text: #ifndef GUARD_decay_h
  #define GUARD_decay_h
  
  #include "Particle.h"
  #include "Random.h"
  
  /*
   * decay.h and decay.cpp supplies a number of useful functions for calculating
   * decay kinematics.
   */
  
  
  void DecayDP (Particle &, Particle &);
  void DecayDM (Particle &, Particle &, Particle &, Particle &);
  void DecayDM_Off_Shell(Particle &daughter1, Particle &daughter2, Particle &mediato, Particle &parent, double theta);
  void TwoBodyDecay (Particle &parent, Particle &daughter1, Particle &daughter2);
  void TwoBodyDecay (Particle &parent, Particle &daughter1, Particle &daughter2, double thetad);
  void TwoBodyDecay (Particle &parent, Particle &daughter1, Particle &daughter2, double thetad, double phid);
  void Meson_Capture_Off_Shell(Particle &daughter1, Particle &daughter2, Particle &mediator, double theta);
  #endif
  
  