PYTHIA  8.303
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HMETwoFermions2GammaZ2TwoFermions Class Reference

#include <HelicityMatrixElements.h>

Inheritance diagram for HMETwoFermions2GammaZ2TwoFermions:
HelicityMatrixElement

Public Member Functions

void initConstants ()
 Helicity matrix element for two fermions -> photon/Z/Z' -> two fermions. More...
 
void initWaves (vector< HelicityParticle > &)
 Initialize wave functions for the helicity matrix element. More...
 
complex calculateME (vector< int >)
 Return element for the helicity matrix element.
 
- 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 HelicityMatrixElementinitChannel (vector< HelicityParticle > &)
 Initialize the channel. More...
 
virtual double decayWeight (vector< HelicityParticle > &)
 Calculate the matrix element weight for a decay. More...
 
virtual double decayWeightMax (vector< HelicityParticle > &)
 Calculate the maximum matrix element decay weight.
 
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.
 

Additional Inherited Members

- Protected Attributes inherited from HelicityMatrixElement
double DECAYWEIGHTMAX
 Maximum decay weight. WARNING: hardcoded constant.
 
vector< GammaMatrixgamma
 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.
 
ParticleDataparticleDataPtr
 Pointer to particle data.
 
CoupSMcoupSMPtr
 Pointer to Standard Model constants.
 
SettingssettingsPtr
 Pointer to Settings.
 

Detailed Description

Helicity matrix element for the hard process of two fermions -> photon/Z/Z' -> two fermions.

Member Function Documentation

void initConstants ( )
virtual

Helicity matrix element for two fermions -> photon/Z/Z' -> two fermions.

Note that there is a double contraction in the Z matrix element, which can be very time consuming. If the two incoming fermions are oriented along the z-axis, their helicities must be opposite for a non-zero matrix element term. Consequently, this check is made to help speed up the matrix element. p0Q: charge of the incoming fermion line p2Q: charge of the outgoing fermion line s: center of mass energy sin2W: sine of the Weinberg angle cos2W: cosine of the Weinberg angle zM: on-shell mass of the Z zG: on-shell width of the Z p0CA: axial coupling of particle 0 to the Z p2CA: axial coupling of particle 2 to the Z p0CV: vector coupling of particle 0 to the Z p2CV: vector coupling of particle 2 to the Z zaxis: true if the incoming fermions are oriented along the z-axis Initialize the constants for the helicity matrix element.

Set the Weinberg angle.

Set the on-shell Z/Z' mass and width.

Set the Z vector and axial couplings to the fermions.

Turn off the gamma/Z/Z' channels.

Set the Z' vector and axial couplings to the fermions.

Set the gamma/Z/Z' channels to include.

Default behavior without settings pointer.

Reimplemented from HelicityMatrixElement.

void initWaves ( vector< HelicityParticle > &  p)
virtual

Initialize wave functions for the helicity matrix element.

Fermion line charge.

Center of mass energy.

Check if incoming fermions are oriented along z-axis.

Reimplemented from HelicityMatrixElement.


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