Matchbox/Phasespace/FIMassiveTildeKinematics.h

0001 // -*- C++ -*-
0002 //
0003 // FIMassiveTildeKinematics.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_FIMassiveTildeKinematics_H
0010 #define HERWIG_FIMassiveTildeKinematics_H
0011 //
0012 // This is the declaration of the FIMassiveTildeKinematics 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, Martin Stoll
0024  *
0025  * \brief FIMassiveTildeKinematics implements the 'tilde' kinematics for
0026  * a final-initial subtraction dipole.
0027  *
0028  */
0029 class FIMassiveTildeKinematics: 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    * Return the pt associated to emitter emission and sppectator momentum.
0050    */
0051   virtual Energy lastPt(Lorentz5Momentum,Lorentz5Momentum,Lorentz5Momentum) const ;
0052
0053   /**
0054    * Given a pt, return the boundaries on z
0055    */
0056   virtual pair<double,double> zBounds(Energy pt, Energy hardPt ) const;
0057
0058   /**
0059    * Return the momentum fraction associated to the last splitting.
0060    */
0061   virtual double lastZ() const;
0062
0063 public:
0064   /**
0065    * Triangular / Kallen function
0066    */
0067   template <class T>
0068   inline T rootOfKallen (T a, T b, T c) const {
0069     return sqrt( a*a + b*b + c*c - 2.*( a*b+a*c+b*c ) ); }
0070
0071   /** @name Functions used by the persistent I/O system. */
0072   //@{
0073   /**
0074    * Function used to write out object persistently.
0075    * @param os the persistent output stream written to.
0076    */
0077   void persistentOutput(PersistentOStream & os) const;
0078
0079   /**
0080    * Function used to read in object persistently.
0081    * @param is the persistent input stream read from.
0082    * @param version the version number of the object when written.
0083    */
0084   void persistentInput(PersistentIStream & is, int version);
0085   //@}
0086
0087   /**
0088    * The standard Init function used to initialize the interfaces.
0089    * Called exactly once for each class by the class description system
0090    * before the main function starts or
0091    * when this class is dynamically loaded.
0092    */
0093   static void Init();
0094
0095 protected:
0096
0097   /** @name Clone Methods. */
0098   //@{
0099   /**
0100    * Make a simple clone of this object.
0101    * @return a pointer to the new object.
0102    */
0103   virtual IBPtr clone() const;
0104
0105   /** Make a clone of this object, possibly modifying the cloned object
0106    * to make it sane.
0107    * @return a pointer to the new object.
0108    */
0109   virtual IBPtr fullclone() const;
0110   //@}
0111
0112
0113 // If needed, insert declarations of virtual function defined in the
0114 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0115
0116
0117 private:
0118
0119   /**
0120    * The assignment operator is private and must never be called.
0121    * In fact, it should not even be implemented.
0122    */
0123   FIMassiveTildeKinematics & operator=(const FIMassiveTildeKinematics &) = delete;
0124
0125 };
0126
0127 }
0128
0129 #endif /* HERWIG_FIMassiveTildeKinematics_H */