EIC code displayed by LXR master/​include/​Herwig/​MatrixElement/​Hadron/​MEqq2gZ2ff.h	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2026-08-06 09:24:09

 // -*- C++ -*-
 //
 // MEqq2gZ2ff.h is a part of Herwig - A multi-purpose Monte Carlo event generator
 // Copyright (C) 2002-2019 The Herwig Collaboration
 //
 // Herwig is licenced under version 3 of the GPL, see COPYING for details.
 // Please respect the MCnet academic guidelines, see GUIDELINES for details.
 //
 #ifndef HERWIG_MEqq2gZ2ff_H
 #define HERWIG_MEqq2gZ2ff_H
 //
 // This is the declaration of the MEqq2gZ2ff class.
 //
 
 #include "Herwig/MatrixElement/DrellYanBase.h"
 #include "Herwig/MatrixElement/ProductionMatrixElement.h"
 #include "ThePEG/Helicity/WaveFunction/SpinorWaveFunction.h"
 #include "ThePEG/Helicity/WaveFunction/SpinorBarWaveFunction.h"
 #include "ThePEG/Helicity/Vertex/AbstractFFVVertex.fh"
 
 namespace Herwig {
 
 using namespace ThePEG;
 using namespace ThePEG::Helicity;
 
 /**
  * The MEqq2gZ2ff class implements the products of Standard Model
  * fermion antifermion pairs via the \f$Z^0\f$ resonance including
  * photon interference terms.
  *
  * @see \ref MEqq2gZ2ffInterfaces "The interfaces"
  * defined for MEqq2gZ2ff.
  */
 class MEqq2gZ2ff: public DrellYanBase {
 
 public:
 
   /**
    * The default constructor.
    */
   MEqq2gZ2ff();
 
   /** @name Virtual functions required by the MEBase class. */
   //@{
   /**
    * Return the order in \f$\alpha_S\f$ in which this matrix
    * element is given.
    */
   virtual unsigned int orderInAlphaS() const;
 
   /**
    * Return the order in \f$\alpha_{EW}\f$ in which this matrix
    * element is given.
    */
   virtual unsigned int orderInAlphaEW() 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.
    * @return the matrix element scaled with sHat() to give a
    * dimensionless number.
    */
   virtual double me2() const;
 
   /**
    * Return the scale associated with the last set phase space point.
    */
   virtual Energy2 scale() const;
 
   /**
    * Add all possible diagrams with the add() function.
    */
   virtual void getDiagrams() const;
 
   /**
    * 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.
    * @param dv the diagrams to be weighted.
    * @return a Selector relating the given diagrams to their weights.
    */
   virtual Selector<DiagramIndex> diagrams(const DiagramVector & dv) const;
 
   /**
    * Return a Selector with possible colour geometries for the selected
    * diagram weighted by their relative probabilities.
    * @param diag the diagram chosen.
    * @return the possible colour geometries weighted by their
    * relative probabilities.
    */
   virtual Selector<const ColourLines *>
   colourGeometries(tcDiagPtr diag) const;
 
   /**
    *  Construct the vertex of spin correlations.
    */
   virtual void constructVertex(tSubProPtr);
   //@}
 
 
 public:
 
   /** @name Functions used by the persistent I/O system. */
   //@{
   /**
    * Function used to write out object persistently.
    * @param os the persistent output stream written to.
    */
   void persistentOutput(PersistentOStream & os) const;
 
   /**
    * Function used to read in object persistently.
    * @param is the persistent input stream read from.
    * @param version the version number of the object when written.
    */
   void persistentInput(PersistentIStream & is, int version);
   //@}
 
   /**
    * 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.
    */
   static void Init();
 
 protected:
 
   /**
    * Matrix element for \f$q\bar{q}\to \gamma/Z \to f\bar{f}\f$.
    * @param fin  Spinors for incoming quark
    * @param ain  Spinors for incoming antiquark
    * @param fout Spinors for incoming quark
    * @param aout Spinors for incoming antiquark
    * @param me  Whether or not to calculate the matrix element for spin correlations
    */
   double qqbarME(vector<SpinorWaveFunction>    & fin ,
          vector<SpinorBarWaveFunction> & ain ,
          vector<SpinorBarWaveFunction> & fout,
          vector<SpinorWaveFunction>    & aout,
          bool me) const;
 
 protected:
 
   /** @name Clone Methods. */
   //@{
   /**
    * Make a simple clone of this object.
    * @return a pointer to the new object.
    */
   virtual IBPtr clone() const { return new_ptr(*this); }
 
   /** Make a clone of this object, possibly modifying the cloned object
    * to make it sane.
    * @return a pointer to the new object.
    */
   virtual IBPtr fullclone() const { return new_ptr(*this); }
   //@}
 
 protected:
 
   /** @name Standard Interfaced functions. */
   //@{
   /**
    * Initialize this object after the setup phase before saving an
    * EventGenerator to disk.
    * @throws InitException if object could not be initialized properly.
    */
   virtual void doinit();
   //@}
 
 private:
 
   /**
    * The assignment operator is private and must never be called.
    * In fact, it should not even be implemented.
    */
   MEqq2gZ2ff & operator=(const MEqq2gZ2ff &) = delete;
 
 private:
 
   /**
    *  Pointer to the vertices for the helicity calculations
    */
   //@{
   /**
    *  Pointer to the Z vertex
    */
   AbstractFFVVertexPtr _theFFZVertex;
 
   /**
    *  Pointer to the photon vertex
    */
   AbstractFFVVertexPtr _theFFPVertex;
   //@}
 
   /**
    *  Pointers to the intermediate resonances
    */
   //@{
   /**
    *  Pointer to the Z ParticleData object
    */
   tcPDPtr _z0;
 
   /**
    *  Pointer to the photon ParticleData object
    */
   tcPDPtr _gamma;
   //@}
 
   /**
    *  Switches to control the particles in the hard process
    */
   //@{
   /**
    *  Minimum allowed flavour for the incoming quarks
    */
   int _minflavour;
 
   /**
    *  Maximum allowed flavour for the incoming quarks
    */
   int _maxflavour;
 
   /**
    *  Whether to include both \f$Z^0\f$ and \f$\gamma\f$ or only one
    */
   unsigned int _gammaZ;
   
   /**
    *  Which processes to include
    */
   int _process;
   //@}
 
   /**
    * Matrix element for spin correlations
    */
   ProductionMatrixElement _me;
 
   /**
    *  Whether of not to construct the vertex for spin correlations
    */
   bool spinCorrelations_;
 };
 
 }
 
 #endif /* HERWIG_MEqq2gZ2ff_H */

This page was automatically generated by the 2.3.7 LXR engine. The LXR team