The FermionSpinInfo class inherits from the SpinInfo class and implements the storage of the basis vectors for a spin-1/2 particle. More...

#include <FermionSpinInfo.h>

Inheritance diagram for ThePEG::Helicity::FermionSpinInfo:

[legend]

Public Member Functions
Standard constructors and destructors.
	FermionSpinInfo ()
	Default constructor.

	FermionSpinInfo (const Lorentz5Momentum &p, bool time)
	Standard Constructor.

Public Member Functions inherited from ThePEG::SpinInfo
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.

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.

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.

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 ()
	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.

void	update () const
	Method to handle the delelation.

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.

Set and get methods for the basis state.
std::array< LorentzSpinor< SqrtEnergy >, 2 >	_productionstates
	basis states in the frame in which the particle was produced

std::array< LorentzSpinor< SqrtEnergy >, 2 >	_currentstates
	basis states in the current frame of the particle

std::array< LorentzSpinor< SqrtEnergy >, 2 >	_decaystates
	basis states in the frame in which the particle decays

bool	_decaycalc
	True if the decay state has been set.

void	setBasisState (unsigned int hel, const LorentzSpinor< SqrtEnergy > &in) const
	Set the basis state, this is production state.

void	setDecayState (unsigned int hel, const LorentzSpinor< SqrtEnergy > &in) const
	Set the basis state for the decay.

const LorentzSpinor< SqrtEnergy > &	getProductionBasisState (unsigned int hel) const
	Get the basis state for the production for the given helicity, hel (which is 0 or 1 as described above.)

const LorentzSpinor< SqrtEnergy > &	getCurrentBasisState (unsigned int hel) const
	Get the current basis state for the given helicity, hel (which is 0 or 1 as described above.)

const LorentzSpinor< SqrtEnergy > &	getDecayBasisState (unsigned int hel) const
	Get the basis state for the decay for the given helicity, hel (which is 0 or 1 as described above.)

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

virtual void	undecay () const
	Undecay.

virtual void	reset ()
	Reset.

virtual EIPtr	clone () const
	Standard clone method.

static void	Init ()
	Standard Init function.

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

Additional Inherited Members
Public Types inherited from ThePEG::SpinInfo
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.

Static Public Member Functions inherited from ThePEG::SpinInfo
static void	Init ()
	Standard Init function.

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 FermionSpinInfo class inherits from the SpinInfo class and implements the storage of the basis vectors for a spin-1/2 particle.

The basis states are the u-spinors for a particle and the v-spinors for an antiparticle. The barred spinors can be obtained from these.

These basis states should be set by either matrixelements or decayers which are capable of generating spin correlation information.

The basis states in the rest frame of the particles can then be accessed by decayers to produce the correct correlations.

N.B. in our convention 0 is the \(-\frac12\) helicity state and 1 is the \(+\frac12\) helicity state.

Author: Peter Richardson

Definition at line 40 of file FermionSpinInfo.h.

Constructor & Destructor Documentation

◆ FermionSpinInfo() [1/2]

ThePEG::Helicity::FermionSpinInfo::FermionSpinInfo ( )

inline

Default constructor.

Definition at line 49 of file FermionSpinInfo.h.

◆ FermionSpinInfo() [2/2]

ThePEG::Helicity::FermionSpinInfo::FermionSpinInfo	(	const Lorentz5Momentum &	p,
		bool	time
	)

inline

Standard Constructor.

Parameters

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

Definition at line 57 of file FermionSpinInfo.h.

Member Function Documentation

◆ clone()

virtual EIPtr ThePEG::Helicity::FermionSpinInfo::clone ( ) const

virtual

Standard clone method.

Reimplemented from ThePEG::SpinInfo.

◆ getCurrentBasisState()

const LorentzSpinor< SqrtEnergy > & ThePEG::Helicity::FermionSpinInfo::getCurrentBasisState ( unsigned int hel ) const

inline

Get the current basis state for the given helicity, hel (which is 0 or 1 as described above.)

Definition at line 102 of file FermionSpinInfo.h.

References _currentstates.

◆ getDecayBasisState()

const LorentzSpinor< SqrtEnergy > & ThePEG::Helicity::FermionSpinInfo::getDecayBasisState ( unsigned int hel ) const

inline

Get the basis state for the decay for the given helicity, hel (which is 0 or 1 as described above.)

Definition at line 111 of file FermionSpinInfo.h.

References _currentstates, _decaycalc, and _decaystates.

◆ getProductionBasisState()

const LorentzSpinor< SqrtEnergy > & ThePEG::Helicity::FermionSpinInfo::getProductionBasisState ( unsigned int hel ) const

inline

Get the basis state for the production for the given helicity, hel (which is 0 or 1 as described above.)

Definition at line 93 of file FermionSpinInfo.h.

References _productionstates.

◆ reset()

virtual void ThePEG::Helicity::FermionSpinInfo::reset ( )

inlinevirtual

Reset.

Reimplemented from ThePEG::SpinInfo.

Definition at line 137 of file FermionSpinInfo.h.

References _currentstates, _productionstates, ThePEG::SpinInfo::reset(), and undecay().

◆ setBasisState()

void ThePEG::Helicity::FermionSpinInfo::setBasisState	(	unsigned int	hel,
		const LorentzSpinor< SqrtEnergy > &	in
	)		const

inline

Set the basis state, this is production state.

Parameters

hel	the helicity (0 or 1 as described above.)
in	the LorentzSpinor for the given helicity.

Definition at line 70 of file FermionSpinInfo.h.

References _currentstates, and _productionstates.

◆ setDecayState()

void ThePEG::Helicity::FermionSpinInfo::setDecayState	(	unsigned int	hel,
		const LorentzSpinor< SqrtEnergy > &	in
	)		const

inline

Set the basis state for the decay.

Parameters

hel	the helicity (0 or 1 as described above.)
in	the LorentzSpinor for the given helicity.

Definition at line 82 of file FermionSpinInfo.h.

References _decaycalc, and _decaystates.

◆ transform()

virtual void ThePEG::Helicity::FermionSpinInfo::transform	(	const LorentzMomentum &	,
		const LorentzRotation &
	)

virtual

Perform a lorentz rotation of the spin information.

Reimplemented from ThePEG::SpinInfo.

◆ undecay()

virtual void ThePEG::Helicity::FermionSpinInfo::undecay ( ) const

inlinevirtual

Undecay.

Reimplemented from ThePEG::SpinInfo.

Definition at line 129 of file FermionSpinInfo.h.

References _decaycalc, and ThePEG::SpinInfo::undecay().

Referenced by reset().

Member Data Documentation

◆ _currentstates

std::array<LorentzSpinor<SqrtEnergy>,2> ThePEG::Helicity::FermionSpinInfo::_currentstates

mutableprivate

basis states in the current frame of the particle

Definition at line 172 of file FermionSpinInfo.h.

Referenced by getCurrentBasisState(), getDecayBasisState(), reset(), and setBasisState().

◆ _decaycalc

bool ThePEG::Helicity::FermionSpinInfo::_decaycalc

mutableprivate

True if the decay state has been set.

Definition at line 182 of file FermionSpinInfo.h.

Referenced by getDecayBasisState(), setDecayState(), and undecay().

◆ _decaystates

std::array<LorentzSpinor<SqrtEnergy>,2> ThePEG::Helicity::FermionSpinInfo::_decaystates

mutableprivate

basis states in the frame in which the particle decays

Definition at line 177 of file FermionSpinInfo.h.

Referenced by getDecayBasisState(), and setDecayState().

◆ _productionstates

std::array<LorentzSpinor<SqrtEnergy>,2> ThePEG::Helicity::FermionSpinInfo::_productionstates

mutableprivate

basis states in the frame in which the particle was produced

Definition at line 167 of file FermionSpinInfo.h.

Referenced by getProductionBasisState(), reset(), and setBasisState().

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

FermionSpinInfo.h

Public Member Functions

Set and get methods for the basis state.

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ FermionSpinInfo() [1/2]

◆ FermionSpinInfo() [2/2]

Member Function Documentation

◆ clone()

◆ getCurrentBasisState()

◆ getDecayBasisState()

◆ getProductionBasisState()

◆ reset()

◆ setBasisState()

◆ setDecayState()

◆ transform()

◆ undecay()

Member Data Documentation

◆ _currentstates

◆ _decaycalc

◆ _decaystates

◆ _productionstates