Base class for trial generators. More...

#include <VinciaTrialGenerators.h>

Inheritance diagram for TrialGenerator:

Public Member Functions
	TrialGenerator (bool isSectorIn, TrialGenType trialGenTypeIn, BranchType branchTypeIn, ZetaGeneratorSet *zetaGenSet)
	Main constructor.

virtual	~TrialGenerator ()=default
	Destructor.

void	setupZetaGens (ZetaGeneratorSet *zetaGenSet)
	Set pointers to zetaGenerators. More...

virtual void	reset (double Q2min, double s, const vector< double > &masses, enum AntFunType antFunType, double xA=1., double xB=1.)
	Re-calculate the current zeta limits and integrals. More...

virtual double	genQ2 (double Q2MaxNow, Rndm rndmPtr, const EvolutionWindow evWindowPtrIn, double colFac, double wtIn, Logger *loggerPtr, int verboseIn)
	Generate the next trial scale. More...

virtual bool	genInvariants (double sAnt, const vector< double > &masses, vector< double > &invariants, Rndm rndmPtr, Logger loggerPtr, int verboseIn)
	Get the invariants. More...

virtual double	aTrial (vector< double > &invariants, const vector< double > &masses, int verboseIn)
	Calculate the trial based on invariants and saved quantities. More...

virtual double	aTrialStrip (vector< double > &invariants, const vector< double > &masses, int verboseIn)
	Calculate the colour and coupling stripped antenna function. More...

virtual void	resetTrial ()
	Delete the current trial. More...

virtual void	needsNewTrial ()
	Mark trial as used.

int	getSector ()
	Return the sector.

Protected Member Functions
virtual void	calcKallenFac (double, const vector< double > &)
	Calculate the Kallen factor.

virtual void	calcRpdf (const vector< double > &)
	Calculate the PDF ratio.

void	addGenerator (ZetaGeneratorSet *zetaGenSet, Sector sector=Sector::Default)
	TrialGenerator base class functions. More...

Protected Attributes
bool	isInit {false}
	True when init succeeds.

const bool	isSector
	Information set at construction.

const TrialGenType	trialGenTypeSav

const BranchType	branchType

double	kallenFacSav {1.}
	Common prefactors to the trial integral.

double	Rpdf {1.}

double	sAntSav {}
	Information about the antenna.

vector< double >	massesSav

bool	hasTrial {false}
	Information about the trial.

double	q2Sav {}

double	colFacSav {}

const EvolutionWindow *	evWindowSav {}

Sector	sectorSav

map< Sector, ZetaGeneratorPtr >	zetaGenPtrs

map< Sector, pair< double, double > >	zetaLimits
	Map from sector to the corresponding zeta phase-space limits.

map< Sector, double >	IzSav
	Save the zeta integrals.

map< Sector, bool >	isActiveSector
	Save which sectors are currently active.

Detailed Description

Base class for trial generators.

Member Function Documentation

void addGenerator	(	ZetaGeneratorSet *	zetaGenSet,
		Sector	sector = `Sector::Default`
	)

protected

TrialGenerator base class functions.

Add a zeta generator for a given sector.

double aTrial	(	vector< double > &	invariants,
		const vector< double > &	masses,
		int	verboseIn
	)

virtual

Calculate the trial based on invariants and saved quantities.

Fetch colour and coupling stripped antenna function.

Multiply by colour factor.

Multiply by alphaS.

Print.

double aTrialStrip	(	vector< double > &	invariants,
		const vector< double > &	masses,
		int	verboseIn
	)

virtual

Calculate the colour and coupling stripped antenna function.

Loop over sectors.

Skip inactive sectors.

Add contribution from this sector.

bool genInvariants	(	double	sAnt,
		const vector< double > &	masses,
		vector< double > &	invariants,
		Rndm *	rndmPtr,
		Logger *	loggerPtr,
		int	verboseIn
	)

virtual

Get the invariants.

Retrieve limits of zeta integral.

Generate a value of zeta.

Check that it is inside the physical limits. TODO fix xA and xB;

Check if we generated a physical zeta, now that we know Q2.

Calculate invariants from q2 and zeta.

double genQ2	(	double	Q2MaxNow,
		Rndm *	rndmPtr,
		const EvolutionWindow *	evWindowPtrIn,
		double	colFac,
		double	wtIn,
		Logger *	loggerPtr,
		int	verboseIn
	)

virtual

Generate the next trial scale.

Reset.

Save common variables.

Get multiplicative prefactors to trial integral.

Possible enhancement weights.

Fetch minimum q2 for this window.

Loop over sectors (generators).

Skip inactive sectors.

Re-calculate hull of current phase space limits for this window.

Save hull of limits.

Evaluate zeta integral. Note: do not multiply by anything, since used for veto below.

Get additional factors for zeta integral.

Check if phase space is closed.

Convert to global trial.

Now generate q2.

Optimise by checking narrower (physical) zeta hull after trial.

Get log of random number.

Fixed alphaS.

Use max possible value for alphaS.

Inverse of Q2 integral for fixed alphaS.

Calculate factors for running alphas.

Inverse of Q2 integral for running alphas.

If we dropped below window edge, just accept and continue.

Else check if we are inside the narrower zeta range defined by this q2.

Accept this range with probability IzPhys/Iz:

Update saved limits.

Safety check.

Winner so far.

Save which sector.

void reset	(	double	Q2min,
		double	s,
		const vector< double > &	masses,
		enum AntFunType	antFunType,
		double	xA = `1.`,
		double	xB = `1.`
	)

virtual

Re-calculate the current zeta limits and integrals.

Re-calculate the current zeta limits using absolute minimum q2. N.B. Base class doesn't use x fractions.

Throw away any stored trials.

Calculate common factors.

Loop over sectors (generators).

Check if this sector is active and save.

Calculate hull of current phase space limits.

Save hull of zeta limits.

void resetTrial ( )

virtual

Delete the current trial.

Clear all saved trial variables.

void setupZetaGens ( ZetaGeneratorSet * zetaGenSet )

Set pointers to zetaGenerators.

Initialise the zeta generators.

Check for incompatible type.

Sector shower: add one generator per sector (if it exists).

For global FF and RF only one generator needed.

For global IF need two generators (initial-state leg sectorised).

For global II need three generators (initial-state legs sectorised).

Member Data Documentation

map<Sector, ZetaGeneratorPtr> zetaGenPtrs

protected

Map from sector to the correct zeta generator. (note these live inside a ZetaGeneratorSet)

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

include/Pythia8/VinciaTrialGenerators.h
src/VinciaTrialGenerators.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation