Initial and final state radiation
Introduction
In [quantum field theory](/wiki/Quantum_field_theory "Quantum field theory"), **initial and final state radiation** refers to certain kinds of radiative emissions that are not due to [particle annihilation](/wiki/Particle_annihilation "Particle annihilation").[Radiative Corrections](http://www.phenix.bnl.gov/~manion/EIC/Tuesday/Tuesday_III/04_Schnatz.pptx), Peter Schnatz. Accessed 08 March 2013\.[Reducing the Uncertainty in the Detection Efficiency for Π0 Particles at BABAR](http://www.hep.manchester.ac.uk/u/kim/work/Poster.pdf), Kim Alwyn. Accessed 08 March 2013\. It is important in experimental and theoretical studies of interactions at particle colliders.


What is particle annihilation?