ThePEG::Helicity::FermionSpinInfo Class Reference

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:

List of all members.

Public Member Functions
virtual void	transform (const LorentzMomentum &, const LorentzRotation &)
	Perform a lorentz rotation of the spin information.
virtual EIPtr	clone () const
	Standard clone method.
Standard constructors and destructors.
	FermionSpinInfo ()
	Default constructor.
	FermionSpinInfo (const Lorentz5Momentum &p, bool time)
	Standard Constructor.
Set and get methods for the basis state.
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.
Static Public Member Functions
static void	Init ()
	Standard Init function.
Private Member Functions
FermionSpinInfo &	operator= (const FermionSpinInfo &)
	Private and non-existent assignment operator.
Private Attributes
vector< LorentzSpinor < SqrtEnergy > >	_productionstates
	basis states in the frame in which the particle was produced
vector< LorentzSpinor < SqrtEnergy > >	_currentstates
	basis states in the current frame of the particle
vector< LorentzSpinor < SqrtEnergy > >	_decaystates
	basis states in the frame in which the particle decays
bool	_decaycalc
	True if the decay state has been set.
Static Private Attributes
static NoPIOClassDescription < FermionSpinInfo >	initFermionSpinInfo
	Describe a concrete class without persistent data.

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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 helicity state and 1 is the helicity state.

Author:

Peter Richardson

Definition at line 40 of file FermionSpinInfo.h.

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Constructor & Destructor Documentation

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 58 of file FermionSpinInfo.h.

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Member Function Documentation

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 73 of file FermionSpinInfo.h.

References _currentstates, and _productionstates.

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 85 of file FermionSpinInfo.h.

References _decaycalc, and _decaystates.

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 96 of file FermionSpinInfo.h.

References _productionstates.

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 105 of file FermionSpinInfo.h.

References _currentstates.

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 114 of file FermionSpinInfo.h.

References _currentstates, _decaycalc, and _decaystates.

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

• FermionSpinInfo.h