Matchbox/Phasespace/IILightTildeKinematics.h

0001 // -*- C++ -*-
0002 //
0003 // IILightTildeKinematics.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_IILightTildeKinematics_H
0010 #define HERWIG_IILightTildeKinematics_H
0011 //
0012 // This is the declaration of the IILightTildeKinematics 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
0024  *
0025  * \breif IILightTildeKinematics implements the 'tilde' kinematics for
0026  * a initial-initial subtraction dipole.
0027  *
0028  */
0029 class IILightTildeKinematics: 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     //TODO: make this static?
0052   virtual Energy lastPt(Lorentz5Momentum,Lorentz5Momentum,Lorentz5Momentum) const ;
0053
0054   /**
0055    * Given a pt, return the boundaries on z
0056    */
0057   virtual pair<double,double> zBounds(Energy pt, Energy hardPt ) const;
0058
0059   /**
0060    * Return the momentum fraction associated to the last splitting.
0061    */
0062   virtual double lastZ() const;
0063
0064   /**
0065    * Return true, if this TildeKinematics object needs to transform
0066    * all other particles in the process except the emitter and spectator
0067    */
0068   virtual bool doesTransform() const { return true; }
0069
0070   /**
0071    * If this TildeKinematics object needs to transform all other particles
0072    * in the process except the emitter and spectator, return the transformed
0073    * momentum.
0074    */
0075   virtual Lorentz5Momentum transform(const Lorentz5Momentum& p) const;
0076
0077
0078   /*
0079    * True if phase space point is above the alpha cut for this dipole.
0080    */
0081
0082   bool aboveAlpha() const {return dipole()->alpha()<subtractionParameters()[1];}
0083
0084
0085 public:
0086
0087   /** @name Functions used by the persistent I/O system. */
0088   //@{
0089   /**
0090    * Function used to write out object persistently.
0091    * @param os the persistent output stream written to.
0092    */
0093   void persistentOutput(PersistentOStream & os) const;
0094
0095   /**
0096    * Function used to read in object persistently.
0097    * @param is the persistent input stream read from.
0098    * @param version the version number of the object when written.
0099    */
0100   void persistentInput(PersistentIStream & is, int version);
0101   //@}
0102
0103   /**
0104    * The standard Init function used to initialize the interfaces.
0105    * Called exactly once for each class by the class description system
0106    * before the main function starts or
0107    * when this class is dynamically loaded.
0108    */
0109   static void Init();
0110
0111 protected:
0112
0113   /** @name Clone Methods. */
0114   //@{
0115   /**
0116    * Make a simple clone of this object.
0117    * @return a pointer to the new object.
0118    */
0119   virtual IBPtr clone() const;
0120
0121   /** Make a clone of this object, possibly modifying the cloned object
0122    * to make it sane.
0123    * @return a pointer to the new object.
0124    */
0125   virtual IBPtr fullclone() const;
0126   //@}
0127
0128
0129 // If needed, insert declarations of virtual function defined in the
0130 // InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).
0131
0132 private:
0133
0134   /**
0135    * The K momentum used to transform the final state.
0136    */
0137   Lorentz5Momentum K;
0138
0139   /**
0140    * The Ktilde momentum used to transform the final state.
0141    */
0142   Lorentz5Momentum Ktilde;
0143
0144 private:
0145
0146   /**
0147    * The assignment operator is private and must never be called.
0148    * In fact, it should not even be implemented.
0149    */
0150   IILightTildeKinematics & operator=(const IILightTildeKinematics &) = delete;
0151
0152 };
0153
0154 }
0155
0156 #endif /* HERWIG_IILightTildeKinematics_H */