Matchbox/Phasespace/IILightInvertedTildeKinematics.h

0001 // -*- C++ -*-
0002 //
0003 // IILightInvertedTildeKinematics.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_IILightInvertedTildeKinematics_H
0010 #define HERWIG_IILightInvertedTildeKinematics_H
0011 //
0012 // This is the declaration of the IILightInvertedTildeKinematics class.
0013 //
0014
0015 #include "Herwig/MatrixElement/Matchbox/Phasespace/InvertedTildeKinematics.h"
0016
0017 namespace Herwig {
0018
0019 using namespace ThePEG;
0020
0021 /**
0022  * \ingroup Matchbox
0023  * \author Simon Platzer
0024  *
0025  * \brief IILightInvertedTildeKinematics inverts the final-final tilde
0026  * kinematics.
0027  *
0028  */
0029 class IILightInvertedTildeKinematics: public Herwig::InvertedTildeKinematics {
0030
0031 public:
0032
0033   /**
0034    * Perform the mapping of 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 real
0038    * kinematics was impossible for the selected configuration
0039    * and true on success.
0040    */
0041   virtual bool doMap(const double *);
0042
0043   /**
0044    * Return the pt associated to the last generated splitting.
0045    */
0046   virtual Energy lastPt() const;
0047
0048   /**
0049    * Return the momentum fraction associated to the last splitting.
0050    */
0051   virtual double lastZ() const;
0052
0053   /**
0054    * Return the upper bound on pt
0055    */
0056   virtual Energy ptMax() const;
0057
0058   /**
0059    * Given a pt, return the boundaries on z
0060    */
0061   virtual pair<double,double> zBounds(Energy pt, Energy hardPt = ZERO) const;
0062
0063   /**
0064    * Return true, if this InvertedTildeKinematics object needs to transform
0065    * all other particles in the process except the emitter, emission and spectator
0066    */
0067   virtual bool doesTransform() const { return true; }
0068
0069   /**
0070    * If this InvertedTildeKinematics object needs to transform all other particles
0071    * in the process except the emitter, emission and spectator, return the transformed
0072    * momentum.
0073    */
0074   virtual Lorentz5Momentum transform(const Lorentz5Momentum& p) const {
0075     return p-(2.*(KplusKtilde*p)/KplusKtilde2)*KplusKtilde+(2.*(Ktilde*p)/K2)*K;
0076   }
0077
0078 public:
0079
0080   /** @name Functions used by the persistent I/O system. */
0081   //@{
0082   /**
0083    * Function used to write out object persistently.
0084    * @param os the persistent output stream written to.
0085    */
0086   void persistentOutput(PersistentOStream & os) const;
0087
0088   /**
0089    * Function used to read in object persistently.
0090    * @param is the persistent input stream read from.
0091    * @param version the version number of the object when written.
0092    */
0093   void persistentInput(PersistentIStream & is, int version);
0094   //@}
0095
0096   /**
0097    * The standard Init function used to initialize the interfaces.
0098    * Called exactly once for each class by the class description system
0099    * before the main function starts or
0100    * when this class is dynamically loaded.
0101    */
0102   static void Init();
0103
0104 protected:
0105
0106   /** @name Clone Methods. */
0107   //@{
0108   /**
0109    * Make a simple clone of this object.
0110    * @return a pointer to the new object.
0111    */
0112   virtual IBPtr clone() const;
0113
0114   /** Make a clone of this object, possibly modifying the cloned object
0115    * to make it sane.
0116    * @return a pointer to the new object.
0117    */
0118   virtual IBPtr fullclone() const;
0119   //@}
0120
0121
0122 // If needed, insert declarations of virtual function defined in the
0123 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0124
0125 private:
0126
0127   Lorentz5Momentum K;
0128   Energy2 K2;
0129   Lorentz5Momentum Ktilde;
0130   Lorentz5Momentum KplusKtilde;
0131   Energy2 KplusKtilde2;
0132
0133 private:
0134
0135   /**
0136    * The assignment operator is private and must never be called.
0137    * In fact, it should not even be implemented.
0138    */
0139   IILightInvertedTildeKinematics & operator=(const IILightInvertedTildeKinematics &) = delete;
0140
0141 };
0142
0143 }
0144
0145 #endif /* HERWIG_IILightInvertedTildeKinematics_H */