Pythia7::EndPoint Class Reference

The EndPoint is the main helper class used by the LundFragHandler to handle the steps in the fragmentation procedure. More...

#include <EndPoint.h>

List of all members.

Standard constructors and destructors.
cPDPtr	theParticle
	The particle type at this endpoint.
cStringRegionPtr	theStrRg
	The current string region.
TransverseMomentum	thePTcomp
	The transverse momentum components of the particle.
Energy2	theGamma
	The invariant-time square.
	EndPoint ()
	The default constructor.
	EndPoint (const EndPoint &)
	The copy constructor.
	EndPoint (cPDPtr inPDPtr, cStringRegionPtr inSRPtr)
	Create an EndPoint given the type () of the particle standing at this endpoint and the string region of the break point.
	~EndPoint ()
	The destructor.
void	Init ()
	Reset this EndPoint to the default values.
void	Init (cPDPtr inPDPtr, cStringRegionPtr inSRPtr)
	Reset this EndPoint's ParticleData and StringRegion.
EndPoint	CC () const
	Return the charge conjugate of this EndPoint.
void	stepUp ()
	Stepping Method to move the EndPoint particle through the different string regions of the String representation.
void	stepDown ()
	Stepping Methods to move the EndPoint particle through the different string regions of the String representation.
void	UpdatedFrom (const EndPoint &currEP)
	Update this EndPoint given the current EndPoint (currEP).
cStringRegionPtr	SR () const
	Get the pointer to the StringRegion where this EndPoint is standing during the fragmentation process.
void	SR (cStringRegionPtr newSR)
	Set the pointer to the StringRegion where this EndPoint is standing during the fragmentation process.
const LorentzMomentum &	Pfwd () const
	Get the forward light-cone vector of the current StringRegion of this EndPoint.
const LorentzMomentum &	Pbwd () const
	Get the backward light-cone vector of the current StringRegion of this EndPoint.
double	Xremf () const
	Get the remaining forward momentum fraction of the current StringRegion of this EndPoint.
double	Xremb () const
	Get the remaining backward momentum fraction of the current StringRegion of this EndPoint.
void	PData (cPDPtr pd)
	Set the ParticleData pointer at this EndPoint.
cPDPtr	PData () const
	Get the ParticleData pointer at this EndPoint.
Energy	mass () const
	Return the constituent mass of the Particle at this EndPoint.
void	setPt (const TransverseMomentum &newPT)
	Set the transverse momentum components of the Particle at this EndPoint.
void	setPt (Energy px, Energy py)
	Set the transverse momentum components of the Particle at this EndPoint.
const TransverseMomentum &	pTcomp () const
	Get the transverse momentum components of the Particle at this EndPoint.
Energy	Px () const
	Get the transverse momentum components of the Particle at this EndPoint.
Energy	Py () const
	Get the transverse momentum components of the Particle at this EndPoint.
LorentzMomentum	pT () const
	Return the transverse 4-vector of the endpoint particle in the current string region.
void	Gamma (Energy2)
	Set the variable of the endpoint vertex.
Energy2	Gamma () const
	Get the variable of the endpoint vertex.
EndPoint &	operator= (const EndPoint &ep)
	EndPoint assigment operator.
void	echo () const
	Print info to cout for debugging purposes.
StringPtr	theString ()
	Get the pointer to the string being fragmented.

---

Detailed Description

The EndPoint is the main helper class used by the LundFragHandler to handle the steps in the fragmentation procedure.

The endpoint describes the quark (diquark) of a quark-antiquark (diquark-antidiquark) pair created at a breakpoint during the string fragmentation. At each step a new Hadron is created joining the newly created EndPoint with the old EndPoint left over at the previous step in the iterative procedure.

The information about the particle type are accessed through a pointer to the ParticleData object.

Conventions of the stepping methods :
stepUp() and stepDown() are the Oriented methods to move an EndPoint through the grid of the StringRegions. Internally the EndPoint's StringRegion is defined in the grid by its (j,k) indices. Assume an EndPoint ep standing in the (ji, ki):
then if a step is taken from the right side of the string :
ep.stepUp() will move it to the region (ji, ki+1) while ep.stepDown() to the region (ji+1, ki).
If a step is taken from the left side:
ep.stepUp() will now move it to the region (ji-1, ki) and ep.stepDown() to the region (ji, ki-1)

Apart of the pointer to the StringRegion, the step methods do not change any other members of the EndPoint.

See also:

String

StringRegion

LundFragHandler

Oriented

Definition at line 53 of file EndPoint.h.

---

Member Function Documentation

void Pythia7::EndPoint::UpdatedFrom

(

const EndPoint &

currEP

)

Update this EndPoint given the current EndPoint (currEP).

[At the end of a step the current EndPoint becomes the last EndPoint for the next step.]

void Pythia7::EndPoint::Gamma

(

Energy2

)

[inline]

Set the variable of the endpoint vertex.

represents the invariant-time squared from the vertex of the old EndPoint to this one

Energy2 Pythia7::EndPoint::Gamma

(

)

const [inline]

Get the variable of the endpoint vertex.

represents the invariant-time squared from the vertex of the old EndPoint to this one

---

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

• EndPoint.h