Builtin/Amplitudes/MatchboxAmplitudelnuqqbarg.h

0001 // -*- C++ -*-
0002 //
0003 // MatchboxAmplitudelnuqqbarg.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_MatchboxAmplitudelnuqqbarg_H
0010 #define Herwig_MatchboxAmplitudelnuqqbarg_H
0011 //
0012 // This is the declaration of the MatchboxAmplitudelnuqqbarg class.
0013 //
0014
0015 #include "Herwig/MatrixElement/Matchbox/Base/MatchboxAmplitude.h"
0016 #include "Herwig/MatrixElement/Matchbox/Builtin/Amplitudes/MatchboxCurrents.h"
0017 #include "ThePEG/StandardModel/StandardModelBase.h"
0018 #include "ThePEG/Interface/ClassDocumentation.h"
0019 #include "ThePEG/EventRecord/Particle.h"
0020 #include "ThePEG/Repository/UseRandom.h"
0021 #include "ThePEG/Repository/EventGenerator.h"
0022 #include "ThePEG/Utilities/DescribeClass.h"
0023 #include "ThePEG/Persistency/PersistentOStream.h"
0024 #include "ThePEG/Persistency/PersistentIStream.h"
0025 #include "ThePEG/PDT/EnumParticles.h"
0026 #include "Herwig/MatrixElement/Matchbox/Utility/SU2Helper.h"
0027
0028 namespace Herwig {
0029
0030 using namespace ThePEG;
0031
0032 /**
0033  * \ingroup Matchbox
0034  * \author Thomas Schuh
0035  *
0036  * \brief MatchboxAmplitudelnuqqbarg
0037  */
0038 class MatchboxAmplitudelnuqqbarg: public MatchboxAmplitude, public MatchboxCurrents {
0039
0040 public:
0041
0042   /**
0043    * The default constructor.
0044    */
0045   MatchboxAmplitudelnuqqbarg();
0046
0047   /**
0048    * Return the (tree-level) order in \f$g_S\f$ in which this matrix
0049    * element is given.
0050    */
0051   virtual unsigned int orderInGs() const { return 1; }
0052
0053   /**
0054    * Return the (tree-level) order in \f$g_{EM}\f$ in which this matrix
0055    * element is given.
0056    */
0057   virtual unsigned int orderInGem() const { return 2; }
0058
0059   /**
0060    * Return true, if this amplitude is capable of calculating one-loop
0061    * (QCD) corrections.
0062    */
0063   virtual bool haveOneLoop() const { return true; }
0064
0065   /**
0066    * Return true, if this amplitude can handle the given process.
0067    */
0068   virtual bool canHandle(const PDVector&) const;
0069
0070   /**
0071    * Calculate the tree level amplitudes for the phasespace point
0072    * stored in lastXComb.
0073    */
0074   virtual void prepareAmplitudes(Ptr<MatchboxMEBase>::tcptr);
0075
0076   /**
0077    * Evaluate the amplitude for the given colour tensor id and
0078    * helicity assignment
0079    */
0080   virtual Complex evaluate(size_t, const vector<int>&, Complex&);
0081
0082   /**
0083    * Evaluate the amplitude for the given colour tensor id and
0084    * helicity assignment
0085    */
0086   virtual Complex evaluateOneLoop(size_t, const vector<int>&);
0087
0088   /**
0089    * Return true, if one loop corrections are given in the conventions
0090    * of BDK.
0091    */
0092   virtual bool isBDK() const { return true; }
0093
0094   /**
0095    * Return the value of the dimensional regularization
0096    * parameter. Note that renormalization scale dependence is fully
0097    * restored in DipoleIOperator.
0098    */
0099   virtual Energy2 mu2() const { return lastSHat(); }
0100
0101   /**
0102    * Flush all cashes.
0103    */
0104   virtual void flushCaches() {
0105     MatchboxCurrents::reset();
0106     MatchboxAmplitude::flushCaches();
0107   }
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    * The standard Init function used to initialize the interfaces.
0124    * Called exactly once for each class by the class description system
0125    * before the main function starts or
0126    * when this class is dynamically loaded.
0127    */
0128   static void Init();
0129
0130 protected:
0131
0132   /**
0133    * Make a simple clone of this object.
0134    * @return a pointer to the new object.
0135    */
0136   virtual IBPtr clone() const;
0137
0138   /** Make a clone of this object, possibly modifying the cloned object
0139    * to make it sane.
0140    * @return a pointer to the new object.
0141    */
0142   virtual IBPtr fullclone() const;
0143
0144   /**
0145    * Initialize this object after the setup phase before saving an
0146    * EventGenerator to disk.
0147    * @throws InitException if object could not be initialized properly.
0148    */
0149   virtual void doinit();
0150
0151   /**
0152    * Initialize this object. Called in the run phase just before
0153    * a run begins.
0154    */
0155   virtual void doinitrun();
0156
0157 private:
0158
0159   /**
0160    * True, if a diagonal CKM matrix should be assumed. This ignores
0161    * the CKM object of the StandardModel.
0162    */
0163   bool theDiagonal;
0164
0165   /**
0166    * The ckm.
0167    */
0168   vector< vector<Complex> > theCKM;
0169
0170   /**
0171    * The assignment operator is private and must never be called.
0172    * In fact, it should not even be implemented.
0173    */
0174   MatchboxAmplitudelnuqqbarg & operator=(const MatchboxAmplitudelnuqqbarg &) = delete;
0175
0176 };
0177
0178 }
0179
0180 #endif /* Herwig_MatchboxAmplitudelnuqqbarg_H */