Builtin/Amplitudes/MatchboxAmplitudellbarqqbarqqbar.h

0001 // -*- C++ -*-
0002 //
0003 // MatchboxAmplitudellbarqqbarqqbar.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_MatchboxAmplitudellbarqqbarqqbar_H
0010 #define Herwig_MatchboxAmplitudellbarqqbarqqbar_H
0011 //
0012 // This is the declaration of the MatchboxAmplitudellbarqqbarqqbar class.
0013 //
0014
0015 #include "Herwig/MatrixElement/Matchbox/Builtin/Amplitudes/MatchboxZGammaAmplitude.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 Simon Platzer
0025  *
0026  * \brief MatchboxAmplitudellbarqqbarqqbar
0027  */
0028 class MatchboxAmplitudellbarqqbarqqbar:
0029     public MatchboxZGammaAmplitude, public MatchboxCurrents {
0030
0031 public:
0032
0033   /**
0034    * The default constructor.
0035    */
0036   MatchboxAmplitudellbarqqbarqqbar();
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 2; }
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 2; }
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    * Flush all cashes.
0077    */
0078   virtual void flushCaches() {
0079     MatchboxCurrents::reset();
0080     MatchboxZGammaAmplitude::flushCaches();
0081   }
0082
0083 public:
0084
0085   /** @name Functions used by the persistent I/O system. */
0086   //@{
0087   /**
0088    * Function used to write out object persistently.
0089    * @param os the persistent output stream written to.
0090    */
0091   void persistentOutput(PersistentOStream & os) const;
0092
0093   /**
0094    * Function used to read in object persistently.
0095    * @param is the persistent input stream read from.
0096    * @param version the version number of the object when written.
0097    */
0098   void persistentInput(PersistentIStream & is, int version);
0099   //@}
0100
0101   /**
0102    * The standard Init function used to initialize the interfaces.
0103    * Called exactly once for each class by the class description system
0104    * before the main function starts or
0105    * when this class is dynamically loaded.
0106    */
0107   static void Init();
0108
0109 protected:
0110
0111   /** @name Clone Methods. */
0112   //@{
0113   /**
0114    * Make a simple clone of this object.
0115    * @return a pointer to the new object.
0116    */
0117   virtual IBPtr clone() const;
0118
0119   /** Make a clone of this object, possibly modifying the cloned object
0120    * to make it sane.
0121    * @return a pointer to the new object.
0122    */
0123   virtual IBPtr fullclone() const;
0124   //@}
0125
0126
0127 // If needed, insert declarations of virtual function defined in the
0128 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0129
0130 protected:
0131
0132   /** @name Standard Interfaced functions. */
0133   //@{
0134   /**
0135    * Initialize this object after the setup phase before saving an
0136    * EventGenerator to disk.
0137    * @throws InitException if object could not be initialized properly.
0138    */
0139   virtual void doinit();
0140
0141   /**
0142    * Initialize this object. Called in the run phase just before
0143    * a run begins.
0144    */
0145   virtual void doinitrun();
0146   //@}
0147
0148 private:
0149
0150   /**
0151    * The assignment operator is private and must never be called.
0152    * In fact, it should not even be implemented.
0153    */
0154   MatchboxAmplitudellbarqqbarqqbar & operator=(const MatchboxAmplitudellbarqqbarqqbar &) = delete;
0155
0156 };
0157
0158 }
0159
0160 #endif /* Herwig_MatchboxAmplitudellbarqqbarqqbar_H */