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 $\Gamma$ variable of the endpoint vertex.
Energy2 Gamma () const
 Get the $\Gamma$ variable of the endpoint vertex.
EndPointoperator= (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 $\Gamma$ variable of the endpoint vertex.

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

Energy2 Pythia7::EndPoint::Gamma (  )  const [inline]

Get the $\Gamma$ variable of the endpoint vertex.

$\Gamma$ 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:

Generated on Thu Apr 29 12:45:34 2010 for Pythia7 by  doxygen 1.5.5