Builtin/Amplitudes/MatchboxAmplitudehqqbarg.h

0001 // -*- C++ -*-
0002 //
0003 // MatchboxAmplitudehqqbarg.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_MatchboxAmplitudehqqbarg_H
0010 #define Herwig_MatchboxAmplitudehqqbarg_H
0011 //
0012 // This is the declaration of the MatchboxAmplitudehqqbarg 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 MatchboxAmplitudehqqbarg
0027  */
0028 class MatchboxAmplitudehqqbarg:
0029     public MatchboxAmplitude, public MatchboxCurrents {
0030
0031 public:
0032
0033   /**
0034    * The default constructor.
0035    */
0036   MatchboxAmplitudehqqbarg();
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    * Flush all cashes.
0095    */
0096   virtual void flushCaches() {
0097     MatchboxCurrents::reset();
0098     MatchboxAmplitude::flushCaches();
0099   }
0100
0101 public:
0102
0103   /** @name Functions used by the persistent I/O system. */
0104   //@{
0105   /**
0106    * Function used to write out object persistently.
0107    * @param os the persistent output stream written to.
0108    */
0109   void persistentOutput(PersistentOStream & os) const;
0110
0111   /**
0112    * Function used to read in object persistently.
0113    * @param is the persistent input stream read from.
0114    * @param version the version number of the object when written.
0115    */
0116   void persistentInput(PersistentIStream & is, int version);
0117   //@}
0118
0119   /**
0120    * The standard Init function used to initialize the interfaces.
0121    * Called exactly once for each class by the class description system
0122    * before the main function starts or
0123    * when this class is dynamically loaded.
0124    */
0125   static void Init();
0126
0127 protected:
0128
0129   /** @name Clone Methods. */
0130   //@{
0131   /**
0132    * Make a simple clone of this object.
0133    * @return a pointer to the new object.
0134    */
0135   virtual IBPtr clone() const;
0136
0137   /** Make a clone of this object, possibly modifying the cloned object
0138    * to make it sane.
0139    * @return a pointer to the new object.
0140    */
0141   virtual IBPtr fullclone() const;
0142   //@}
0143
0144
0145 // If needed, insert declarations of virtual function defined in the
0146 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0147
0148 protected:
0149
0150   /** @name Standard Interfaced functions. */
0151   //@{
0152   /**
0153    * Initialize this object after the setup phase before saving an
0154    * EventGenerator to disk.
0155    * @throws InitException if object could not be initialized properly.
0156    */
0157   virtual void doinit();
0158
0159   /**
0160    * Initialize this object. Called in the run phase just before
0161    * a run begins.
0162    */
0163   virtual void doinitrun();
0164   //@}
0165
0166 private:
0167   /*
0168    * The interfaced THooftMass
0169    */
0170   Energy interfaceTHooft;
0171   /**
0172    * The assignment operator is private and must never be called.
0173    * In fact, it should not even be implemented.
0174    */
0175   MatchboxAmplitudehqqbarg & operator=(const MatchboxAmplitudehqqbarg &) = delete;
0176
0177 };
0178
0179 }
0180
0181 #endif /* Herwig_MatchboxAmplitudehqqbarg_H */