Herwig++
2.7.0
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The MEPP2GammaGamma class implements the production of photon pairs in hadron hadron collisions. More...
#include <MEPP2GammaGamma.h>
Public Member Functions | |
MEPP2GammaGamma () | |
The default constructor. | |
Virtual functions required by the MEBase class. | |
virtual unsigned int | orderInAlphaS () const |
Return the order in ![]() | |
virtual unsigned int | orderInAlphaEW () const |
Return the order in ![]() | |
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 Energy2 | scale () const |
Return the scale associated with the last set phase space point. | |
virtual void | getDiagrams () const |
Add all possible diagrams with the add() function. | |
virtual Selector< DiagramIndex > | diagrams (const DiagramVector &dv) const |
Get diagram selector. | |
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 void | constructVertex (tSubProPtr) |
Construct the vertex of spin correlations. | |
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. | |
Static Public Member Functions | |
static void | Init () |
The standard Init function used to initialize the interfaces. | |
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. | |
Private Member Functions | |
Complex | ggme (Energy2 s, Energy2 t, Energy2 u) const |
![]() ![]() | |
MEPP2GammaGamma & | operator= (const MEPP2GammaGamma &) |
The assignment operator is private and must never be called. | |
double | qqbarME (vector< SpinorWaveFunction > &fin, vector< SpinorBarWaveFunction > &ain, vector< VectorWaveFunction > &p1, vector< VectorWaveFunction > &p2, bool me) const |
Members to return the matrix elements for the different subprocesses. | |
double | ggME (vector< VectorWaveFunction > &g1, vector< VectorWaveFunction > &g2, vector< VectorWaveFunction > &p1, vector< VectorWaveFunction > &p2, bool me) const |
Matrix element for ![]() | |
Private Attributes | |
AbstractFFVVertexPtr | _photonvertex |
Pointer to the quark-antiquark-photon vertex. | |
unsigned int | _maxflavour |
Maximum PDG code of the quarks allowed. | |
unsigned int | _process |
Option for which processes to include. | |
ProductionMatrixElement | _me |
Matrix element for spin correlations. | |
double | _diagwgt [2] |
weights for the different quark annhilation diagrams | |
Static Private Attributes | |
static ClassDescription < MEPP2GammaGamma > | initMEPP2GammaGamma |
The static object used to initialize the description of this class. |
The MEPP2GammaGamma class implements the production of photon pairs in hadron hadron collisions.
Definition at line 34 of file MEPP2GammaGamma.h.
virtual IBPtr Herwig::MEPP2GammaGamma::clone | ( | ) | const [protected, virtual] |
Make a simple clone of this object.
Implements ThePEG::InterfacedBase.
virtual Selector<const ColourLines *> Herwig::MEPP2GammaGamma::colourGeometries | ( | tcDiagPtr | diag | ) | const [virtual] |
Return a Selector with possible colour geometries for the selected diagram weighted by their relative probabilities.
diag | the diagram chosen. |
Implements ThePEG::MEBase.
virtual Selector<DiagramIndex> Herwig::MEPP2GammaGamma::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.
dv | the diagrams to be weighted. |
Reimplemented from ThePEG::MEBase.
virtual void Herwig::MEPP2GammaGamma::doinit | ( | ) | [protected, virtual] |
Initialize this object after the setup phase before saving an EventGenerator to disk.
InitException | if object could not be initialized properly. |
Reimplemented from ThePEG::InterfacedBase.
virtual IBPtr Herwig::MEPP2GammaGamma::fullclone | ( | ) | const [protected, virtual] |
Make a clone of this object, possibly modifying the cloned object to make it sane.
Reimplemented from ThePEG::InterfacedBase.
double Herwig::MEPP2GammaGamma::ggME | ( | vector< VectorWaveFunction > & | g1, |
vector< VectorWaveFunction > & | g2, | ||
vector< VectorWaveFunction > & | p1, | ||
vector< VectorWaveFunction > & | p2, | ||
bool | me | ||
) | const [private] |
Matrix element for .
g1 | Polarization vectors for the first incoming gluon |
g2 | Polarization vectors for the second incoming gluon |
p1 | Polarization vectors for the first outgoing photon |
p2 | Polarization vectors for the second outgoing photon |
me | Whether or not to calculate the matrix element for spin correlations |
Complex Herwig::MEPP2GammaGamma::ggme | ( | Energy2 | s, |
Energy2 | t, | ||
Energy2 | u | ||
) | const [inline, private] |
matrix element for the
helicity configuration.
s | The ![]() |
t | The ![]() |
u | The ![]() |
Definition at line 197 of file MEPP2GammaGamma.h.
References abs(), ThePEG::Constants::pi, sqr(), and ZERO.
static void Herwig::MEPP2GammaGamma::Init | ( | ) | [static] |
The standard Init function used to initialize the interfaces.
Called exactly once for each class by the class description system before the main function starts or when this class is dynamically loaded.
Reimplemented from Herwig::HwMEBase.
virtual double Herwig::MEPP2GammaGamma::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.
Implements ThePEG::MEBase.
MEPP2GammaGamma& Herwig::MEPP2GammaGamma::operator= | ( | const MEPP2GammaGamma & | ) | [private] |
The assignment operator is private and must never be called.
In fact, it should not even be implemented.
void Herwig::MEPP2GammaGamma::persistentInput | ( | PersistentIStream & | is, |
int | version | ||
) |
Function used to read in object persistently.
is | the persistent input stream read from. |
version | the version number of the object when written. |
Reimplemented from Herwig::HwMEBase.
void Herwig::MEPP2GammaGamma::persistentOutput | ( | PersistentOStream & | os | ) | const |
Function used to write out object persistently.
os | the persistent output stream written to. |
Reimplemented from Herwig::HwMEBase.
double Herwig::MEPP2GammaGamma::qqbarME | ( | vector< SpinorWaveFunction > & | fin, |
vector< SpinorBarWaveFunction > & | ain, | ||
vector< VectorWaveFunction > & | p1, | ||
vector< VectorWaveFunction > & | p2, | ||
bool | me | ||
) | const [private] |
Members to return the matrix elements for the different subprocesses.
Matrix element for .
fin | Spinors for incoming quark |
ain | Spinors for incoming antiquark |
p1 | Polarization vectors for the first outgoing photon |
p2 | Polarization vectors for the second outgoing photon |
me | Whether or not to calculate the matrix element for spin correlations |
ClassDescription<MEPP2GammaGamma> Herwig::MEPP2GammaGamma::initMEPP2GammaGamma [static, private] |
The static object used to initialize the description of this class.
Indicates that this is a concrete class with persistent data.
Definition at line 214 of file MEPP2GammaGamma.h.