ThePEG::Helicity::VVTVertex Class Reference

The VVTVertex class is the implementation of the vector-vector-tensor vertex. More...

#include <VVTVertex.h>

Inheritance diagram for ThePEG::Helicity::VVTVertex:

List of all members.

Public Member Functions

virtual void setCoupling (Energy2 q2, tcPDPtr part1, tcPDPtr part2, tcPDPtr part3)=0

Calculate the couplings.

Complex evaluate (Energy2 q2, const VectorWaveFunction &vec1, const VectorWaveFunction &vec2, const TensorWaveFunction &ten3)

Members to calculate the helicity amplitude expressions for vertices and off-shell particles.

TensorWaveFunction evaluate (Energy2 q2, int iopt, tcPDPtr out, const VectorWaveFunction &vec1, const VectorWaveFunction &vec2, Energy mass=-GeV, Energy width=-GeV)

Evaluate the off-shell tensor coming from the vertex.

VectorWaveFunction evaluate (Energy2 q2, int iopt, tcPDPtr out, const VectorWaveFunction &vec1, const TensorWaveFunction &ten3, Energy mass=-GeV, Energy width=-GeV)

Evaluate the off-shell vector coming from the vertex.

Static Public Member Functions

static void Init ()

Standard Init function used to initialize the interfaces.

Private Member Functions

VVTVertex & operator= (const VVTVertex &)

Private and non-existent assignment operator.

Static Private Attributes

static
AbstractNoPIOClassDescription
< VVTVertex > initVVTVertex

Describe a concrete class with persistent data.

Detailed Description

The VVTVertex class is the implementation of the vector-vector-tensor vertex.

It inherits from the AbstractVVTVertex class for the storage of the particles interacting at the vertex and implements the helicity amplitude calculations.

All implementations of this vertex should inherit from it and implement the virtual setCoupling member.

The vertex has the form

$\left[m^2_v+k_1\cdot k_2)C_{\mu\nu,\rho\sigma}+D_{\mu\nu,\rho\sigma}\right] \epsilon_1^\rho\epsilon_2^\sigma \epsilon_3^{\mu\nu}$

where

$C_{\mu\nu,\rho\sigma}=g_{\mu\rho}g_{\nu\sigma}+g_{\mu\sigma}g_{\nu\rho} -g_{\mu\nu}g_{\rho\sigma}$
$D_{\mu\nu,\rho\sigma}= g_{\mu\nu}k_{1\sigma}k_{2\rho}-\left[g_{\mu\sigma}k_{1\nu}k_{2\rho}+g_{\mu\rho}k_{1\sigma}k_{2\nu}-g_{\rho\sigma}k_{1\mu}k_{2\nu}+(\mu\leftrightarrow\nu)\right]$

See also:: AbstractVVTVertex

Definition at line 46 of file VVTVertex.h.

Member Function Documentation

Complex ThePEG::Helicity::VVTVertex::evaluate	(	Energy2	q2,
		const VectorWaveFunction &	vec1,
		const VectorWaveFunction &	vec2,
		const TensorWaveFunction &	ten3
	)			`[virtual]`

Members to calculate the helicity amplitude expressions for vertices and off-shell particles.

Evalulate the vertex.

Parameters:

	q2	The scale for the coupling at the vertex.
	vec1	The wavefunction for the first vector.
	vec2	The wavefunction for the second vector.
	ten3	The wavefunction for the tensor.

Implements ThePEG::Helicity::AbstractVVTVertex.

TensorWaveFunction ThePEG::Helicity::VVTVertex::evaluate	(	Energy2	q2,
		int	iopt,
		tcPDPtr	out,
		const VectorWaveFunction &	vec1,
		const VectorWaveFunction &	vec2,
		Energy	mass = `-GeV`,
		Energy	width = `-GeV`
	)			`[virtual]`

Evaluate the off-shell tensor coming from the vertex.

Parameters:

	q2	The scale for the coupling at the vertex.
	iopt	Option of the shape of the Breit-Wigner for the off-shell tensor.
	out	The ParticleData pointer for the off-shell tensor.
	vec1	The wavefunction for the first vector.
	vec2	The wavefunction for the second vector.
	mass	The mass of the off-shell particle if not taken from the ParticleData object
	width	The width of the off-shell particle if not taken from the ParticleData object

Implements ThePEG::Helicity::AbstractVVTVertex.

VectorWaveFunction ThePEG::Helicity::VVTVertex::evaluate	(	Energy2	q2,
		int	iopt,
		tcPDPtr	out,
		const VectorWaveFunction &	vec1,
		const TensorWaveFunction &	ten3,
		Energy	mass = `-GeV`,
		Energy	width = `-GeV`
	)			`[virtual]`

Evaluate the off-shell vector coming from the vertex.

Parameters:

	q2	The scale for the coupling at the vertex.
	iopt	Option of the shape of the Breit-Wigner for the off-shell vector.
	out	The ParticleData pointer for the off-shell vector.
	vec1	The wavefunction for the first vector.
	ten3	The wavefunction for the tensor.
	mass	The mass of the off-shell particle if not taken from the ParticleData object
	width	The width of the off-shell particle if not taken from the ParticleData object

Implements ThePEG::Helicity::AbstractVVTVertex.

virtual void ThePEG::Helicity::VVTVertex::setCoupling	(	Energy2	q2,
		tcPDPtr	part1,
		tcPDPtr	part2,
		tcPDPtr	part3
	)			`[pure virtual]`

Calculate the couplings.

This method is virtual and must be implemented in classes inheriting from this.

Parameters:

	q2	The scale for the coupling at the vertex.
	part1	The ParticleData pointer for the first particle.
	part2	The ParticleData pointer for the second particle.
	part3	The ParticleData pointer for the third particle.

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

VVTVertex.h


Public Member Functions
virtual void	setCoupling (Energy2 q2, tcPDPtr part1, tcPDPtr part2, tcPDPtr part3)=0
	Calculate the couplings.

Complex	evaluate (Energy2 q2, const VectorWaveFunction &vec1, const VectorWaveFunction &vec2, const TensorWaveFunction &ten3)
	Members to calculate the helicity amplitude expressions for vertices and off-shell particles.
TensorWaveFunction	evaluate (Energy2 q2, int iopt, tcPDPtr out, const VectorWaveFunction &vec1, const VectorWaveFunction &vec2, Energy mass=-GeV, Energy width=-GeV)
	Evaluate the off-shell tensor coming from the vertex.
VectorWaveFunction	evaluate (Energy2 q2, int iopt, tcPDPtr out, const VectorWaveFunction &vec1, const TensorWaveFunction &ten3, Energy mass=-GeV, Energy width=-GeV)
	Evaluate the off-shell vector coming from the vertex.
Static Public Member Functions
static void	Init ()
	Standard Init function used to initialize the interfaces.
Private Member Functions
VVTVertex &	operator= (const VVTVertex &)
	Private and non-existent assignment operator.
Static Private Attributes
static AbstractNoPIOClassDescription < VVTVertex >	initVVTVertex
	Describe a concrete class with persistent data.