PhotosFilter.cpp

Go to the documentation of this file.

/*
 *  CepGen: a central exclusive processes event generator
 *  Copyright (C) 2019-2022  Laurent Forthomme
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <Photos/Log.h>
#include <Photos/Photos.h>
#include <Photos/PhotosEvent.h>
#include <Photos/PhotosHepMC3Event.h>
 
#include "CepGen/Core/Exception.h"
#include "CepGen/Core/ParametersList.h"
#include "CepGen/Event/Event.h"
#include "CepGen/EventFilter/EventModifier.h"
#include "CepGen/Modules/EventModifierFactory.h"
#include "CepGen/Physics/PDG.h"
#include "CepGen/Utils/String.h"
#include "CepGenAddOns/HepMC3Wrapper/HepMC3EventInterface.h"
 
using namespace Photospp;
 
namespace cepgen {
  namespace hadr {
    class PhotosFilter : public EventModifier {
    public:
      explicit PhotosFilter(const ParametersList&);
      ~PhotosFilter();
 
      static ParametersDescription description();
 
      void initialise() override;
      bool run(Event& ev, double& weight, bool fast) override;
    };
 
    PhotosFilter::PhotosFilter(const ParametersList& params) : EventModifier(params) {
      if (steer<bool>("debug"))
        Log::LogAll(true);
      Photos::setMomentumConservationThreshold(1.e-10);
      Photos::maxWtInterference(steer<double>("maxWtInterference"));
      Photos::setInfraredCutOff(steer<double>("infraredCutOff"));
      Photos::setInterference(steer<bool>("interference"));
      Photos::setDoubleBrem(steer<bool>("doubleBrem"));
      Photos::setQuatroBrem(steer<bool>("quatroBrem"));
      Photos::setCorrectionWtForW(steer<bool>("correctionWtForW"));
      Photos::setExponentiation(steer<bool>("exponentiation"));
      Photos::setPairEmission(steer<bool>("pairEmission"));
      Photos::setPhotonEmission(steer<bool>("photonEmission"));
      Photos::setMeCorrectionWtForScalar(steer<bool>("meCorrectionWtForScalar"));
      Photos::setMeCorrectionWtForW(steer<bool>("meCorrectionWtForW"));
      Photos::setMeCorrectionWtForZ(steer<bool>("meCorrectionWtForZ"));
      Photos::setTopProcessRadiation(steer<bool>("topProcessRadiation"));
    }
 
    PhotosFilter::~PhotosFilter() { Log::SummaryAtExit(); }
 
    void PhotosFilter::initialise() {
      Photos::setMomentumUnit(Photos::GEV);
      Photos::setAlphaQED(constants::ALPHA_EM);
      Photos::initialize();
    }
 
    bool PhotosFilter::run(Event& ev, double& weight, bool) {
      weight = 1.;
 
      HepMC3::CepGenEvent hepmc_evt(ev);
      PhotosHepMC3Event evt(&hepmc_evt);
      //evt.dump();
      evt.process();
      hepmc_evt.merge(ev);
      ev.dump();
 
      return true;
    }
 
    ParametersDescription PhotosFilter::description() {
      auto desc = EventModifier::description();
      desc.add<bool>("debug", false).setDescription("log all debugging information?");
      desc.add<double>("maxWtInterference", 1.).setDescription("maximum interference weight");
      desc.add<double>("infraredCutOff", 0.01)
          .setDescription("minimal energy (in units of decaying particle mass) for photons to be explicitly generated");
      desc.add<bool>("interference", true).setDescription("key for interference, matrix element weight");
      desc.add<bool>("doubleBrem", true).setDescription("set double bremsstrahlung generation");
      desc.add<bool>("quatroBrem", false).setDescription("set bremsstrahlung generation up to multiplicity of 4");
      desc.add<bool>("correctionWtForW", true)
          .setDescription("key for partial effects of matrix element (in leptonic W decays)");
      desc.add<bool>("exponentiation", true).setDescription("set exponentiation mode");
      desc.add<bool>("pairEmission", false).setDescription("set pair emission");
      desc.add<bool>("photonEmission", true).setDescription("set photon emission");
      desc.add<bool>("meCorrectionWtForScalar", false)
          .setDescription("switch for complete effects of the matrix element (in scalar to two scalar decays)");
      desc.add<bool>("meCorrectionWtForW", false)
          .setDescription("switch for complete effects of matrix element (in leptonic W decays)");
      desc.add<bool>("meCorrectionWtForZ", false)
          .setDescription("switch for complete effects of matrix element (in leptonic Z decays)");
      desc.add<bool>("topProcessRadiation", true)
          .setDescription("set photon emission in top pair production in quark (gluon) pair annihilation");
      return desc;
    }
  }  // namespace hadr
}  // namespace cepgen
 
// register event modifier
typedef cepgen::hadr::PhotosFilter PhotosFilter;
REGISTER_MODIFIER("photos", PhotosFilter);