ColourFlow Class Reference

#include <VinciaHistory.h>

Public Member Functions
	ColourFlow ()
	Constructor.
void	addChain (int charge, int flavStart, int flavEnd, bool hasInitialIn)
	Methods. More...
void	selectResChains (int index, int iorder, int id)
	Select a chains. More...
void	selectBeamChains (int index, int iorder)
	Add beam chains. More...
bool	initHard (map< int, map< int, int > > &countRes, shared_ptr< VinciaMergingHooks > vinMergingHooksPtr)
	Initialise from hard process information. More...
bool	checkChains (int cIndex)
	Get information about current status of (pseudo)chains. More...
bool	checkChains ()
	Check we have enough chains. More...
int	getNChainsLeft ()
	Return number of unassigned chains.
int	maxLength ()
	Return maximum length next pseudochain selection. More...
int	minLength ()
	Return minimum length next pseudochain selection.
void	print (bool printpsch=false)
	Print information about (pseudo)chains. More...

Public Attributes
map< int, vector< PseudoChain > >	resChains
	Members. More...
vector< PseudoChain >	beamChains
	Remaining list of ordered chains after resonances stripped off.
map< int, vector< PseudoChain > >	pseudochains
map< int, vector< int > >	chainToIndices
map< int, int >	chainStartToFlav
	Map from chain to the flavour at the start or end of that chain.
map< int, int >	chainEndToFlav
map< int, bool >	hasInitial
	Keep track of chains which contain an initial state parton.
map< int, int >	chainToCharge
	Keep track of charge information of chains.

Detailed Description

A class for associating disconnected colour chains with either resonances or the hard QCD scattering. Once fixed, the sector history is deterministic.

Member Function Documentation

void addChain	(	int	charge,
		int	flavStart,
		int	flavEnd,
		bool	hasInitialIn
	)

Methods.

The ColourFlow class.

Add or assign chains.

Method to initialise neutral(/plus/minus) chains.

Save info about this chain.

Index (to look up pseudochain). Base Index = 2^iChain.

ChargeIndex = 0,1,2,3.

Create a new pseudochain with a single entry.

Save this pseudochain using chargeIndex and baseIndex.

Increment counter.

Save id.

Keep track of indices.

Insert in all possible ways into existing pseudochains. (But skip this step if gluon loop).

Loop over all existing pseudochains.

Insert in all possible ways.

Did we create any new pseudochains?

Save as used.

Check which other chains were in this pseudochain.

Convert index to binary.

Odd at this power? ==> contains ichain

Go to next power.

End loop over existing pseudochains.

For flavour-changing chains, try to make new connections.

Loop over all existing chains.

Insert into new pseudochains in all possible ways.

Don't add a chain to a pseudochain that already contains it.

Did we create any new pseudochains?

Save as used.

Check which other chains were in this pseudochain.

Convert index to binary.

Odd at this power? ==> contains ichain

Go to next power.

End loop over existing pseudochains.

Save all pseudochain indices which this chain is in.

Done.

bool checkChains

(

int

cIndex

)

Get information about current status of (pseudo)chains.

Check we have enough chains.

bool checkChains

(

)

Check we have enough chains.

How many still left to assign?

Do we have enough?

bool initHard	(	map< int, map< int, int > > &	countRes,
		shared_ptr< VinciaMergingHooks >	vinMergingHooksPtr
	)

Initialise from hard process information.

Get hadronically decaying resonances.

Count each type of resonance (need to know how many identical) and initialise resChains map.

int maxLength

(

)

Return maximum length next pseudochain selection.

How many beam chains still to select.

void print

(

bool

printpsch = false

)

Print information about (pseudo)chains.

Print the colour flow.

void selectBeamChains	(	int	index,
		int	iorder
	)

Add beam chains.

Fetch the selected pseudochain.

Save selection.

Remove selected chains from list of available ones.

void selectResChains	(	int	index,
		int	iorder,
		int	id
	)

Select a chains.

Fetch the selected pseudochain.

Save selection.

Update counters.

Remove selected chains from list of available ones.

Member Data Documentation

map<int,vector<int> > chainToIndices

Easy way to look up all pseudochains which contain a given chain. Map from chain number to pseudochain index.

map< int , vector< PseudoChain > > pseudochains

Maps to all viable combinations of chains (of each charge) from an index which depends on the identities of chains in it

• will be empty when resChains and beamChains set.

map<int, vector<PseudoChain> > resChains

Members.

Chains that arise from the decay of a resonance.

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

• include/Pythia8/VinciaHistory.h
• src/VinciaHistory.cc