EtaPiPiDefaultCurrent.h

// -*- C++ -*-
//
// EtaPiPiDefaultCurrent.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_EtaPiPiDefaultCurrent_H
#define HERWIG_EtaPiPiDefaultCurrent_H
//
// This is the declaration of the EtaPiPiDefaultCurrent class.
//
#include "WeakCurrent.h"
#include "Herwig/Utilities/Interpolator.h"
#include "Herwig/Utilities/Kinematics.h"
#include "ThePEG/StandardModel/StandardModelBase.h"
#include "Herwig/Decay/ResonanceHelpers.h"
#include <numeric>
 
namespace Herwig {
using namespace ThePEG;
 
class EtaPiPiDefaultCurrent: public WeakCurrent {
 
public:
 
  EtaPiPiDefaultCurrent();
 
  virtual vector<LorentzPolarizationVectorE> 
  current(tcPDPtr resonance,
          FlavourInfo flavour,
          const int imode, const int ichan,Energy & scale,
          const tPDVector & outgoing,
          const vector<Lorentz5Momentum> & momenta,
          DecayIntegrator::MEOption meopt) const;
 
  virtual bool accept(vector<int> id);
 
  virtual unsigned int decayMode(vector<int> id);
 
  virtual tPDVector particles(int icharge, unsigned int imode, int iq, int ia);
 
public:
 
  void persistentOutput(PersistentOStream & os) const;
 
  void persistentInput(PersistentIStream & is, int version);
 
  static void Init();
 
public:
 
  virtual bool createMode(int icharge, tcPDPtr resonance,
                          FlavourInfo flavour,
                          unsigned int imode,PhaseSpaceModePtr mode,
                          unsigned int iloc,int ires,
                          PhaseSpaceChannel phase, Energy upp );
 
  virtual void dataBaseOutput(ofstream & os,bool header,bool create) const;
 
protected:
 
  virtual IBPtr clone() const {return new_ptr(*this);}
 
  virtual IBPtr fullclone() const {return new_ptr(*this);}
 
protected:
 
  virtual void doinit();
 
private:
 
  EtaPiPiDefaultCurrent & operator=(const EtaPiPiDefaultCurrent &) = delete;
 
private:
  
  Complex BrhoF123(Energy2 q2,int ires) const {
    Complex output(0.);
    Complex norm = std::accumulate(_rhoF123wgts.begin(),_rhoF123wgts.end(),Complex(0.));
    if(ires<0) {
      for(unsigned int ix=0;ix<_rhoF123wgts.size();++ix) {
        output+=_rhoF123wgts[ix]*
          Resonance::BreitWignerPWave(q2,_rhoF123masses[ix],
                                      _rhoF123widths[ix],_mpi,_mpi);
      }
    }
    else {
      assert(ires<=int(_rhoF123wgts.size()));
      output=_rhoF123wgts[ires]*
        Resonance::BreitWignerPWave(q2,_rhoF123masses[ires],
                                    _rhoF123widths[ires],_mpi,_mpi);
    }
    return output/norm;
  }
 
  Complex BrhoF5(Energy2 q2,int ires) const {
    Complex output(0.);
    Complex norm = std::accumulate(_rhoF5wgts.begin(),_rhoF5wgts.end(),Complex(0.0));
    if(ires<0) {
      for(unsigned int ix=0;ix<_rhoF5wgts.size();++ix) {
        output+=_rhoF5wgts[ix]*
          Resonance::BreitWignerPWave(q2,_rhoF5masses[ix],
                                      _rhoF5widths[ix],_mpi,_mpi);
      }
    }
    else {
      assert(ires<=int(_rhoF123wgts.size()));
      output=_rhoF5wgts[ires]*
        Resonance::BreitWignerPWave(q2,_rhoF5masses[ires],
                                    _rhoF5widths[ires],_mpi,_mpi);
    }
    return output/norm;
  }
 
private:
  
  vector<double> _rhoF123wgts;
  
  vector<double> _rhoF5wgts;
 
  Energy _fpi;
 
  Energy _mpi;
 
  vector<Energy> _rhoF123masses;
 
  vector<Energy> _rhoF5masses;
 
  vector<Energy> _rhoF123widths;
 
  vector<Energy> _rhoF5widths;
};
 
}
 
#endif /* HERWIG_EtaPiPiDefaultCurrent_H */