Initial-initial electroweak antenna. More...

#include <VinciaEW.h>

Inheritance diagram for EWAntennaII:

Public Member Functions
	EWAntennaII (BeamParticle beamAPtrIn, BeamParticle beamBPtrIn)
	Constructor.

bool	init (Event &event, int iMotIn, int iRecIn, int iSysIn, vector< EWBranching > &branchings, Settings *settingsPtr) override
	Overridden virtual functions. More...

bool	isInitial () override

double	generateTrial (double q2Start, double q2End, double alphaIn) override
	Generate a trial. More...

bool	acceptTrial (Event &event) override
	Accept a trial. More...

void	updateEvent (Event &event) override
	Update an event. More...

void	updatePartonSystems (Event &event) override
	Update a parton system. More...

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

void	print ()
	Print, must be implemented by base classes.

void	initPtr (Info infoPtrIn, VinciaCommon vinComPtrIn, AlphaEM alphaPtrIn, AmpCalculator ampCalcPtrIn)
	Initialize pointers.

void	setVerbose (int verboseIn)
	Set verbosity level.

int	getIndexMot ()
	Return index.

int	getIndexRec ()

bool	isSplitToFermions ()
	Check if splitting to fermions, inital, or resoance.

virtual bool	isResonanceDecay ()

bool	selectChannel (int idx, const double &cSum, const map< double, int > &cSumSoFar, int &idi, int &idj, double &mi2, double &mj2)
	Select a channel.

Additional Inherited Members
Protected Attributes inherited from EWAntenna
int	iMot
	Indices, PID, and polarization of I, K in Pythia event record.

int	iRec

int	idMot

int	idRec

int	polMot

Vec4	pMot
	Momenta of antenna constituents.

Vec4	pRec

double	sAnt
	Masses and invariants of antenna constituents.

double	mMot

double	mMot2

double	mRec

double	mRec2

double	alpha
	Overestimate of QED coupling.

int	iSys
	Parton system this antenna is part of.

vector< EWBranching >	brVec
	EW branchings.

bool	hasTrial
	Trial variables.

double	q2Trial

double	sijTrial

double	sjkTrial

int	poliTrial

int	poljTrial

vector< Vec4 >	pNew
	Outgoing momenta after branching.

double	c0Sum
	Info on coefficents.

double	c1Sum

double	c2Sum

double	c3Sum

map< double, int >	c0SumSoFar

map< double, int >	c1SumSoFar

map< double, int >	c2SumSoFar

map< double, int >	c3SumSoFar

double	q2Match
	Matching scale.

int	jNew
	Information for partonSystems.

unordered_map< int, int >	iReplace

double	shat

EWBranching *	brTrial {}
	Pointers.

Info *	infoPtr {}

Rndm *	rndmPtr {}

Logger *	loggerPtr {}

PartonSystems *	partonSystemsPtr {}

VinciaCommon *	vinComPtr {}

AlphaEM *	alphaPtr {}

AmpCalculator *	ampCalcPtr {}

bool	doBosonInterference
	Settings.

int	verbose
	Verbosity.

Detailed Description

Initial-initial electroweak antenna.

Member Function Documentation

bool acceptTrial ( Event & event )

overridevirtual

Accept a trial.

Mark trial as used.

Indices, on-shell mass, phase space invariants.

Check if I is A or B

Check on-shell phase space.

Compute post-branching energies of initial state.

Get new initial-state momentum fractions.

Check if new energies don't exceed hadronic maxima. First add up all initial state energies.

Then adjust for this branching.

Set headroom of 2% in accordance with the rest of Vincia.

Next, compute accept probability.

Compute PDF ratios and add it to the accept probability.

Compute the trial kernel and collinear momentum fractions.

Physical kernel.

Add antenna ratio.

Check if the veto probability is valid.

Perform veto.

Branching accepted! Now select a spin state.

Sample Breit-Wigner mass for the kinematics, check off-shell phase space.

Check if we veto resonances with offshellness > q2.

Pre- and post-branching momenta, global recoil momenta.

Collect the recoiling final state particles.

Generate phi.

Kinematics and return.

Implements EWAntenna.

double generateTrial	(	double	q2Start,
		double	q2End,
		double	alphaIn
	)

overridevirtual

Generate a trial.

Cutoff value is the same as for FF, but it is not kinematically identical.

Zeta boundaries.

Prevent NaN phase space boundaries.

Find largest mj2 in branchings. Required due to the asymmetric phase space bounds.

Expand square root to prevent numerical issues.

Check if there is any phase space available.

Zeta integral and trial generation weight; generate a new scale.

Generate z.

Select channel and get invariants.

Note that the accept prob might be negative. In those cases, the point is outside phase space and would be vetoed anyway.

Return.

Implements EWAntenna.

bool init	(	Event &	event,
		int	iMotIn,
		int	iRecIn,
		int	iSysIn,
		vector< EWBranching > &	branchings,
		Settings *	settingsPtr
	)

overridevirtual

Overridden virtual functions.

Initial-initial electroweak antenna.

Initialize.

Settings.

Initialize variables.

Masses are set to zero explicitly.

Hadronic invariant mass

Hadronic momentum fractions

Sanity check for phase space being open.

Set system.

Store branchings.

Find coefficients for overestimates.

Only use c0 for initial state radiation.

Implements EWAntenna.

void updateEvent ( Event & event )

overridevirtual

Update an event.

Setup system, indices, masses, colors. Carry I color indices to i.

Save information for parton system.

Set old particles to negative.

Update beam daughters.

Update event for global recoil.

Copy the recoiler.

Change the momentum.

Save information for parton system.

Fix sHat for parton system.

Implements EWAntenna.

void updatePartonSystems ( Event & event )

overridevirtual

Update a parton system.

Get new initial state indices from the updated parton system.

Update beams.

Reimplemented from EWAntenna.

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

include/Pythia8/VinciaEW.h
src/VinciaEW.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation