ExternalMEsMadgraph Class Reference

External matrix element class specifically for MadGraph. More...

#include <ExternalMEsMadgraph.h>

Inheritance diagram for ExternalMEsMadgraph:

Public Member Functions
	ExternalMEsMadgraph (Pythia *, Settings *, Logger *)
	Constructor.
	~ExternalMEsMadgraph ()
	Destructor.
bool	init () override
	Initialisers. More...
bool	initVincia (Info *infoPtrIn) override
bool	initDire (Info *, string card) override
	Initialise the Madgraph model, parameters, and couplings for use in Dire. More...
bool	isAvailable (vector< int > idIn, vector< int > idOut) override
	Methods to check availability of matrix elements. More...
bool	isAvailable (const Pythia8::Event &event) override
bool	isAvailable (const Pythia8::Event &event, int iBeg=3) override
bool	isAvailable (const vector< Particle > &state) override
double	calcME2 (const vector< Particle > &state) override
	Get the matrix element squared for a particle state. More...
double	calcME2 (const Event &event, const int iBeg=3) override
Public Member Functions inherited from ExternalMEs
	ExternalMEs ()=default
	Destructor.
virtual void	initPtrs (Info *infoPtrIn)
	Initialisers for pointers. More...
virtual void	setColourMode (int colModeIn)
	Setters.
virtual void	setHelicityMode (int helModeIn)
virtual void	setIncludeSymmetryFac (bool doInclIn)
virtual void	setIncludeHelicityAvgFac (bool doInclIn)
virtual void	setIncludeColourAvgFac (bool doInclIn)
virtual int	colourMode ()
	Getters.
virtual int	helicityMode ()
virtual bool	includeSymmetryFac ()
virtual bool	includeHelicityAvgFac ()
virtual bool	includeColourAvgFac ()
virtual map< vector< int >, double >	getHelicityAmplitudes ()

Additional Inherited Members
Protected Member Functions inherited from ExternalMEs
void	fillIds (const Event &event, vector< int > &in, vector< int > &out, int iBeg=3) const
	Fill a vector of IDs, from an event, starting from entry i = iBeg. More...
void	fillMoms (const Event &event, vector< Vec4 > &p, int iBeg=3) const
	Fill a vector of momenta, from an event, starting from entry i = iBeg. More...
void	fillCols (const Event &event, vector< int > &colors, int iBeg=3) const
	Fill a vector of colors, from an event, starting from entry i = iBeg. More...
vector< vector< double > >	fillMoms (const Event &event, int iBeg=3) const
	Return the momenta, from an event, starting from entry i = iBeg. More...
Protected Attributes inherited from ExternalMEs
int	colMode {1}
	Colour mode (0: strict LC, 1: LC, 2: LC sum, 3: FC).
map< vector< int >, double >	me2hel
	Saved list of helicity components for last ME evaluated.
int	helMode {1}
	Helicity mode (0: explicit helicity sum, 1: implicit helicity sum).
bool	inclSymFac {false}
	Symmetry and averaging factors.
bool	inclHelAvgFac {false}
bool	inclColAvgFac {false}
Info *	infoPtr {}
	Pointers to VINCIA and Pythia 8 objects.
Logger *	loggerPtr {}
CoupSM *	coupSMPtr {}
ParticleData *	particleDataPtr {}
Rndm *	rndmPtr {}
Settings *	settingsPtr {}
SusyLesHouches *	slhaPtr {}
bool	isInitPtr {false}
	Is initialized.
bool	isInit {false}

Detailed Description

External matrix element class specifically for MadGraph.

Member Function Documentation

double calcME2 ( const vector< Particle > &  state )

overridevirtual

Get the matrix element squared for a particle state.

Calcuate the squared matrix element.

Prepare lists.

Reimplemented from ExternalMEs.

double calcME2 ( const Event &  event, const int  iBeg = 3  )

overridevirtual

Prepare lists.

Reimplemented from ExternalMEs.

bool init ( )

overridevirtual

Initialisers.

Initialise the Madgraph model, parameters, and couplings for use in Vincia.

Reimplemented from ExternalMEs.

bool initDire ( Info *  , string  card  )

overridevirtual

Initialise the Madgraph model, parameters, and couplings for use in Dire.

Redirect output so that Dire can print MG5 initialization.

Do not include averaging or symmetry factors in MG5.

Set whether symmetry and averaging factors are applied in calcME2().

Leading-colour colour-ordered amplitude only (can be reset later).

Implicitly sum over helicities (can be reset later).

Restore print-out.

Reimplemented from ExternalMEs.

bool initVincia ( Info *  infoPtrIn )

overridevirtual

Check if pointers initialized.

Create new model instance.

In the VINCIA context, alphaS_MGME = 1/4pi (- > gS = 1; we control the running separately). Thus, even the Madgraph "dependent" parameters only need to be set once.

Alternatively, we could evaluate the QCD coupling at MZ but should then use a coupling definition from a Vincia parameter list rather than PYTHIA's couplings. double muDefME = 91.2; double alpS = coupSMPtr->alphaS(pow2(muDefME));

The following is equivalent to PY8MEs::updateModelDependentCouplingsWithPY8(...)

Construct Madgraph process library.

Do not include averaging or symmetry factors in MG5.

Set whether symmetry and averaging factors are applied in calcME2().

Leading-colour colour-ordered amplitude only (can be reset later).

Implicitly sum over helicities (can be reset later).

Reimplemented from ExternalMEs.

bool isAvailable ( vector< int >  idIn, vector< int >  idOut  )

overridevirtual

Methods to check availability of matrix elements.

Check if a matrix element is available.

Reimplemented from ExternalMEs.

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

• include/Pythia8Plugins/ExternalMEsMadgraph.h