ThePEG  1.8.0
Static Public Member Functions | Protected Attributes | Private Member Functions | Static Private Attributes
ThePEG::MEee2gZ2qq Class Reference

The MEee2gZ2qq class implements the $e^+e^-\rightarrow\gamma/Z^0\rightarrow q\bar{q}$ matrix element. More...

#include <MEee2gZ2qq.h>

Inheritance diagram for ThePEG::MEee2gZ2qq:
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List of all members.

Public Member Functions

Standard constructors and destructors.
 MEee2gZ2qq ()
 Default constructor.
Virtual functions required by the MEBase class.
virtual unsigned int orderInAlphaS () const
 Return the order in $\alpha_S$ in which this matrix element is given.
virtual unsigned int orderInAlphaEW () const
 Return the order in $\alpha_{EM}$ in which this matrix element is given.
virtual double me2 () const
 The matrix element for the kinematical configuration previously provided by the last call to setKinematics(), suitably scaled by sHat() to give a dimension-less number.
virtual void getDiagrams () const
 Add all possible diagrams with the add() function.
virtual Selector< const
ColourLines * > 
colourGeometries (tcDiagPtr diag) const
 Return a Selector with possible colour geometries for the selected diagram weighted by their relative probabilities.
virtual Selector< DiagramIndexdiagrams (const DiagramVector &dv) const
 Get diagram selector.
virtual Energy2 scale () const
 Return the scale associated with the last set phase space point.
Functions used by the persistent I/O system.
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently.
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently.
- Public Member Functions inherited from ThePEG::ME2to2QCD
 ME2to2QCD ()
 Default constructor.
virtual ~ME2to2QCD ()
 Destructor.
double comfac () const
 The common prefactor for all 2 $\rightarrow$ 2 QCD sub-processes ie.
int maxFlavour () const
 Return the heaviest flavour allowed for this matrix element.
double Kfac () const
 K-factor for artificially boosting the cross-section.
double KfacA () const
 K-factor for artificially boosting colour-annihilation diagrams.
bool interference () const
 Return true if interference terms should be used.
bool isQuark (const ParticleData &p) const
 Return true if argument is a quark.
tcPDPtr quark (int i) const
 Return the quark with flavour i (or gluon if i = 0);.
- Public Member Functions inherited from ThePEG::ME2to2Base
virtual double getCosTheta (double cthmin, double cthmax, const double *r)
 Used internally by generateKinematics, after calculating the limits on cos(theta).
int scaleChoice () const
 Give the option corresponding to the way the scale of an interaction is calculated.
 ME2to2Base ()
 Default constructor.
virtual ~ME2to2Base ()
 Destructor.
virtual int nDim () const
 The number of internal degreed of freedom used in the matrix element.
virtual bool generateKinematics (const double *r)
 Generate internal degrees of freedom given 'nDim()' uniform random numbers in the interval ]0,1[.
virtual CrossSection dSigHatDR () const
 Return the matrix element for the kinematical configuation previously provided by the last call to setKinematics().
virtual void setKinematics ()
 Set the typed and momenta of the incoming and outgoing partons to be used in subsequent calls to me() and colourGeometries() according to the associated XComb object.
Energy2 tHat () const
 Return the $\hat{t}$ of the last set phase space point.
Energy2 uHat () const
 Return the $\hat{u}$ of the last set phase space point.
double phi () const
 Return the azimuth angle of the last set phase space point.
- Public Member Functions inherited from ThePEG::MEBase
 MEBase ()
 Default constructor.
virtual ~MEBase ()
 Destructor.
virtual double alphaS () const
 Return the value of $\alpha_S$ associated with the phase space point provided by the last call to setKinematics().
virtual double alphaEM () const
 Return the value of $\alpha_EM$ associated with the phase space point provided by the last call to setKinematics().
void setKinematics (tPPair in, const PVector &out)
 Set the typed and momenta of the incoming and outgoing partons to be used in subsequent calls to me() and colourGeometries().
virtual void constructVertex (tSubProPtr sub)
 construct the spin information for the interaction
virtual bool wantCMS () const
 Return true, if this matrix element expects the incoming partons in their center-of-mass system.
virtual bool headCuts () const
 If this is a dependent matrix element in a ME group, return true, if cuts should be inherited from the head matrix element, i.e.
virtual bool ignoreCuts () const
 If this is a dependent matrix element in a ME group, return true, if cuts should be ignored.
virtual bool apply () const
 If this is a dependent matrix element in a ME group, return true, if it applies to the process set in lastXComb()
virtual bool haveX1X2 () const
 Return true, if this matrix element will generate momenta for the incoming partons itself.
virtual bool havePDFWeight1 () const
 Return true, if this matrix element provides the PDF weight for the first incoming parton itself.
virtual bool havePDFWeight2 () const
 Return true, if this matrix element provides the PDF weight for the second incoming parton itself.
virtual bool keepRandomNumbers () const
 Return true, if the XComb steering this matrix element should keep track of the random numbers used to generate the last phase space point.
virtual void generateSubCollision (SubProcess &)
 Comlete a SubProcess object using the internal degrees of freedom generated in the last generateKinematics() (and possible other degrees of freedom which was intergated over in dSigHatDR().
virtual void clearKinematics ()
 Clear the information previously provided by a call to setKinematics(...).
virtual bool noMirror () const
 Return true, if this matrix element does not want to make use of mirroring processes; in this case all possible partonic subprocesses with a fixed assignment of incoming particles need to be provided through the diagrams added with the add(...) method.
const DiagramVectordiagrams () const
 Return all possible diagrams.
virtual const ColourLinesselectColourGeometry (tcDiagPtr diag) const
 Select a ColpurLines geometry.
virtual DiagramIndex diagram (const DiagramVector &) const
 Select a diagram.
bool reweighted () const
 Return true if this matrix element has associated (p)reWeight objects assigned.
double reWeight () const
 With the information previously supplied with the setKinematics(...) methods, return the combined effects of the reweighters.
double preWeight () const
 With the information previously supplied with the setKinematics(...) methods, return the comined effects of the peweighters.
void addReweighter (tReweightPtr rw)
 Add objects to the list of reweighters.
void addPreweighter (tReweightPtr rw)
 Add objects to the list of preweighters.
Ptr< Amplitude >::pointer amplitude () const
 Return the amplitude associated with this matrix element.
void amplitude (Ptr< Amplitude >::pointer amp)
 Set the amplitude associated with this matrix element.
Energy2 sHat () const
 Return the last set invariant mass squared.
double preweight () const
 Return the factor with which this matrix element was last pre-weighted.
virtual void flushCaches ()
 Inform this matrix element that a new phase space point is about to be generated, so all caches should be flushed.
virtual void setXComb (tStdXCombPtr)
 Set the XComb object to be used in the next call to generateKinematics() and dSigHatDR().
const DVectormeInfo () const
 Retrieve information obtained in the calculation of the cross section to be used later when selecting diagrams and colour flow.
void meInfo (const DVector &info) const
 Save information obtained in the calculation of the cross section to be used later when selecting diagrams and colour flow.
int maxMultCKKW () const
 If this matrix element is to be used together with others for CKKW reweighting and veto, this should give the multiplicity of outgoing particles in the highest multiplicity matrix element in the group.
int minMultCKKW () const
 If this matrix element is to be used together with others for CKKW reweighting and veto, this should give the multiplicity of outgoing particles in the lowest multiplicity matrix element in the group.
virtual void setVetoScales (tSubProPtr) const
 Set veto scales on the particles at the given SubProcess which has been generated using this matrix element.
- Public Member Functions inherited from ThePEG::LastXCombInfo< StandardXComb >
const StandardXComblastXComb () const
 Return a reference to the last selected XComb.
tXCPtr lastXCombPtr () const
 Return a pointer to the last selected XComb.
const StandardXComblastHeadXComb () const
 If the last selected XComb object belongs to a group of XComb's return a reference to the head XComb object for this group.
tXCPtr lastHeadXCombPtr () const
 If the last selected XComb object belongs to a group of XComb's return a pointer to the head XComb object for this group.
const EventHandlerlastEventHandler () const
 Return a reference to the currently used EventHandler.
tPExtrPtr lastExtractor () const
 A pointer to the currently used parton extractor.
PDFT pdf (tcPPtr parton) const
 Return the parton density used to extract the given parton.
const CutslastCuts () const
 A reference to the currently used kinematical cuts.
tCutsPtr lastCutsPtr () const
 A pointer to the currently used kinematical cuts.
const PPairlastParticles () const
 Return the pair of incoming parton instances.
Energy2 lastS () const
 The last generated total energy squared of the incoming particles.
const PPairlastPartons () const
 Return the pair of incoming parton instances.
Energy2 lastSHat () const
 The last used interval in total parton-parton energy squared.
double lastTau () const
 Return lastSHat()/lastS().
double lastY () const
 The generated rapidity of the hard scattering sub-system.
double lastP1 () const
 Log of one over the momentum fraction of the first incoming particle w.r.t.
double lastP2 () const
 Log of one over the momentum fraction of the second incoming particle w.r.t.
double lastL1 () const
 Log of one over the first incoming parton momentum fraction w.r.t.
double lastL2 () const
 Log of one over the second incoming parton momentum fraction w.r.t.
double lastX1 () const
 The first incoming parton momentum fraction w.r.t.
double lastX2 () const
 The second incoming parton momentum fraction w.r.t.
double lastE1 () const
 Return 1-lastX1() to highest possible precision for x $\rightarrow$ 1.
double lastE2 () const
 Return 1-lastX2() to highest possible precision for x $\rightarrow$ 1.
double lastFL1L2 () const
 The product of the parton density functions at the last generated phase-space point.
Energy2 lastScale () const
 The chosen scale of the hard scattering.
double lastAlphaS () const
 Get the $\alpha_S$ used in the hard scattering.
double lastAlphaEM () const
 Get the $\alpha_{EM}$ used in the hard scattering.
const vector< Lorentz5Momentum > & meMomenta () const
 Return the momenta of the incoming and outgoing partons to be used by the matrix element object, in the order specified by the TreeDiagram objects given by the matrix element.
double lastME2 () const
 Return the matrix element squared as calculated for the last phase space point.
double jacobian () const
 Get the last jacobian obtained when generating the kinematics for the call to dSigHatDR.
CrossSection lastMECrossSection () const
 Return the partonic cross section as calculated for the last phase space point.
double lastMEPDFWeight () const
 Return the PDF weight as calculated for the last phase space point, if the matrix element does supply PDF weights.
tSubProPtr subProcess () const
 Return the SubProcess object corresponding to the last generated sub-process.
const cPDVectormePartonData () const
 Return the incoming and outgoing parton types to be used by the matrix element object, in the order specified by the TreeDiagram objects given by the matrix element.

Static Public Member Functions

static void Init ()
 Standard Init function used to initialize the interface.

Protected Member Functions

Clone Methods.
virtual IBPtr clone () const
 Make a simple clone of this object.
virtual IBPtr fullclone () const
 Make a clone of this object, possibly modifying the cloned object to make it sane.
Standard Interfaced functions.
virtual void doinit ()
 Initialize this object after the setup phase before saving an EventGenerator to disk.

Protected Attributes

vector< double > coefs
 Constants for the different terms set from the StandardModel in the init() function.
Energy2 mZ2
 The squared mass of the Z0.
Energy2 GZ2
 The squared width of the Z0.
double lastCont
 The last continuum term to be used to select primary diagram.
double lastBW
 The last Breit-Wigner term to be used to select primary diagram.

Private Member Functions

MEee2gZ2qqoperator= (const MEee2gZ2qq &)
 Private and non-existent assignment operator.

Static Private Attributes

static ClassDescription
< MEee2gZ2qq
initMEee2gZ2qq
 Describe a concrete class with persistent data.

Detailed Description

The MEee2gZ2qq class implements the $e^+e^-\rightarrow\gamma/Z^0\rightarrow q\bar{q}$ matrix element.

Both the continuum and $Z^0$ pole term as well as the interference term is included. Although not a strict QCD matrix element the class inherits from ME2to2QCD, mainly to inherit the parameter for the number of active quark flavours.

See also:
The interfaces defined for MEee2gZ2qq.
ME2to2QCD

Definition at line 29 of file MEee2gZ2qq.h.


Member Function Documentation

virtual IBPtr ThePEG::MEee2gZ2qq::clone ( ) const
protectedvirtual

Make a simple clone of this object.

Returns:
a pointer to the new object.

Implements ThePEG::InterfacedBase.

virtual Selector<const ColourLines *> ThePEG::MEee2gZ2qq::colourGeometries ( tcDiagPtr  diag) const
virtual

Return a Selector with possible colour geometries for the selected diagram weighted by their relative probabilities.

Parameters:
diagthe diagram chosen.
Returns:
the possible colour geometries weighted by their relative probabilities.

Implements ThePEG::MEBase.

virtual Selector<DiagramIndex> ThePEG::MEee2gZ2qq::diagrams ( const DiagramVector dv) const
virtual

Get diagram selector.

With the information previously supplied with the setKinematics method, a derived class may optionally override this method to weight the given diagrams with their (although certainly not physical) relative probabilities.

Parameters:
dvthe diagrams to be weighted.
Returns:
a Selector relating the given diagrams to their weights.

Reimplemented from ThePEG::MEBase.

virtual void ThePEG::MEee2gZ2qq::doinit ( )
protectedvirtual

Initialize this object after the setup phase before saving an EventGenerator to disk.

Exceptions:
InitExceptionif object could not be initialized properly.

Reimplemented from ThePEG::InterfacedBase.

virtual IBPtr ThePEG::MEee2gZ2qq::fullclone ( ) const
protectedvirtual

Make a clone of this object, possibly modifying the cloned object to make it sane.

Returns:
a pointer to the new object.

Reimplemented from ThePEG::InterfacedBase.

virtual double ThePEG::MEee2gZ2qq::me2 ( ) const
virtual

The matrix element for the kinematical configuration previously provided by the last call to setKinematics(), suitably scaled by sHat() to give a dimension-less number.

Returns:
the matrix element scaled with sHat() to give a dimensionless number.

Implements ThePEG::MEBase.

virtual unsigned int ThePEG::MEee2gZ2qq::orderInAlphaEW ( ) const
virtual

Return the order in $\alpha_{EM}$ in which this matrix element is given.

Returns 2.

Reimplemented from ThePEG::ME2to2QCD.

virtual unsigned int ThePEG::MEee2gZ2qq::orderInAlphaS ( ) const
virtual

Return the order in $\alpha_S$ in which this matrix element is given.

Returns .

Reimplemented from ThePEG::ME2to2QCD.

void ThePEG::MEee2gZ2qq::persistentInput ( PersistentIStream is,
int  version 
)

Function used to read in object persistently.

Parameters:
isthe persistent input stream read from.
versionthe version number of the object when written.

Reimplemented from ThePEG::ME2to2QCD.

void ThePEG::MEee2gZ2qq::persistentOutput ( PersistentOStream os) const

Function used to write out object persistently.

Parameters:
osthe persistent output stream written to.

Reimplemented from ThePEG::ME2to2QCD.


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