EtaPiGammaGammaDecayer.h

// -*- C++ -*-
//
// EtaPiGammaGammaDecayer.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_EtaPiGammaGammaDecayer_H
#define HERWIG_EtaPiGammaGammaDecayer_H
// This is the declaration of the EtaPiGammaGammaDecayer class.
 
#include "Herwig/Decay/DecayIntegrator.h"
#include "Herwig/Decay/PhaseSpaceMode.h"
#include "ThePEG/StandardModel/StandardModelBase.h"
#include "Herwig/Utilities/Kinematics.h"
#include "ThePEG/Helicity/LorentzPolarizationVector.h"
 
namespace Herwig {
using namespace ThePEG;
 
class EtaPiGammaGammaDecayer: public DecayIntegrator {
 
public:
 
  EtaPiGammaGammaDecayer();
  
  virtual int modeNumber(bool & cc, tcPDPtr parent, 
                         const tPDVector & children) const;
  
  double me2(const int ichan,const Particle & part,
             const tPDVector & outgoing,
             const vector<Lorentz5Momentum> & momenta,
             MEOption meopt) const;
 
  virtual void constructSpinInfo(const Particle & part,
                                 ParticleVector outgoing) const;
 
  virtual WidthCalculatorBasePtr threeBodyMEIntegrator(const DecayMode & dm) const;
 
  virtual double threeBodyMatrixElement(const int imode, const Energy2 q2,
                                        const  Energy2 s3, const Energy2 s2,
                                        const Energy2 s1, const Energy m1,
                                        const Energy m2,const Energy m3) const;
 
  virtual void dataBaseOutput(ofstream & os,bool header) const;
 
public:
 
  void persistentOutput(PersistentOStream & os) const;
 
  void persistentInput(PersistentIStream & is, int version);
 
  static void Init();
 
protected:
 
  virtual IBPtr clone() const {return new_ptr(*this);}
 
  virtual IBPtr fullclone() const {return new_ptr(*this);}
  
protected:
  
  virtual void doinit();
 
  virtual void doinitrun();
 
private:
 
  EtaPiGammaGammaDecayer & operator=(const EtaPiGammaGammaDecayer &) = delete;
 
private:
 
  InvEnergy _grhoomega;
 
  Energy _fpi;
 
  Energy _rhomass;
 
  Energy _rhowidth;
 
  double _grho;
 
  Energy _mpi;
 
  double _rhoconst;
 
  bool _localparameters;
 
  double _ratiofpif8;
 
  double _ratiofpif0;
 
  double _theta;
 
  double _etamax;
 
  double _etapmax;
 
  vector<InvEnergy2> _dconst;
 
  vector<InvEnergy2> _econst;
 
  mutable RhoDMatrix _rho;
 
  mutable vector<Helicity::LorentzPolarizationVector> _vectors[2];
};
 
}
 
 
#endif /* HERWIG_EtaPiGammaGammaDecayer_H */