DiscreteNuclearReaction.hh

//
// This file is part of MARLEY (Model of Argon Reaction Low Energy Yields)
//
// MARLEY is free software: you can redistribute it and/or modify it under the
// terms of version 3 of the GNU General Public License as published by the
// Free Software Foundation.
//
// For the full text of the license please see COPYING or
// visit http://opensource.org/licenses/GPL-3.0
//
// Please respect the MCnet academic usage guidelines. See GUIDELINES
// or visit https://www.montecarlonet.org/GUIDELINES for details.
 
#pragma once
#include <functional>
#include <map>
#include <memory>
#include <regex>
#include <string>
#include <vector>
 
#include "marley/CoulombCorrector.hh"
#include "marley/DecayScheme.hh"
#include "marley/Level.hh"
#include "marley/MassTable.hh"
#include "marley/MatrixElement.hh"
#include "marley/NuclearReaction.hh"
#include "marley/NuclearFormFactor.hh"
#include "marley/NucleonFormFactors.hh"
#include "marley/StructureDatabase.hh"
 
namespace marley {
 
  class Generator;
  class JSON;

  class DiscreteNuclearReaction : public NuclearReaction {
 
    public:

      DiscreteNuclearReaction( ProcessType pt, int pdg_a, int pdg_b,
        int pdg_c, int pdg_d, int q_d,
        const std::shared_ptr<std::vector<marley::MatrixElement> >& mat_els,
        CoulombCorrector::CoulombMode mode, const JSON& ff_config,
        const std::string& source_file );
 
      virtual std::shared_ptr< HepMC3::GenEvent > create_event(
        int particle_id_a, double KEa, marley::Generator& gen ) const override;

      void set_decay_scheme( marley::DecayScheme* scheme );

      virtual double total_xs( int pdg_a, double KEa ) const override;

      virtual double total_xs( int pdg_a, double KEa,
        marley::MatrixElement::TransitionType mat_el_type ) const;

      double diff_xs( const marley::MatrixElement& mat_el, double KEa,
        double cos_theta_c_cm, double& beta_c_cm,
        bool check_max_E_level ) const;

      virtual double diff_xs( int pdg_a, double KEa,
        double cos_theta_c_cm ) const;

      virtual double total_xs( const marley::MatrixElement& me, double KEa,
        double& beta_c_cm, bool check_max_E_level = true ) const;

      inline const std::vector< marley::MatrixElement >& matrix_elements() const
        { return *matrix_elements_; }
 
    protected:
 
      virtual void set_description() override;

      double sample_cos_theta_c_cm( const marley::MatrixElement& matrix_el,
        double KEa, double beta_c_cm, marley::Generator& gen ) const;

      double summed_xs_helper( int pdg_a, double KEa, double cos_theta_c_cm,
        std::vector<double>* level_xsecs, bool differential ) const;

      std::shared_ptr< std::vector<marley::MatrixElement> > matrix_elements_;

      std::pair< std::vector<int>, std::vector<double> > nucleon_radii_;

      CoulombCorrector coulomb_corrector_;

      NucleonFormFactors nucleon_form_factors_;

      std::shared_ptr< NuclearFormFactor > nuclear_ff_;

      bool allowed_approx_ = false;
  };
 
}