DireMergingHooks is base class for user input to the merging procedure. More...

#include <DireMergingHooks.h>

Inheritance diagram for DireMergingHooks:

Public Member Functions
virtual int	getNumberOfClusteringSteps (const Event &event, bool resetNjetMax=false)
	Function to return the number of clustering steps for the current event. More...

bool	checkAgainstCut (const Particle &particle)
	Functions used as default merging scales. More...

double	tmsNow (const Event &event)

double	scalems (const Event &event)

void	doIgnoreEmissions (bool doIgnoreIn)
	Functions to steer shower evolution (public to allow for PS plugin). More...

bool	canVetoEmission ()
	Function to allow not counting a trial emission.

bool	doVetoEmission (const Event &)
	Function to check if emission should be rejected. More...

void	init ()
	The DireMergingHooks class. More...

virtual bool	doVetoStep (const Event &process, const Event &event, bool doResonance=false)
	Function to check event veto. More...

virtual bool	setShowerStartingScales (bool isTrial, bool doMergeFirstEmm, double &pTscaleIn, const Event &event, double &pTmaxFSRIn, bool &limitPTmaxFSRin, double &pTmaxISRIn, bool &limitPTmaxISRin, double &pTmaxMPIIn, bool &limitPTmaxMPIin)
	Set starting scales. More...

bool	doMOPS ()

bool	doMEM ()

vector< double >	stoppingScales ()

Public Member Functions inherited from MergingHooks
	MergingHooks ()
	Constructor.

virtual	~MergingHooks ()
	Destructor. More...

virtual double	tmsDefinition (const Event &event)
	Function encoding the functional definition of the merging scale.

virtual double	dampenIfFailCuts (const Event &inEvent)

virtual bool	canCutOnRecState ()

virtual bool	doCutOnRecState (const Event &event)

virtual bool	canVetoTrialEmission ()
	Function to allow not counting a trial emission.

virtual bool	doVetoTrialEmission (const Event &, const Event &)
	Function to check if trial emission should be rejected.

virtual double	hardProcessME (const Event &inEvent)
	Function to calculate the hard process matrix element. More...

double	tms ()
	Function returning the value of the merging scale. More...

double	tmsCut ()

void	tms (double tmsIn)

double	dRijMS ()

double	pTiMS ()

double	QijMS ()

int	nMaxJets ()
	Function returning the value of the maximal number of merged jets.

int	nMaxJetsNLO ()

string	getProcessString ()
	Function to return hard process string.

int	nHardOutPartons ()
	Function to return the number of outgoing partons in the core process.

int	nHardOutLeptons ()
	Function to return the number of outgoing leptons in the core process.

int	nHardOutBosons ()

int	nHardInPartons ()

int	nHardInLeptons ()
	Function to return the number of incoming leptons in the core process.

int	nResInCurrent ()

bool	doUserMerging ()
	Function to determine if user defined merging should be applied.

bool	doMGMerging ()
	Function to determine if automated MG/ME merging should be applied.

bool	doKTMerging ()
	Function to determine if KT merging should be applied.

bool	doPTLundMerging ()
	Function to determine if PTLund merging should be applied.

bool	doCutBasedMerging ()
	Function to determine if cut based merging should be applied.

bool	doCKKWLMerging ()

bool	doUMEPSTree ()

bool	doUMEPSSubt ()

bool	doUMEPSMerging ()

bool	doNL3Tree ()

bool	doNL3Loop ()

bool	doNL3Subt ()

bool	doNL3Merging ()

bool	doUNLOPSTree ()

bool	doUNLOPSLoop ()

bool	doUNLOPSSubt ()

bool	doUNLOPSSubtNLO ()

bool	doUNLOPSMerging ()

bool	doRuntimeAMCATNLOInterface ()
	Function to determine if we have a runtime interface to aMC.

int	nRecluster ()
	Return the number clustering steps that have actually been done.

int	nRequested ()
	Return number of requested additional jets on top of the Born process.

bool	isFirstEmission (const Event &event)
	Output functions to analyse/prepare event for merging. More...

bool	hasEffectiveG2EW ()
	Function to allow effective gg -> EW boson couplings.

bool	allowEffectiveVertex (vector< int > in, vector< int > out)
	Function to allow effective gg -> EW boson couplings.

Event	bareEvent (const Event &inputEventIn, bool storeInputEvent)
	Return event stripped from decay products. More...

bool	reattachResonanceDecays (Event &process)
	Write event with decay products attached to argument. More...

bool	isInHard (int iPos, const Event &event)
	Check if particle at position iPos is part of the hard sub-system. More...

void	orderHistories (bool doOrderHistoriesIn)
	Functions to steer construction of histories. More...

void	allowCutOnRecState (bool doCutOnRecStateIn)

void	doWeakClustering (bool doWeakClusteringIn)
	Function to allow final state clusterings of weak bosons.

bool	checkAgainstCut (const Particle &particle)
	Functions used as default merging scales. More...

double	rhoms (const Event &event, bool withColour)
	Find the minimal Lund pT between coloured partons in the event. More...

double	kTms (const Event &event)
	Function to calculate the minimal kT in the event. More...

double	cutbasedms (const Event &event)

void	doIgnoreEmissions (bool doIgnoreIn)
	Functions to steer shower evolution (public to allow for PS plugin) More...

virtual bool	usesVincia ()

virtual bool	useShowerPlugin ()

bool	includeWGTinXSEC ()

int	nHardNow ()
	Functions to retrieve event veto information.

double	tmsHardNow ()

int	nJetsNow ()

double	tmsNow ()

void	setHardProcessPtr (HardProcess *hardProcIn)

int	nMuRVar ()
	Functions related to renormalization scale variations.

void	printIndividualWeights ()
	Function to print individual merging weight components, for debugging.

void	setShowerPointer (PartonLevel *psIn)

void	storeHardProcessCandidates (const Event &event)
	Generic setup functions. More...

void	setLHEInputFile (string lheFile)

AlphaStrong *	AlphaS_FSR ()
	Functions for output of class members. More...

AlphaStrong *	AlphaS_ISR ()

AlphaEM *	AlphaEM_FSR ()

AlphaEM *	AlphaEM_ISR ()

bool	includeMassive ()

bool	enforceStrongOrdering ()
	Prefer strongly ordered histories.

bool	orderInRapidity ()
	Prefer histories ordered in rapidity and evolution pT.

bool	pickByFull ()
	Pick history probabilistically by full (correct) splitting probabilities.

bool	pickByPoPT2 ()
	Pick history probabilistically, with easier form of probabilities.

bool	includeRedundant ()
	Include redundant terms (e.g. PDF ratios) in the splitting probabilities.

bool	pickBySumPT ()
	Pick by winner-takes-it-all, with minimum sum of scalar evolution pT.

int	unorderedScalePrescip ()

int	unorderedASscalePrescip ()

int	unorderedPDFscalePrescip ()

int	incompleteScalePrescip ()

bool	allowColourShuffling ()
	Allow swapping one colour index while reclustering.

bool	resetHardQRen ()
	Allow use of dynamical renormalisation scale of the core 2-> 2 process.

bool	resetHardQFac ()
	Allow use of dynamical factorisation scale of the core 2-> 2 process.

double	scaleSeparationFactor ()

double	nonJoinedNorm ()

double	fsrInRecNorm ()

double	herwigAcollFSR ()

double	herwigAcollISR ()

double	pT0ISR ()
	ISR regularisation scale.

double	pTcut ()
	Shower cut-off scale.

void	muMI (double mu)
	MI starting scale.

double	muMI ()

double	kFactor (int njet=0)
	Full k-Factor for current event.

double	k1Factor (int njet=0)
	O()-term of the k-Factor for current event.

bool	orderHistories ()

bool	allowCutOnRecState ()

bool	doWeakClustering ()
	INTERNAL Hooks to allow clustering W bosons.

bool	doSQCDClustering ()
	INTERNAL Hooks to allow clustering clustering of gluons to squarks.

double	muF ()
	Store / get first scale in PDF's that Pythia should have used.

double	muR ()

double	muFinME ()
	Store / get factorisation scale used in matrix element calculation. More...

double	muRinME ()

void	doIgnoreStep (bool doIgnoreIn)
	Functions to steer merging code. More...

void	storeWeights (vector< double > weight)
	Stored weights in case veto needs to be revoked.

void	setShowerStoppingScale (double scale=0.)

double	getShowerStoppingScale ()

void	nMinMPI (int nMinMPIIn)

int	nMinMPI ()

double	kTdurham (const Particle &RadAfterBranch, const Particle &EmtAfterBranch, int Type, double D)
	Functions for internal merging scale definions. More...

double	rhoPythia (const Event &event, int rad, int emt, int rec, int ShowerType)
	Function to compute "pythia pT separation" from Particle input. More...

int	findColour (int col, int iExclude1, int iExclude2, const Event &event, int type, bool isHardIn)

double	deltaRij (Vec4 jet1, Vec4 jet2)
	Function to compute Delta R separation from 4-vector input. More...

double	getWeightNLO (int i=0)
	Functions for weight management. More...

vector< double >	getWeightCKKWL ()
	Return CKKW-L weight.

vector< double >	getWeightFIRST ()
	Return O() weight.

void	setWeightCKKWL (vector< double > weightIn)
	Set CKKW-L weight.

void	setWeightFIRST (vector< double > weightIn)
	Set O() weight.

vector< double >	getSudakovWeight ()

vector< double >	getCouplingWeight ()
	Function to return coupling weight.

void	setEventVetoInfo (int nJetNowIn, double tmsNowIn)
	Functions and members to store the event veto information. More...

void	setHardProcessInfo (int nHardNowIn, double tmsHardNowIn)
	Set the hard process information.

void	addVetoInMainShower ()

int	getNumberVetoedInMainShower ()

Public Member Functions inherited from PhysicsBase
void	initInfoPtr (Info &infoPtrIn)
	This function is called from above for physics objects used in a run. More...

virtual	~PhysicsBase ()
	Empty virtual destructor.

bool	flag (string key) const
	Shorthand to read settings values.

int	mode (string key) const

double	parm (string key) const

string	word (string key) const

vector< bool >	fvec (string key) const

vector< int >	mvec (string key) const

vector< double >	pvec (string key) const

vector< string >	wvec (string key) const

Public Attributes
bool	doMOPSSave

bool	doMEMSave

Public Attributes inherited from MergingHooks
bool	useShowerPluginSave
	Functions used as clusterings / probabilities.

bool	useOwnHardProcess
	The members, switches etc. More...

HardProcess *	hardProcess

PartonLevel *	showers

AlphaStrong	AlphaS_FSRSave
	AlphaS objects for alphaS reweighting use.

AlphaStrong	AlphaS_ISRSave

AlphaEM	AlphaEM_FSRSave

AlphaEM	AlphaEM_ISRSave

string	lheInputFile
	Saved path to LHE file for more automated merging.

bool	doUserMergingSave
	Flags for merging procedure definition.

bool	doMGMergingSave

bool	doKTMergingSave

bool	doPTLundMergingSave

bool	doCutBasedMergingSave

bool	includeMassiveSave

bool	enforceStrongOrderingSave

bool	orderInRapiditySave

bool	pickByFullPSave

bool	pickByPoPT2Save

bool	includeRedundantSave

bool	pickBySumPTSave

bool	allowColourShufflingSave

bool	resetHardQRenSave

bool	resetHardQFacSave

int	unorderedScalePrescipSave

int	unorderedASscalePrescipSave

int	unorderedPDFscalePrescipSave

int	incompleteScalePrescipSave

int	ktTypeSave

int	nReclusterSave

int	nQuarksMergeSave

int	nRequestedSave

double	scaleSeparationFactorSave

double	nonJoinedNormSave

double	fsrInRecNormSave

double	herwigAcollFSRSave

double	herwigAcollISRSave

double	pT0ISRSave

double	pTcutSave

double	pTminISRSave

double	pTminFSRSave

bool	doNL3TreeSave

bool	doNL3LoopSave

bool	doNL3SubtSave

bool	doUNLOPSTreeSave

bool	doUNLOPSLoopSave

bool	doUNLOPSSubtSave

bool	doUNLOPSSubtNLOSave

bool	doUMEPSTreeSave

bool	doUMEPSSubtSave

bool	doEstimateXSection
	Flag to only do phase space cut, rejecting events below the tms cut.

bool	doRuntimeAMCATNLOInterfaceSave
	Flag for runtime aMC interface. Needed for aMC-Delta.

bool	applyVeto

Event	inputEvent
	Save input event in case decay products need to be detached.

vector< pair< int, int > >	resonances

bool	doRemoveDecayProducts

double	muMISave
	Starting scale for attaching MPI.

double	kFactor0jSave
	Precalculated K-factors.

double	kFactor1jSave

double	kFactor2jSave

double	tmsValueSave
	Saved members.

double	tmsValueNow

double	DparameterSave

int	nJetMaxSave

int	nJetMaxNLOSave

string	processSave

string	processNow

vector< double >	tmsListSave

bool	doOrderHistoriesSave

bool	doCutOnRecStateSave

bool	doWeakClusteringSave
	INTERNAL Hooks to allow clustering W bosons.

bool	doSQCDClusteringSave

double	muFSave
	Store / get first scale in PDF's that Pythia should have used.

double	muRSave

double	muFinMESave
	Store / get factorisation scale used in matrix element calculation.

double	muRinMESave

bool	doIgnoreEmissionsSave
	Flag to indicate trial shower usage.

bool	doIgnoreStepSave
	Flag to indicate if events should be vetoed.

double	pTsave
	Stored weights in case veot needs to be revoked.

vector< double >	weightCKKWL1Save

vector< double >	weightCKKWL2Save

int	nMinMPISave

vector< double >	weightCKKWLSave
	Save CKKW-L weight / O() weight.

vector< double >	weightFIRSTSave

IndividualWeights	individualWeights

bool	doVariations
	Flag to indicate whether renormalization scale variations are performed.

vector< double >	muRVarFactors
	Vector of variation factors applied to renormalization scale.

int	nWgts
	Number of weights, nominal + variations.

int	nJetMaxLocal
	Local copies of nJetMax inputs, if recalculation is necessary.

int	nJetMaxNLOLocal

bool	hasJetMaxLocal

bool	includeWGTinXSECSave

int	nHardNowSave

int	nJetNowSave

double	tmsHardNowSave

double	tmsNowSave

double	stopScaleSave

int	nVetoedInMainShower
	Statistics.

Protected Member Functions
void	doIgnoreStep (bool doIgnoreIn)
	Functions to steer merging code. More...

bool	canVetoStep ()
	Function to allow event veto.

double	rhoPythia (const Event &event, int rad, int emt, int rec, int ShowerType)
	Functions for internal merging scale definions. More...

int	findColour (int col, int iExclude1, int iExclude2, const Event &event, int type, bool isHardIn)

void	store ()

void	restore ()

Protected Member Functions inherited from PhysicsBase
	PhysicsBase ()
	Default constructor.

virtual void	onInitInfoPtr ()

virtual void	onBeginEvent ()
	This function is called in the very beginning of each Pythia::next call.

virtual void	onEndEvent (Status)

virtual void	onStat ()
	This function is called from the Pythia::stat() call.

void	registerSubObject (PhysicsBase &pb)
	Register a sub object that should have its information in sync with this.

Protected Attributes
bool	isInit

bool	isStored

int	nReclusterStore
	Member variables to store and restore to.

int	nRequestedStore

int	nJetMaxStore

int	nJetMaxNLOStore

int	nMinMPIStore

int	nJetMaxLocalStore

int	nJetMaxNLOLocalStore

int	nHardNowStore

int	nJetNowStore

double	pT0ISRStore

double	pTcutStore

double	muMIStore

double	tmsValueStore

double	tmsValueNowStore

double	DparameterStore

double	muFStore

double	muRStore

double	muFinMEStore

double	muRinMEStore

double	pTstore

double	tmsHardNowStore

double	tmsNowStore

bool	doOrderHistoriesStore

bool	doIgnoreEmissionsStore

bool	doIgnoreStepStore

bool	hasJetMaxLocalStore

Event	inputEventStore

vector< pair< int, int > >	resonancesStore

HardProcess	hardProcessStore

vector< double >	stoppingScalesSave

Protected Attributes inherited from PhysicsBase
Info *	infoPtr = {}

Settings *	settingsPtr = {}
	Pointer to the settings database.

ParticleData *	particleDataPtr = {}
	Pointer to the particle data table.

Logger *	loggerPtr = {}
	Pointer to logger.

HadronWidths *	hadronWidthsPtr = {}
	Pointer to the hadron widths data table.

Rndm *	rndmPtr = {}
	Pointer to the random number generator.

CoupSM *	coupSMPtr = {}
	Pointers to SM and SUSY couplings.

CoupSUSY *	coupSUSYPtr = {}

BeamSetup *	beamSetupPtr = {}

BeamParticle *	beamAPtr = {}

BeamParticle *	beamBPtr = {}

BeamParticle *	beamPomAPtr = {}

BeamParticle *	beamPomBPtr = {}

BeamParticle *	beamGamAPtr = {}

BeamParticle *	beamGamBPtr = {}

BeamParticle *	beamVMDAPtr = {}

BeamParticle *	beamVMDBPtr = {}

PartonSystems *	partonSystemsPtr = {}
	Pointer to information on subcollision parton locations.

SigmaTotal *	sigmaTotPtr = {}
	Pointers to the total/elastic/diffractive cross sections.

SigmaCombined *	sigmaCmbPtr = {}

set< PhysicsBase * >	subObjects

UserHooksPtr	userHooksPtr

Additional Inherited Members
Public Types inherited from PhysicsBase
enum	Status { INCOMPLETE = -1, COMPLETE = 0, CONSTRUCTOR_FAILED, INIT_FAILED, LHEF_END, LOWENERGY_FAILED, PROCESSLEVEL_FAILED, PROCESSLEVEL_USERVETO, MERGING_FAILED, PARTONLEVEL_FAILED, PARTONLEVEL_USERVETO, HADRONLEVEL_FAILED, CHECK_FAILED, OTHER_UNPHYSICAL, HEAVYION_FAILED, HADRONLEVEL_USERVETO }
	Enumerate the different status codes the event generation can have.

Detailed Description

DireMergingHooks is base class for user input to the merging procedure.

Member Function Documentation

bool checkAgainstCut ( const Particle & particle )

Functions used as default merging scales.

Function to check if the input particle is a light jet, i.e. should be checked against the merging scale defintion.

Function to check if the properties of the input particle should be checked against the cut-based merging scale defintion.

Do not check uncoloured particles.

By default, use u-, d-, c-, s- and b-quarks.

Done

void doIgnoreEmissions ( bool doIgnoreIn )

inline

Functions to steer shower evolution (public to allow for PS plugin).

Flag to indicate trial shower usage.

void doIgnoreStep ( bool doIgnoreIn )

inlineprotected

Functions to steer merging code.

Flag to indicate if events should be vetoed.

bool doVetoEmission ( const Event & event )

virtual

Function to check if emission should be rejected.

Do nothing in trial showers, or after first step.

Do nothing in CKKW-L

For NLO merging, count and veto emissions above the merging scale

Get number of clustering steps

Get merging scale in current event

Get maximal number of additional jets

Always remove emissions above the merging scale for samples containing reclusterings!

Check veto condition

Do not veto if state already includes MPI.

When performing NL3 merging of tree-level events, reset the CKKWL weight.

If the emission is allowed, do not check any further emissions

Done

Reimplemented from MergingHooks.

bool doVetoStep	(	const Event &	process,
		const Event &	event,
		bool	doResonance = `false`
	)

virtual

Function to check event veto.

Function to check if emission should be rejected.

Do nothing in trial showers, or after first step.

Do nothing in UMEPS or UNLOPS

Get number of clustering steps. If necessary, remove resonance decay products first.

Get maximal number of additional jets.

Get merging scale in current event.

Do not print zero-weight events. For non-resonant showers, simply check veto. If event should indeed be vetoed, save the current pT and weights in case the veto needs to be revoked.

Store pT to check if veto needs to be revoked later.

Store veto inputs to perform veto at a later stage. if (!applyVeto) { setEventVetoInfo(nSteps, tnow); return false; }

Check merging veto condition.

Set weight to zero if event should be vetoed.

Save weight before veto, in case veto needs to be revoked.

Reset stored weights.

Store veto inputs to perform veto at a later stage.

Done

For resonant showers, check if any previous veto should be revoked. This means we treat showers off resonance decay products identical to MPI: If a hard resonance emission has been produced, the event should have been kept. Following this reasoning, it might be necessary to revoke any previous veto.

Initialise switch to revoke vetoing.

Nothing to check if pTsave was not stored, i.e. no emission to possibly veto was recorded. Only allow revoking the veto for diboson processes, with resonant electroweak bosons

For hadronic resonance decays at hadron colliders, do not veto events with a hard emission of the resonance decay products, since such states are not included in the matrix element

Check how many resonance decay systems are allowed

Find systems really containing only emission off a resonance decay

Resonance decay systems are considered last, thus at the end of the list

Check the members of the resonance decay systems

Save the (three) members of the resonance decay system

Now find emitted gluon or gamma

Per system, only one emission

Revoke previous veto of last emission if a splitting of the resonance produced a harder parton, i.e. we are inside the PS region

Do nothing (i.e. allow other first emission veto) for soft splitting

Done with one system

Done with all systems

Check veto condition

Check veto condition.

Set stored weights to zero.

Now allow veto.

If the emission is allowed, do not check any further emissions

Done

Reimplemented from MergingHooks.

int findColour	(	int	col,
		int	iExclude1,
		int	iExclude2,
		const Event &	event,
		int	type,
		bool	isHardIn
	)

protected

Function to find a colour (anticolour) index in the input event, used to find colour-connected recoilers

Function to find a colour (anticolour) index in the input event. Helper for rhoms IN int col : Colour tag to be investigated int iExclude1 : Identifier of first particle to be excluded from search int iExclude2 : Identifier of second particle to be excluded from search Event event : event to be searched for colour tag int type : Tag to define if col should be counted as colour (type = 1) [->find anti-colour index contracted with col] anticolour (type = 2) [->find colour index contracted with col] OUT int : Position of particle in event record contraced with col [0 if col is free tag]

Search event record for matching colour & anticolour

Check outgoing

Check incoming

Search event record for matching colour & anticolour

Check outgoing from ISR

Check outgoing from FSR

first initial

second initial

if no matching colour / anticolour has been found, return false

int getNumberOfClusteringSteps	(	const Event &	event,
		bool	resetNjetMax = `false`
	)

virtual

Function to return the number of clustering steps for the current event.

Count the number of final state partons

Count the number of final state leptons

Add neutralinos to number of leptons

Add sleptons to number of leptons

Count the number of final state electroweak bosons

Return the difference to the core process outgoing particles

For inclusive handling, the number of reclustering steps can be different within a single sample.

Final particle counters

Set steps for QCD or QCD+QED events: Need at least two massless particles at lowest multiplicity.

Set steps for events containing heavy bosons. Need at least one massive particle at lowest multiplicity.

dynamical handling of steps

Return the difference to the core process outgoing particles

Reimplemented from MergingHooks.

void init ( )

virtual

The DireMergingHooks class.

Initialise DireMergingHooks class

Abuse init to store and restore state of MergingHooks.

Get core process from user input. Return if no process was selected.

Save pointers

Initialise AlphaS objects for reweighting

Initialise AlphaEM objects for reweighting

Initialise merging switches

Initialise automated MadGraph kT merging

Initialise kT merging

Initialise evolution-pT merging

Initialise {ij}, pT_i Q_{ij} merging

Initialise exact definition of kT

Initialise NL3 switches.

Initialise UNLOPS switches.

Initialise UMEPS switches

Flag to only do phase space cut.

Flag to check if merging weight should directly be included in the cross section.

Flag to check if CKKW-L event veto should be applied.

Clear hard process

Initialise input event.

Initialise the hard process

Parameters for reconstruction of evolution scales

Parameters for choosing history probabilistically

Parameters for scale choices

Parameter for allowing swapping of one colour index while reclustering

Parameters to allow setting hard process scales to default (dynamical) Pythia values.

Parameters for choosing history by sum(|pT|)

Information on the shower cut-off scale

Initialise CKKWL weight

Initialise merging scale

Save merging scale on maximal number of jets

Read merging scale (defined in kT) from input parameter.

Read merging scale (defined in kT) from LHE file.

Save list of cuts defining the merging scale.

Write tms cut values to list of cut values, ordered by DeltaR_{ij}, pT_{i}, Q_{ij}.

Read additional settingsPtr->for NLO merging methods.

Internal Pythia cross section should not include NLO merging weights.

Check if external shower plugin should be used.

Write banner.

Reimplemented from MergingHooks.

double rhoPythia	(	const Event &	event,
		int	rad,
		int	emt,
		int	rec,
		int	ShowerType
	)

protected

Functions for internal merging scale definions.

Function to compute "pythia pT separation" from Particle input

Function to compute "pythia pT separation" from Particle input, as a helper for rhoms(...).

Use external shower for merging. Ask showers for evolution variable.

double scalems ( const Event & event )

Find the minimal Lund pT between coloured partons in the event double scalems( const Event& event, bool withColour);

Find the minimal Lund pT between coloured partons in the input event. If doPTLundMerging = true, this function will be used as a merging scale definition.

Only check first emission.

Find all electroweak decayed bosons in the state.

Declare final parton vectors

Search inEvent record for final state partons. Exclude decay products of ew resonance.

Except for e+e- -> jets, do not check radiation in resonance decays.

Include photons into the tms definition for "weak+QCD merging".

Include Z-bosons into the tms definition for "weak+QCD merging".

Include W-bosons into the tms definition for "weak+QCD merging".

Get index of first incoming

Get index of second incoming

If no incoming of the cascade are found, try incoming

Find current incoming partons

For pure QCD set the cut to the pT of the dijet system.

No cut if only massive particles in final state.

Find minimal pythia pt in event

Compute II separation of i-emission and first incoming as radiator

Compute II separation of i-emission and second incoming as radiator

Compute all IF separations of i-emission and first incoming as radiator

Allow both initial partons as recoiler

Check with first initial as recoiler

Compute all IF separations of i-emission and second incoming as radiator

Allow both initial partons as recoiler

Check with first initial as recoiler

Compute all FF separations between final state partons.

Allow any parton as recoiler

Compute pythia FSR separation between two jets, with eith initial as recoiler.

Allow both initial partons as recoiler

Check with first initial as recoiler

Compute pythia FSR separation between two jets, with eith initial as recoiler.

Allow both initial partons as recoiler

Check with second initial as recoiler

Reset minimal y separation

bool setShowerStartingScales	(	bool	isTrial,
		bool	doMergeFirstEmm,
		double &	pTscaleIn,
		const Event &	event,
		double &	pTmaxFSRIn,
		bool &	limitPTmaxFSRIn,
		double &	pTmaxISRIn,
		bool &	limitPTmaxISRIn,
		double &	pTmaxMPIIn,
		bool &	limitPTmaxMPIIn
	)

virtual

Set starting scales.

Function to set the correct starting scales of the shower. Note: 2 -> 2 QCD systems can be produced by MPI. Hence, there is an overlap between MPI and "hard" 2 -> 2 QCD systems which needs to be removed by no-MPI probabilities. This means that for any "hard" 2 -> 2 QCD system, multiparton interactions should start at the maximal scale of multiple interactions. The same argument holds for any "hard" process that overlaps with MPI.

Local copies of power/wimpy shower booleans and scales.

Merging of EW+QCD showers with matrix elements: Ensure that

any event with more than one final state particle will be showered from the reconstructed transverse momentum of the last emission, even if the factorisation scale is low.
the shower starting scale for events with no emission is given by the (user-defined) choice.

Check if the process only contains two outgoing partons. If so, then this process could also have been produced by MPI. Thus, the MPI starting scale would need to be set accordingly to correctly attach a "no-MPI-probability" to multi-jet events. ("Hard" MPI are included by not restricting MPI when showering the lowest-multiplicity sample.)

SET THE STARTING SCALES FOR TRIAL SHOWERS.

Reset shower and MPI scales.

Reset to minimal scale for wimpy showers. Keep scales for EW+QCD merging.

For EW+QCD merging, apply wimpy shower only to 2->1 processes.

For pure QCD set the PS starting scales to the pT of the dijet system.

If necessary, set the MPI starting scale to the collider energy.

Reset phase space limitation flags

If necessary, set the MPI starting scale to the collider energy.

SET THE STARTING SCALES FOR REGULAR SHOWERS.

Remember if this is a "regular" shower off a reclustered event.

Reset shower and MPI scales.

Reset to minimal scale for wimpy showers. Keep scales for EW+QCD merging.

For EW+QCD merging, apply wimpy shower only to 2->1 processes.

For pure QCD set the PS starting scales to the pT of the dijet system.

If necessary, set the MPI starting scale to the collider energy.

For reclustered events, no-MPI-probability between "pTmaxMPI" and "scale" already included in the event weight.

Reset power/wimpy shower switches iand scales if necessary.

Done

Reimplemented from MergingHooks.

double tmsNow ( const Event & event )

virtual

Function to return the value of the merging scale function in the current event.

Get merging scale in current event.

tnow = scalems(event, false);

Return merging scale value. Done

Reimplemented from MergingHooks.

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

include/Pythia8/DireMergingHooks.h
src/DireMergingHooks.cc

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