PhasespaceHelpers.h

// -*- C++ -*-
//
// PhasespaceHelpers.h is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef HERWIG_PhasespaceHelpers_H
#define HERWIG_PhasespaceHelpers_H
 
#include "ThePEG/Config/ThePEG.h"
#include "ThePEG/PDT/ParticleData.h"
 
#include "ThePEG/Persistency/PersistentOStream.h"
#include "ThePEG/Persistency/PersistentIStream.h"
 
#include "Herwig/MatrixElement/Matchbox/Phasespace/MatchboxPhasespace.h"
 
namespace Herwig {
 
using namespace ThePEG;
 
  namespace PhasespaceHelpers {
 
    struct PhasespaceInfo {
 
      Energy2 sHat;
 
      Energy sqrtSHat;
 
      double weight;
 
      StreamingRnd rnd;
 
      double x0;
 
      double xc;
 
      Energy M0;
 
      Energy Mc;
 
      Energy generateMass(tcPDPtr, const pair<Energy,Energy>&);
 
      Lorentz5Momentum generateKt(const Lorentz5Momentum& p1,
                                  const Lorentz5Momentum& p2,
                                  Energy pt);
 
    };
 
    struct PhasespaceTree {
 
      PhasespaceTree()
        : massRange(ZERO,ZERO), externalId(-1), 
          spacelike(false) {}
 
      tcPDPtr data;
 
      pair<Energy,Energy> massRange;
 
      Lorentz5Momentum momentum;
 
      Lorentz5Momentum backwardMomentum;
 
      int externalId;
 
      vector<PhasespaceTree> children;
 
      set<int> leafs;
 
      bool spacelike;
 
      bool doMirror;
      
      void setup(const Tree2toNDiagram&, int pos = 0);
 
      void setupMirrored(const Tree2toNDiagram& diag, int pos);
 
      void init(const vector<Lorentz5Momentum>&);
 
      void generateKinematics(PhasespaceInfo&,
                              vector<Lorentz5Momentum>&);
 
      void put(PersistentOStream&) const;
 
      void get(PersistentIStream&);
 
      void print(int in = 0);
 
    };
 
  }
 
}
 
#endif // HERWIG_PhasespaceHelpers_H