marley_kinematics.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 <cmath>
 
#include "marley/Error.hh"
 
namespace HepMC3 {
  class GenParticle;
}
 
namespace marley_kinematics {
 
  // Lorentz boost a particle, replacing its energy and momentum with the
  // boosted versions
  void lorentz_boost( double beta_x, double beta_y, double beta_z,
    HepMC3::GenParticle& particle_to_boost );

  void two_body_decay(
    const std::shared_ptr< HepMC3::GenParticle >& initial_particle,
    std::shared_ptr< HepMC3::GenParticle >& first_product,
    std::shared_ptr< HepMC3::GenParticle >& second_product,
    double cos_theta_first, double phi_first );
 
  // Rotates a particle's 3-momentum so that it points in the (x, y, z)
  // direction
  void rotate_momentum_vector( double x, double y, double z,
    HepMC3::GenParticle& particle_to_rotate );
 
  // Gets the square of the total energy in the center of momentum frame for
  // two particles
  double get_mandelstam_s( const HepMC3::GenParticle& p1,
    const HepMC3::GenParticle& p2 );
 
  // Boost two particles into their mutual center-of-momentum frame
  void boost_to_cm_frame( HepMC3::GenParticle& p1, HepMC3::GenParticle& p2 );
}