Herwig7HepMC.cxx

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// -*- C++ -*-
/*
  Copyright (C) 2002-2026 CERN for the benefit of the ATLAS collaboration
*/
 

 
 
#include "ThePEG/EventRecord/Event.h"
#include "ThePEG/EventRecord/SubProcess.h"
#include "ThePEG/Handlers/XComb.h"
#include "ThePEG/Handlers/EventHandler.h"
#include "ThePEG/PDF/PDF.h"
 
#include "Herwig/API/HerwigAPI.h"
#include "AtlasHepMC/AttributeNames.h"

#define HEPMC_HAS_CROSS_SECTION
#define HEPMC_HAS_PDF_INFO
#define HAVE_HEPMC3 1
 
#include "ThePEG/Vectors/HepMCConverter.h"
#ifdef HWVER_IS_72
#include "HepMC3/GenEvent.h"
#include "HepMC3/GenParticle.h"
#include "HepMC3/GenVertex.h"
namespace ThePEG {
  template<>
  struct HepMCTraits<HepMC3::GenEvent>
    : public HepMCTraitsBase<HepMC3::GenEvent,
                             HepMC3::GenParticle,
                             HepMC3::GenParticlePtr,
                             HepMC3::GenVertex,
                             HepMC3::GenVertexPtr,
                             std::pair<double,double>,
                             HepMC3::GenPdfInfo>
  {
    static bool hasUnits() {
      return true;
    }
 

  static void setScaleAndAlphas(HepMC3::GenEvent & e, Energy2 scale,
                double aS,  double aEM, Energy unit) {
    e.add_attribute(HepMCStr::event_scale,std::make_shared<HepMC3::DoubleAttribute>(sqrt(scale)/unit));
    e.add_attribute(HepMCStr::alphaQCD,std::make_shared<HepMC3::DoubleAttribute>(aS));
    e.add_attribute(HepMCStr::alphaQED,std::make_shared<HepMC3::DoubleAttribute>(aEM));
  }

  static void setSignalProcessVertex(HepMC3::GenEvent & e, HepMC3::GenVertexPtr v) {
  e.add_attribute(HepMCStr::signal_process_vertex,std::make_shared<HepMC3::IntAttribute>(v->id()));
  }

  static void setPolarization(HepMC3::GenParticle & genp, double the, double phi) {
    genp.add_attribute(HepMCStr::theta,std::make_shared<HepMC3::DoubleAttribute>(the));
    genp.add_attribute(HepMCStr::phi,std::make_shared<HepMC3::DoubleAttribute>(phi));
  }

  static void setColourLine(HepMC3::GenParticle & p, int indx, int coline) {
      p.add_attribute(HepMCStr::flow + std::to_string(indx),std::make_shared<HepMC3::IntAttribute>(coline));
  }
  static void setBeamParticles(HepMC3::GenEvent & e, HepMC3::GenParticlePtr p1, HepMC3::GenParticlePtr p2) {
    p1->set_status(4);
    p2->set_status(4);
    e.set_beam_particles(std::move(p1),std::move(p2));
  }
  
    static HepMC3::GenParticlePtr newParticle(const Lorentz5Momentum & p,
                 long id, int status, Energy unit) {
    // Note that according to the documentation the momentum is stored in a
    // HepLorentzVector in GeV (event though the CLHEP standard is MeV).
    LorentzVector<double> p_scalar = p/unit;
   HepMC3::GenParticlePtr genp = std::make_shared<HepMC3::GenParticle>(HepMC::FourVector(p_scalar.x(),p_scalar.y(),p_scalar.z(),p_scalar.e()), id, status);
   genp->set_generated_mass(p.mass()/unit);
    return genp;
  }
  static void setPosition( HepMC3::GenVertex & v, const LorentzPoint & p, Length unit) {
    LorentzVector<double> p_scaled = p/unit;
    v.set_position(HepMC::FourVector(p_scaled.x(),p_scaled.y(),p_scaled.z(),p_scaled.t()));
  }
  
  static HepMC3::GenVertexPtr newVertex() {
    return  std::make_shared<HepMC3::GenVertex>();
  }
    };
}
#else
namespace ThePEG {
  template<>
  struct HepMCTraits<HepMC::GenEvent>
    : public HepMCTraitsBase<HepMC::GenEvent,
                             HepMC::GenParticle,
                             HepMC::GenVertex,
                             HepMC::Polarization,
                             HepMC::PdfInfo>
  {
    static bool hasUnits() {
      return true;
    }
  };
}
#endif
  
void   convert_to_HepMC(const ThePEG::Event & event, HepMC::GenEvent & evt, bool nocopies,ThePEG::Energy eunit, ThePEG::Length lunit){
  ThePEG::HepMCConverter<HepMC::GenEvent>::convert(event, evt, nocopies, eunit, lunit);
}