ThePEG/MatrixElement/MEQQ2QQ3.h

0001 // -*- C++ -*-
0002 //
0003 // MEQQ2QQ3.h is a part of ThePEG - Toolkit for HEP Event Generation
0004 // Copyright (C) 1999-2019 Leif Lonnblad
0005 //
0006 // ThePEG 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 ThePEG_MEQQ2QQ_H
0010 #define ThePEG_MEQQ2QQ_H
0011 // This is the declaration of the MEQQ2QQ class.
0012
0013 #include "ThePEG/MatrixElement/ME2to2QCD.h"
0014 // #include "MEQQ2QQ.fh"
0015 // #include "MEQQ2QQ.xh"
0016
0017 namespace ThePEG {
0018
0019 /**
0020  * MEQQ2QQ inherits from ME2to2QCD and implements the standard
0021  * \f$q_iq_i\rightarrow q_iq_i\f$ matrix element.
0022  *
0023  * @see \ref MEQQ2QQInterfaces "The interfaces"
0024  * defined for MEQQ2QQ.
0025  * @see ME2to2QCD
0026  */
0027 class MEQQ2QQ: public ME2to2QCD {
0028
0029 public:
0030
0031   /** @name Virtual functions required by the MEBase class. */
0032   //@{
0033   /**
0034    * The matrix element for the kinematical configuration
0035    * previously provided by the last call to setKinematics(), suitably
0036    * scaled by sHat() to give a dimension-less number.
0037    * @return the matrix element scaled with sHat() to give a
0038    * dimensionless number.
0039    */
0040   virtual double me2() const;
0041
0042   /**
0043    * Add all possible diagrams with the add() function.
0044    */
0045   virtual void getDiagrams() const;
0046
0047   /**
0048    * Return a Selector with possible colour geometries for the selected
0049    * diagram weighted by their relative probabilities.
0050    * @param diag the diagram chosen.
0051    * @return the possible colour geometries weighted by their
0052    * relative probabilities.
0053    */
0054   virtual Selector<const ColourLines *>
0055   colourGeometries(tcDiagPtr diag) const;
0056
0057   /**
0058    * Get diagram selector. With the information previously supplied with the
0059    * setKinematics method, a derived class may optionally
0060    * override this method to weight the given diagrams with their
0061    * (although certainly not physical) relative probabilities.
0062    * @param dv the diagrams to be weighted.
0063    * @return a Selector relating the given diagrams to their weights.
0064    */
0065   virtual Selector<DiagramIndex> diagrams(const DiagramVector & dv) const;
0066   //@}
0067
0068 protected:
0069
0070   /** @name Internal functions returning the matrix element squared
0071    *  for different colour configurations. */
0072   //@{
0073   /**
0074    * Return the matrix element squared (without common pre-factors)
0075    * for the specific colour configuration.
0076    */
0077   double colA() const
0078   {
0079     return (sqr(uHat()) + sqr(sHat()))/sqr(tHat());
0080   }
0081
0082
0083   /**
0084    * Return the matrix element squared (without common pre-factors)
0085    * for the specific colour configuration.
0086    */
0087   double colB() const
0088   {
0089     return (sqr(tHat()) + sqr(sHat()))/sqr(uHat());
0090   }
0091   //@}
0092
0093 public:
0094
0095   /**
0096    * Standard Init function used to initialize the interfaces.
0097    */
0098   static void Init();
0099
0100 protected:
0101
0102   /** @name Clone Methods. */
0103   //@{
0104   /**
0105    * Make a simple clone of this object.
0106    * @return a pointer to the new object.
0107    */
0108   virtual IBPtr clone() const;
0109
0110   /** Make a clone of this object, possibly modifying the cloned object
0111    * to make it sane.
0112    * @return a pointer to the new object.
0113    */
0114   virtual IBPtr fullclone() const;
0115   //@}
0116
0117 private:
0118
0119   /**
0120    * Describe a concrete class without persistent data.
0121    */
0122   static NoPIOClassDescription<MEQQ2QQ> initMEQQ2QQ;
0123
0124   /**
0125    *  Private and non-existent assignment operator.
0126    */
0127   MEQQ2QQ & operator=(const MEQQ2QQ &) = delete;
0128
0129 };
0130
0131 }
0132
0133
0134 namespace ThePEG {
0135
0136 /** @cond TRAITSPECIALIZATIONS */
0137
0138 /** This template specialization informs ThePEG about the
0139  *  base classes of MEQQ2QQ. */
0140 template <>
0141 struct BaseClassTrait<MEQQ2QQ,1>: public ClassTraitsType {
0142   /** Typedef of the first base class of MEQQ2QQ. */
0143   typedef ME2to2QCD NthBase;
0144 };
0145
0146 /** This template specialization informs ThePEG about the name of
0147  *  the MEQQ2QQ class and the shared object where it is defined. */
0148 template <>
0149 struct ClassTraits<MEQQ2QQ>: public ClassTraitsBase<MEQQ2QQ> {
0150   /** Return a platform-independent class name */
0151   static string className() { return "ThePEG::MEQQ2QQ"; }
0152   /** Return the name of the shared library be loaded to get
0153    *  access to the MEQQ2QQ class and every other class it uses
0154    *  (except the base class). */
0155   static string library() { return "MEQCD.so"; }
0156 };
0157
0158 /** @endcond */
0159
0160 }
0161
0162 #endif /* ThePEG_MEQQ2QQ_H */