Builtin/Amplitudes/MatchboxAmplitudehggg.h

0001 // -*- C++ -*-
0002 //
0003 // MatchboxAmplitudehggg.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_MatchboxAmplitudehggg_H
0010 #define Herwig_MatchboxAmplitudehggg_H
0011 //
0012 // This is the declaration of the MatchboxAmplitudehggg class.
0013 //
0014
0015 #include "Herwig/MatrixElement/Matchbox/Base/MatchboxAmplitude.h"
0016 #include "Herwig/MatrixElement/Matchbox/Builtin/Amplitudes/MatchboxCurrents.h"
0017
0018 namespace Herwig {
0019
0020 using namespace ThePEG;
0021
0022 /**
0023  * \ingroup Matchbox
0024  * \author Benedikt Zimmermann
0025  *
0026  * \brief MatchboxAmplitudehggg
0027  */
0028 class MatchboxAmplitudehggg:
0029     public MatchboxAmplitude, public MatchboxCurrents {
0030
0031 public:
0032
0033   /**
0034    * The default constructor.
0035    */
0036   MatchboxAmplitudehggg();
0037
0038 public:
0039
0040   /**
0041    * Return true, if this amplitude can handle the given process.
0042    */
0043   virtual bool canHandle(const PDVector&) const;
0044
0045   /**
0046    * Return the (tree-level) order in \f$g_S\f$ in which this matrix
0047    * element is given.
0048    */
0049   virtual unsigned int orderInGs() const { return 3; }
0050
0051   /**
0052    * Return the (tree-level) order in \f$g_{EM}\f$ in which this matrix
0053    * element is given.
0054    */
0055   virtual unsigned int orderInGem() const { return 1; }
0056
0057   /**
0058    * Return true, if this amplitude is capable of calculating one-loop
0059    * (QCD) corrections.
0060    */
0061   virtual bool haveOneLoop() const { return false; }
0062
0063   /**
0064    * Calculate the tree level amplitudes for the phasespace point
0065    * stored in lastXComb.
0066    */
0067   virtual void prepareAmplitudes(Ptr<MatchboxMEBase>::tcptr);
0068
0069   /**
0070    * Evaluate the amplitude for the given colour tensor id and
0071    * helicity assignment
0072    */
0073   virtual Complex evaluate(size_t, const vector<int>&, Complex&);
0074
0075   /**
0076    * Evaluate the amplitude for the given colour tensor id and
0077    * helicity assignment
0078    */
0079   //virtual Complex evaluateOneLoop(size_t, const vector<int>&);
0080
0081   /**
0082    * Return true, if one loop corrections are given in the conventions
0083    * of BDK.
0084    */
0085   virtual bool isBDK() const { return true; }
0086
0087   /**
0088    * Return the value of the dimensional regularization
0089    * parameter. Note that renormalization scale dependence is fully
0090    * restored in DipoleIOperator.
0091    */
0092   virtual Energy2 mu2() const { return lastSHat(); }
0093
0094   /**
0095    * Flush all cashes.
0096    */
0097   virtual void flushCaches() {
0098     MatchboxCurrents::reset();
0099     MatchboxAmplitude::flushCaches();
0100   }
0101
0102 public:
0103   /*
0104    * The interfaced THooftMass
0105    */
0106   Energy interfaceTHooft;
0107   /** @name Functions used by the persistent I/O system. */
0108   //@{
0109   /**
0110    * Function used to write out object persistently.
0111    * @param os the persistent output stream written to.
0112    */
0113   void persistentOutput(PersistentOStream & os) const;
0114
0115   /**
0116    * Function used to read in object persistently.
0117    * @param is the persistent input stream read from.
0118    * @param version the version number of the object when written.
0119    */
0120   void persistentInput(PersistentIStream & is, int version);
0121   //@}
0122
0123   /**
0124    * The standard Init function used to initialize the interfaces.
0125    * Called exactly once for each class by the class description system
0126    * before the main function starts or
0127    * when this class is dynamically loaded.
0128    */
0129   static void Init();
0130
0131 protected:
0132
0133   /** @name Clone Methods. */
0134   //@{
0135   /**
0136    * Make a simple clone of this object.
0137    * @return a pointer to the new object.
0138    */
0139   virtual IBPtr clone() const;
0140
0141   /** Make a clone of this object, possibly modifying the cloned object
0142    * to make it sane.
0143    * @return a pointer to the new object.
0144    */
0145   virtual IBPtr fullclone() const;
0146   //@}
0147
0148
0149 // If needed, insert declarations of virtual function defined in the
0150 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0151
0152 protected:
0153
0154   /** @name Standard Interfaced functions. */
0155   //@{
0156   /**
0157    * Initialize this object after the setup phase before saving an
0158    * EventGenerator to disk.
0159    * @throws InitException if object could not be initialized properly.
0160    */
0161   virtual void doinit();
0162
0163   /**
0164    * Initialize this object. Called in the run phase just before
0165    * a run begins.
0166    */
0167   virtual void doinitrun();
0168   //@}
0169
0170 private:
0171
0172   /**
0173    * The assignment operator is private and must never be called.
0174    * In fact, it should not even be implemented.
0175    */
0176   MatchboxAmplitudehggg & operator=(const MatchboxAmplitudehggg &) = delete;
0177
0178 };
0179
0180 }
0181
0182 #endif /* Herwig_MatchboxAmplitudehggg_H */
0183