BackshiftedFermiGasModel.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 "marley/LevelDensityModel.hh"
 
namespace marley {

  class BackshiftedFermiGasModel : public LevelDensityModel {
 
    public:

      BackshiftedFermiGasModel(int Z, int A);

      virtual double level_density(double Ex) override;

      virtual double level_density(double Ex, int two_J) override;

      virtual double level_density(double Ex, int two_J, marley::Parity Pi)
        override;
 
    protected:

      inline double compute_sigma_F2(double Ex, double a) {
        double U = Ex - Delta_BFM_;
 
        double sigma_F2 = 0.01389 * std::pow(A_, 5.0/3.0)
          * std::sqrt(a * U) / a_tilde_;
 
        return sigma_F2;
      }
 
      int Z_; 
      int A_; 
 
      double sigma_; 
 
      double a_tilde_; 
      double gamma_; 
      double delta_W_; 
      double Delta_BFM_; 

      double sigma_d_global_;
      double Sn_; 
  };
}