Initial and final state radiation Initial and final state radiation In particle physics, initial and final state radiation refers to certain kinds of radiative emissions that are not due to particle annihilation. It is important in experimental and theoretical studies of interactions at particle colliders. Particle accelerators and colliders produce collisions (interactions) of particles (like the electron or the proton). In the terminology of the quantum state, the colliding particles form the "Initial State". In the collision, particles can be annihilated or/and exchanged, producing possibly different sets of particles, the "Final States". The Initial and Final States of the interaction relate through the so-called scattering
Comparison of chemistry and physics studies the properties of matter at a larger scale (for example, astrochemistry) and the reactions of matter at a larger scale (for example, technical chemistry), but typically, explanations and predictions are related back to the underlying atomic structure, giving more emphasis on the methods for the identification of molecules and their mechanisms of transformation than any other science. Although both physics and chemistry are concerned with matter and its interaction with energy, the two disciplines differ in approach. In physics, it is typical to abstract from the specific type of matter, and to focus on the common properties of many