Matchbox/Phasespace/FFMassiveTildeKinematics.h

0001 // -*- C++ -*-
0002 //
0003 // FFMassiveTildeKinematics.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_FFMassiveTildeKinematics_H
0010 #define HERWIG_FFMassiveTildeKinematics_H
0011 //
0012 // This is the declaration of the FFMassiveTildeKinematics class.
0013 //
0014
0015 #include "Herwig/MatrixElement/Matchbox/Phasespace/TildeKinematics.h"
0016
0017 namespace Herwig {
0018
0019 using namespace ThePEG;
0020
0021 /**
0022  * \ingroup Matchbox
0023  * \author Simon Platzer, Stephen Webster
0024  *
0025  * \brief FFMassiveTildeKinematics implements the 'tilde' kinematics for
0026  * a final-final subtraction dipole.
0027  *
0028  */
0029 class FFMassiveTildeKinematics: public TildeKinematics {
0030
0031 public:
0032
0033   /**
0034    * Perform the mapping to the tilde kinematics for the
0035    * last selected process and store all dimensionless
0036    * variables in the subtractionParameters() vector.
0037    * Return false, if the calculation of the tilde
0038    * kinematics was impossible for the selected configuration
0039    * and true on success.
0040    */
0041   virtual bool doMap();
0042
0043   /**
0044    * Return the pt associated to the last merged splitting.
0045    */
0046   virtual Energy lastPt() const;
0047
0048   /**
0049    * Given a pt, return the boundaries on z
0050    */
0051   virtual pair<double,double> zBounds(Energy pt, Energy hardPt ) const;
0052
0053   /**
0054    * Return the pt associated to emitter emission and sppectator momentum.
0055    */
0056   virtual Energy lastPt(Lorentz5Momentum,Lorentz5Momentum,Lorentz5Momentum) const ;
0057
0058
0059   /**
0060    * Return the momentum fraction associated to the last splitting.
0061    */
0062   virtual double lastZ() const;
0063
0064 public:
0065
0066   /**
0067    * Triangular / Kallen function
0068    */
0069   template <class T>
0070   inline T rootOfKallen (T a, T b, T c) const {
0071     return sqrt( a*a + b*b + c*c - 2.*( a*b+a*c+b*c ) ); }
0072
0073 public:
0074
0075   /** @name Functions used by the persistent I/O system. */
0076   //@{
0077   /**
0078    * Function used to write out object persistently.
0079    * @param os the persistent output stream written to.
0080    */
0081   void persistentOutput(PersistentOStream & os) const;
0082
0083   /**
0084    * Function used to read in object persistently.
0085    * @param is the persistent input stream read from.
0086    * @param version the version number of the object when written.
0087    */
0088   void persistentInput(PersistentIStream & is, int version);
0089   //@}
0090
0091   /**
0092    * The standard Init function used to initialize the interfaces.
0093    * Called exactly once for each class by the class description system
0094    * before the main function starts or
0095    * when this class is dynamically loaded.
0096    */
0097   static void Init();
0098
0099 protected:
0100
0101   /** @name Clone Methods. */
0102   //@{
0103   /**
0104    * Make a simple clone of this object.
0105    * @return a pointer to the new object.
0106    */
0107   virtual IBPtr clone() const;
0108
0109   /** Make a clone of this object, possibly modifying the cloned object
0110    * to make it sane.
0111    * @return a pointer to the new object.
0112    */
0113   virtual IBPtr fullclone() const;
0114   //@}
0115
0116
0117 // If needed, insert declarations of virtual function defined in the
0118 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0119
0120
0121 private:
0122
0123   /**
0124    * The assignment operator is private and must never be called.
0125    * In fact, it should not even be implemented.
0126    */
0127   FFMassiveTildeKinematics & operator=(const FFMassiveTildeKinematics &) = delete;
0128
0129 };
0130
0131 }
0132
0133 #endif /* HERWIG_FFMassiveTildeKinematics_H */