelopedStatus ThePEG::SpinInfo::developed ( ) const

inline

Return true if the decay matrix required to perform the decays of the siblings of a particle has been calculated.

Definition at line 232 of file SpinInfo.h.

References _developed.

◆ DMatrix() [1/2]

RhoDMatrix & ThePEG::SpinInfo::DMatrix ( )

inline

Access the D matrix.

Definition at line 325 of file SpinInfo.h.

References _Dmatrix.

◆ DMatrix() [2/2]

RhoDMatrix ThePEG::SpinInfo::DMatrix ( ) const

inline

Access the D matrix.

Definition at line 320 of file SpinInfo.h.

References _Dmatrix.

◆ hasPolarization()

virtual bool ThePEG::SpinInfo::hasPolarization ( ) const

inlinevirtual

Returns true if the polarization() has been implemented in a subclass.

This default version returns false.

Definition at line 111 of file SpinInfo.h.

◆ isNear()

bool ThePEG::SpinInfo::isNear ( const Lorentz5Momentum & p )

inline

Check if momentum is near to the current momentum.

Definition at line 333 of file SpinInfo.h.

References _eps, currentMomentum(), and ThePEG::LorentzVector< Value >::isNear().

◆ iSpin()

PDT::Spin ThePEG::SpinInfo::iSpin ( ) const

inline

Return 2s+1 for the particle.

Definition at line 266 of file SpinInfo.h.

References _spin.

◆ needsUpdate()

void ThePEG::SpinInfo::needsUpdate ( ) const

inline

Needs update.

Definition at line 252 of file SpinInfo.h.

References _developed, _oldDeveloped, and NeedsUpdate.

◆ polarization()

virtual DPair ThePEG::SpinInfo::polarization ( ) const

inlinevirtual

Return the angles of the polarization vector as a pair of doubles.

first is the polar angle and second is the azimuth wrt. the particles direction. This default version of the function returns 0,0, and if a subclass implements a proper function it should also implement 'hasPolarization()' to return true.

Definition at line 121 of file SpinInfo.h.

◆ productionLocation()

int ThePEG::SpinInfo::productionLocation ( ) const

inline

Access to the locations.

Production Location

Definition at line 295 of file SpinInfo.h.

References _prodloc.

◆ productionMomentum()

const Lorentz5Momentum & ThePEG::SpinInfo::productionMomentum ( ) const

inline

Return the momentum of the particle when it was produced.

Definition at line 271 of file SpinInfo.h.

References _productionmomentum.

◆ productionVertex() [1/2]

tcVertexPtr ThePEG::SpinInfo::productionVertex ( ) const

inline

Get the vertex at which the particle was produced.

Definition at line 184 of file SpinInfo.h.

References _production.

◆ productionVertex() [2/2]

void ThePEG::SpinInfo::productionVertex ( VertexPtr in ) const

inline

Set the vertex at which the particle was produced.

Definition at line 171 of file SpinInfo.h.

References _prodloc, _production, and _timelike.

◆ rebind()

virtual void ThePEG::SpinInfo::rebind ( const EventTranslationMap & trans )

virtual

Rebind to cloned objects.

If a FermionSpinInfo is cloned together with a whole Event and this has pointers to other event record objects, these should be rebound to their clones in this function.

Reimplemented from ThePEG::EventInfoBase.

◆ reset()

virtual void ThePEG::SpinInfo::reset ( )

inlinevirtual

Reset - Undoes any transformations and calls undecay.

Reimplemented in ThePEG::Helicity::FermionSpinInfo, ThePEG::Helicity::Rank3TensorSpinInfo, ThePEG::Helicity::RSFermionSpinInfo, ThePEG::Helicity::TensorSpinInfo, and ThePEG::Helicity::VectorSpinInfo.

Definition at line 159 of file SpinInfo.h.

References _currentmomentum, and _productionmomentum.

Referenced by ThePEG::Helicity::FermionSpinInfo::reset(), ThePEG::Helicity::Rank3TensorSpinInfo::reset(), ThePEG::Helicity::RSFermionSpinInfo::reset(), ThePEG::Helicity::TensorSpinInfo::reset(), and ThePEG::Helicity::VectorSpinInfo::reset().

◆ rhoMatrix() [1/2]

RhoDMatrix & ThePEG::SpinInfo::rhoMatrix ( )

inline

Access the rho matrix.

Definition at line 315 of file SpinInfo.h.

References _rhomatrix.

◆ rhoMatrix() [2/2]

RhoDMatrix ThePEG::SpinInfo::rhoMatrix ( ) const

inline

Access the rho matrix.

Definition at line 310 of file SpinInfo.h.

References _rhomatrix.

◆ stopUpdate()

void ThePEG::SpinInfo::stopUpdate ( ) const

inline

Used for an unstable particle to temporarily stop redevelop and redecay at that particle.

Definition at line 261 of file SpinInfo.h.

References _developed, and StopUpdate.

◆ timelike()

bool ThePEG::SpinInfo::timelike ( ) const

inline

Return true if particle is timelike (rather than spacelike).

Definition at line 285 of file SpinInfo.h.

References _timelike.

◆ transform()

virtual void ThePEG::SpinInfo::transform	(	const LorentzMomentum &	m,
		const LorentzRotation &	r
	)

inlinevirtual

Perform a lorentz rotation of the spin information.

Reimplemented in ThePEG::Helicity::FermionSpinInfo, ThePEG::Helicity::Rank3TensorSpinInfo, ThePEG::Helicity::RSFermionSpinInfo, ThePEG::Helicity::ScalarSpinInfo, ThePEG::Helicity::TensorSpinInfo, and ThePEG::Helicity::VectorSpinInfo.

Definition at line 151 of file SpinInfo.h.

References _currentmomentum, and ThePEG::Lorentz5Vector< Value >::transform().

◆ undecay()

virtual void ThePEG::SpinInfo::undecay ( ) const

virtual

Calculate the rho matrix for the decay if not already done.

Reimplemented in ThePEG::Helicity::FermionSpinInfo, ThePEG::Helicity::Rank3TensorSpinInfo, ThePEG::Helicity::RSFermionSpinInfo, ThePEG::Helicity::TensorSpinInfo, and ThePEG::Helicity::VectorSpinInfo.

Referenced by ThePEG::Helicity::FermionSpinInfo::undecay(), ThePEG::Helicity::Rank3TensorSpinInfo::undecay(), ThePEG::Helicity::RSFermionSpinInfo::undecay(), ThePEG::Helicity::TensorSpinInfo::undecay(), and ThePEG::Helicity::VectorSpinInfo::undecay().

Member Data Documentation

◆ _currentmomentum

Lorentz5Momentum ThePEG::SpinInfo::_currentmomentum

private

Current momentum of the particle.

Definition at line 437 of file SpinInfo.h.

Referenced by currentMomentum(), reset(), and transform().

◆ _decay

VertexPtr ThePEG::SpinInfo::_decay

mutableprivate

Pointers to the decay vertex for the particle.

Definition at line 372 of file SpinInfo.h.

Referenced by decayVertex().

◆ _decayed

bool ThePEG::SpinInfo::_decayed

mutableprivate

Has the particle been decayed? (I.e.

has the rho matrix for the decay been calculated.)

Definition at line 395 of file SpinInfo.h.

Referenced by decayed().

◆ _decayloc

int ThePEG::SpinInfo::_decayloc

mutableprivate

Location in the hard vertex array at decay.

Definition at line 389 of file SpinInfo.h.

Referenced by decayLocation(), and decayVertex().

◆ _decaymomentum

Lorentz5Momentum ThePEG::SpinInfo::_decaymomentum

mutableprivate

Momentum of the particle when it decayed.

Definition at line 432 of file SpinInfo.h.

◆ _developed

DevelopedStatus ThePEG::SpinInfo::_developed

mutableprivate

Has the particle been developed? (I.e.

has the D matrix encoding the info about the decay been calculated)

Definition at line 401 of file SpinInfo.h.

Referenced by developed(), needsUpdate(), and stopUpdate().

◆ _Dmatrix

RhoDMatrix ThePEG::SpinInfo::_Dmatrix

mutableprivate

Storage of the decay matrix.

Definition at line 417 of file SpinInfo.h.

Referenced by DMatrix().

◆ _eps

const double ThePEG::SpinInfo::_eps

staticprivate

A small energy for comparing momenta to check if Lorentz Transformations should be performed.

Definition at line 443 of file SpinInfo.h.

Referenced by isNear().

◆ _oldDeveloped

DevelopedStatus ThePEG::SpinInfo::_oldDeveloped

mutableprivate

Has the particle been developed? (I.e.

has the D matrix encoding the info about the decay been calculated)

Definition at line 407 of file SpinInfo.h.

Referenced by needsUpdate().

◆ _prodloc

int ThePEG::SpinInfo::_prodloc

mutableprivate

Location in the hard vertex array at production.

Definition at line 384 of file SpinInfo.h.

Referenced by productionLocation(), and productionVertex().

◆ _production

VertexPtr ThePEG::SpinInfo::_production

mutableprivate

Pointer to the production vertex for the particle.

Definition at line 367 of file SpinInfo.h.

Referenced by productionVertex().

◆ _productionmomentum

Lorentz5Momentum ThePEG::SpinInfo::_productionmomentum

private

Momentum of the particle when it was produced.

Definition at line 427 of file SpinInfo.h.

Referenced by productionMomentum(), and reset().

◆ _rhomatrix

RhoDMatrix ThePEG::SpinInfo::_rhomatrix

mutableprivate

Storage of the rho matrix.

Definition at line 412 of file SpinInfo.h.

Referenced by rhoMatrix().

◆ _spin

PDT::Spin ThePEG::SpinInfo::_spin

private

The spin of the particle.

Definition at line 422 of file SpinInfo.h.

Referenced by iSpin().

◆ _timelike

bool ThePEG::SpinInfo::_timelike

private

Is this is timelike (true) or spacelike (false ) particle? This is used to decide if the particle is incoming or outgoing at the production vertex.

Definition at line 379 of file SpinInfo.h.

Referenced by decayVertex(), productionVertex(), and timelike().

◆ initSpinInfo

NoPIOClassDescription<SpinInfo> ThePEG::SpinInfo::initSpinInfo

staticprivate

Describe a concrete class without persistent data.

Definition at line 342 of file SpinInfo.h.

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

SpinInfo.h

Public Types

Public Member Functions

Access the rho and D matrices.

Standard constructors and destructors.

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ DevelopedStatus

Constructor & Destructor Documentation

◆ SpinInfo() [1/2]

◆ SpinInfo() [2/2]

Member Function Documentation

◆ clone()

◆ currentMomentum()

◆ decayed() [1/2]

◆ decayed() [2/2]

◆ decayLocation()

◆ decayVertex() [1/2]

◆ decayVertex() [2/2]

◆ developed()

◆ DMatrix() [1/2]

◆ DMatrix() [2/2]

◆ hasPolarization()

◆ isNear()

◆ iSpin()

◆ needsUpdate()

◆ polarization()

◆ productionLocation()

◆ productionMomentum()

◆ productionVertex() [1/2]

◆ productionVertex() [2/2]

◆ rebind()

◆ reset()

◆ rhoMatrix() [1/2]

◆ rhoMatrix() [2/2]

◆ stopUpdate()

◆ timelike()

◆ transform()

◆ undecay()

Member Data Documentation

◆ _currentmomentum

◆ _decay

◆ _decayed

◆ _decayloc

◆ _decaymomentum

◆ _developed

◆ _Dmatrix

◆ _eps

◆ _oldDeveloped

◆ _prodloc

◆ _production

◆ _productionmomentum

◆ _rhomatrix

◆ _spin

◆ _timelike

◆ initSpinInfo