ColConfig Class Reference

The ColConfig class describes the colour configuration of the whole event. More...

#include <FragmentationSystems.h>

Public Member Functions
	ColConfig ()
	Constructor.
void	init (Info *infoPtrIn, StringFlav *flavSelPtrIn)
	Initialize and save pointers. More...
int	size () const
	Number of colour singlets.
ColSinglet &	operator[] (int iSub)
	Overload index operator to access separate colour singlets.
const ColSinglet &	operator[] (int iSub) const
void	clear ()
	Clear contents.
bool	insert (vector< int > &iPartonIn, Event &event)
bool	simpleInsert (vector< int > &iPartonIn, Event &event, bool fixOrder=false)
void	erase (int iSub)
	Erase a colour singlet system. (Rare operation.)
void	collect (int iSub, Event &event, bool skipTrivial=true)
	Collect all partons of singlet to be consecutively ordered. More...
int	findSinglet (int i)
	Find to which singlet system a particle belongs. More...
void	list () const
	List all currently identified singlets. More...

Public Attributes
vector< vector< pair< double, double > > >	rapPairs

Detailed Description

The ColConfig class describes the colour configuration of the whole event.

Member Function Documentation

void collect	(	int	iSub,
		Event &	event,
		bool	skipTrivial = true
	)

Collect all partons of singlet to be consecutively ordered.

Check that all partons have positive energy.

Partons may already have been collected, e.g. at ministring collapse.

Check if partons already "by chance" happen to be ordered.

Normally done if in order, but sometimes may need to copy anyway.

Copy down system. Update current partons.

Done.

int findSinglet

(

int

i

)

Find to which singlet system a particle belongs.

Loop through all systems and all members in them.

Done without having found particle; return -1 = error code.

void init	(	Info *	infoPtrIn,
		StringFlav *	flavSelPtrIn
	)

Initialize and save pointers.

Save pointers.

Joining of nearby partons along the string.

For consistency ensure that mJoin is bigger than in StringRegion.

Simplification of q q q junction topology to quark - diquark one.

bool insert	(	vector< int > &	iPartonIn,
		Event &	event
	)

Insert a new colour singlet system in ascending mass order. Calculate its properties. Join nearby partons.

Find momentum and invariant mass of system, minus endpoint masses.

Check for rare triple- and higher junction systems (like J-Jbar-J)

Check that junction systems have at least three legs.

Check that momenta do not contain not-a-number.

Identify closed gluon loop. Assign "endpoint" masses as light quarks.

For junction topology: join two nearby legs into a diquark.

Loop while > 2 partons left and hope of finding joining pair.

Look for the pair of neighbour partons (along string) with the smallest invariant mass (subtracting quark masses).

Keep three legs of junction separate.

Avoid joining non-partons, e.g. gluino/squark for R-hadron.

If sufficiently nearby then join into one new parton. Note: error sensitivity to mJoin indicates unstable precedure??

When g + q -> q flip to ensure that mother1 = q.

Need to keep status as 74 for junctions in order to keep track of them.

Append joined parton to event record.

Displaced lifetime/vertex; mothers should be same but prefer quark.

Mark joined partons and reduce remaining system.

If joined,then loopback to look for more.

Store new colour singlet system at the end.

Now move around, so that smallest mass excesses come first.

Done.

void list

(

)

const

List all currently identified singlets.

Header. Loop over all individual singlets.

List all partons belonging to each singlet.

Done.

bool simpleInsert	(	vector< int > &	iPartonIn,
		Event &	event,
		bool	fixOrder = false
	)

Insert a new qqbar colour singlet system in ascending mass order. Calculate its properties.

Insert a new qqbar colour singlet system in ascending mass order. Simple version for at most two triplet-antitriplet systems.

Find momentum and invariant mass of system, minus endpoint masses.

Store new colour singlet system at the end.

If necessary flip so that smallest mass excesses come first.

Done.

Member Data Documentation

vector< vector< pair<double,double> > > rapPairs

Rapidity range [y_min, y_max] of all string pieces in all singlets. Only used when ClosePacking:doClosePacking is on.

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

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