Matchbox/Dipoles/IIggxDipole.h

0001 // -*- C++ -*-
0002 //
0003 // IIggxDipole.h is a part of Herwig - A multi-purpose Monte Carlo event generator
0004 // Copyright (C) 2002-2019 The Herwig Collaboration
0005 //
0006 // Herwig is licenced under version 3 of the GPL, see COPYING for details.
0007 // Please respect the MCnet academic guidelines, see GUIDELINES for details.
0008 //
0009 #ifndef HERWIG_IIggxDipole_H
0010 #define HERWIG_IIggxDipole_H
0011 //
0012 // This is the declaration of the IIggxDipole class.
0013 //
0014
0015 #include "Herwig/MatrixElement/Matchbox/Dipoles/SubtractionDipole.h"
0016
0017 namespace Herwig {
0018
0019 using namespace ThePEG;
0020
0021 /**
0022  * \ingroup Matchbox
0023  * \author Simon Platzer
0024  *
0025  * \brief IIggxDipole implements the D^{g,g;b} subtraction dipole.
0026  *
0027  */
0028 class IIggxDipole: public SubtractionDipole {
0029
0030 public:
0031
0032   /**
0033    * The default constructor.
0034    */
0035   IIggxDipole();
0036
0037 public:
0038
0039   /**
0040    * Return true, if this dipole can possibly handle the indicated
0041    * emitter.
0042    */
0043   virtual bool canHandleEmitter(const cPDVector& partons, int emitter) const {
0044     return emitter < 2 && partons[emitter]->id() == ParticleID::g;
0045   }
0046
0047   /**
0048    * Return true, if this dipole can possibly handle the indicated
0049    * splitting.
0050    */
0051   virtual bool canHandleSplitting(const cPDVector& partons, int emitter, int emission) const {
0052     return canHandleEmitter(partons,emitter) && partons[emission]->id() == ParticleID::g;
0053   }
0054
0055   /**
0056    * Return true, if this dipole can possibly handle the indicated
0057    * spectator.
0058    */
0059   virtual bool canHandleSpectator(const cPDVector& partons, int spectator) const {
0060     return spectator < 2 && partons[spectator]->coloured();
0061   }
0062
0063   /**
0064    * Return true, if this dipole applies to the selected
0065    * configuration.
0066    */
0067   virtual bool canHandle(const cPDVector& partons,
0068              int emitter, int emission, int spectator) const;
0069   /**
0070    *  How to sample the z-distribution.
0071    *  FlatZ = 1
0072    *  OneOverZ = 2
0073    *  OneOverOneMinusZ = 3
0074    *  OneOverZOneMinusZ = 4
0075    */
0076
0077   virtual int samplingZ() const {return 4;}
0078
0079   /**
0080    * Return the matrix element for the kinematical configuation
0081    * previously provided by the last call to setKinematics(), suitably
0082    * scaled by sHat() to give a dimension-less number.
0083    */
0084   virtual double me2() const;
0085
0086   /**
0087    * Return the matrix element averaged over spin correlations.
0088    */
0089   virtual double me2Avg(double ccme2) const;
0090
0091 public:
0092
0093   /** @name Functions used by the persistent I/O system. */
0094   //@{
0095   /**
0096    * Function used to write out object persistently.
0097    * @param os the persistent output stream written to.
0098    */
0099   void persistentOutput(PersistentOStream & os) const;
0100
0101   /**
0102    * Function used to read in object persistently.
0103    * @param is the persistent input stream read from.
0104    * @param version the version number of the object when written.
0105    */
0106   void persistentInput(PersistentIStream & is, int version);
0107   //@}
0108
0109   /**
0110    * The standard Init function used to initialize the interfaces.
0111    * Called exactly once for each class by the class description system
0112    * before the main function starts or
0113    * when this class is dynamically loaded.
0114    */
0115   static void Init();
0116
0117 protected:
0118
0119   /** @name Clone Methods. */
0120   //@{
0121   /**
0122    * Make a simple clone of this object.
0123    * @return a pointer to the new object.
0124    */
0125   virtual IBPtr clone() const;
0126
0127   /** Make a clone of this object, possibly modifying the cloned object
0128    * to make it sane.
0129    * @return a pointer to the new object.
0130    */
0131   virtual IBPtr fullclone() const;
0132   //@}
0133
0134
0135 // If needed, insert declarations of virtual function defined in the
0136 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0137
0138
0139 private:
0140
0141   /**
0142    * The assignment operator is private and must never be called.
0143    * In fact, it should not even be implemented.
0144    */
0145   IIggxDipole & operator=(const IIggxDipole &) = delete;
0146
0147 };
0148
0149 }
0150
0151 #endif /* HERWIG_IIggxDipole_H */