Helicity matrix element for a tau decay into three mesons (base class). More...

#include <HelicityMatrixElements.h>

Inheritance diagram for HMETau2ThreeMesons:

Public Member Functions
void	initConstants ()
	Initialize constants for the helicity matrix element. More...

void	initHadronicCurrent (vector< HelicityParticle > &)
	Initialize the hadronic current for the helicity matrix element. More...

Public Member Functions inherited from HMETauDecay
virtual void	initWaves (vector< HelicityParticle > &)
	Initialize wave functions for the helicity matrix element. More...

virtual complex	calculateME (vector< int >)
	Return element for the helicity matrix element.

virtual double	decayWeightMax (vector< HelicityParticle > &)
	Return the maximum decay weight for the helicity matrix element. More...

Public Member Functions inherited from HelicityMatrixElement
	HelicityMatrixElement ()
	Constructor and destructor.

virtual void	initPointers (ParticleData , CoupSM , Settings *=0)
	Initialize the physics matrices and pointers. More...

virtual HelicityMatrixElement *	initChannel (vector< HelicityParticle > &)
	Initialize the channel. More...

virtual double	decayWeight (vector< HelicityParticle > &)
	Calculate the matrix element weight for a decay. More...

virtual void	calculateD (vector< HelicityParticle > &)
	Calculate the decay matrix for a particle. More...

virtual void	calculateRho (unsigned int, vector< HelicityParticle > &)
	Calculate the density matrix for a particle. More...

void	setFermionLine (int, HelicityParticle &, HelicityParticle &)
	Set a fermion line. More...

virtual complex	breitWigner (double s, double M, double G)
	Calculate Breit-Wigner's with running widths and fixed. More...

virtual complex	sBreitWigner (double m0, double m1, double s, double M, double G)
	Return an s-wave BreitWigner.

virtual complex	pBreitWigner (double m0, double m1, double s, double M, double G)
	Return a p-wave BreitWigner.

virtual complex	dBreitWigner (double m0, double m1, double s, double M, double G)
	Return a d-wave BreitWigner.

Protected Types
enum	Mode { Pi0Pi0Pim, PimPimPip, Pi0PimK0b, PimPipKm, Pi0PimEta, PimKmKp, Pi0K0Km, KlPimKs, Pi0Pi0Km, KlKlPim, PimKsKs, PimK0bK0, Uknown }
	Decay mode of the tau.

Protected Member Functions
virtual void	initMode ()
	Initialize decay mode and resonance constants (called by initConstants). More...

virtual void	initResonances ()

virtual void	initMomenta (vector< HelicityParticle > &)
	Initialize the momenta. More...

virtual complex	F1 ()
	Form factors.

virtual complex	F2 ()

virtual complex	F3 ()

virtual complex	F4 ()

virtual double	a1PhaseSpace (double)
	Phase space and Breit-Wigner for the a1. More...

virtual complex	a1BreitWigner (double)

complex	T (double m0, double m1, double s, vector< double > &M, vector< double > &G, vector< double > &W)
	Sum running p and fixed width Breit-Wigner resonances. More...

complex	T (double s, vector< double > &M, vector< double > &G, vector< double > &W)
	Return summed weighted fixed width Breit-Wigner resonances.

Protected Member Functions inherited from HMETauDecay
virtual void	calculateResonanceWeights (vector< double > &, vector< double > &, vector< complex > &)
	Calculate complex resonance weights given a phase and amplitude vector.

Protected Attributes
Mode	mode {}

double	s1 {}
	Center of mass energies and momenta.

double	s2 {}

double	s3 {}

double	s4 {}

Wave4	q {}

Wave4	q2 {}

Wave4	q3 {}

Wave4	q4 {}

complex	a1BW {}
	Stored a1 Breit-Wigner (for speed).

Protected Attributes inherited from HelicityMatrixElement
double	DECAYWEIGHTMAX
	Maximum decay weight. WARNING: hardcoded constant.

vector< GammaMatrix >	gamma
	Physics matrices.

vector< int >	pMap
	Particle map vector.

vector< int >	pID
	Particle ID vector.

vector< double >	pM
	Particle mass vector.

vector< vector< Wave4 > >	u
	Wave functions.

ParticleData *	particleDataPtr
	Pointer to particle data.

CoupSM *	coupSMPtr
	Pointer to Standard Model constants.

Settings *	settingsPtr
	Pointer to Settings.

Detailed Description

Helicity matrix element for a tau decay into three mesons (base class).

Member Function Documentation

complex a1BreitWigner ( double s )

protectedvirtual

Return the Breit-Wigner for the a1. Implements equation 3.18 of Z. Phys. C48 (1990) 445-452.

Mass of the a1.

Width of the a1.

double a1PhaseSpace ( double s )

protectedvirtual

Phase space and Breit-Wigner for the a1.

Return the phase space factor for the a1. Implements equation 3.16 of Z. Phys. C48 (1990) 445-452.

Mass of the charged pion.

Mass of the rho.

void initConstants ( )

virtual

Initialize constants for the helicity matrix element.

Tau decay matrix element for tau decay into three mesons. This matrix element provides a base class for all implemented three meson decays. mode: three meson decay mode of the tau initMode(): initialize the decay mode initResonances(): initialize the resonance constants s1, s2, s3, s4: center-of-mass energies q, q2, q3, q4: summed and individual hadronic momentum four-vectors a1BW: stored value of a1BreitWigner for speed a1PhaseSpace(s): phase space factor for the a1 a1BreitWigner(s): Breit-Wigner for the a1 T(m0, m1, s, M, G, W): sum weighted p-wave Breit-Wigners T(s, M, G, W): sum weighted fixed width Breit-Wigners F1(), F2(), F3(), F4(): sub-current form factors

Reimplemented from HelicityMatrixElement.

void initHadronicCurrent ( vector< HelicityParticle > & p )

virtual

Initialize the hadronic current for the helicity matrix element.

Initialize the momenta.

Calculate the center of mass energies.

Calculate the form factors.

Calculate the hadronic current.

Reimplemented from HMETauDecay.

void initMode ( )

protectedvirtual

Initialize decay mode and resonance constants (called by initConstants).

Initialize the tau decay mode.

void initMomenta ( vector< HelicityParticle > & p )

protectedvirtual

Initialize the momenta.

Initialize the momenta for the helicity matrix element.

pi-, pi-, pi+ decay and pi0, pi0, pi- decay.

K-, pi-, K+ decay.

K0, pi-, Kbar0 decay.

K_S0, pi-, K_S0 decay.

K_L0, pi-, K_L0 decay.

K_S0, pi-, K_L0 decay.

K-, pi0, K0 decay.

pi0, pi0, K- decay.

K-, pi-, pi+ decay.

pi-, Kbar0, pi0 decay.

pi-, pi0, eta decay.

complex T	(	double	m0,
		double	m1,
		double	s,
		vector< double > &	M,
		vector< double > &	G,
		vector< double > &	W
	)

protected

Sum running p and fixed width Breit-Wigner resonances.

Return summed weighted running p Breit-Wigner resonances.

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

include/Pythia8/HelicityMatrixElements.h
src/HelicityMatrixElements.cc

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation