Elementary Particle Theory Volume 2 Quantum Electrodynamics pdf
Elementary Particle Theory Volume 2 Quantum Electrodynamics pdf : Pages 217
By Eugene Stefanovich
In a successful theory of elementary particles, at least three important conditions must be fulfilled :
(1) relativistic invariance in the instant form of dynamics;
(2) cluster separability of the interaction;
(3) description of processes involving creation and destruction of particles.
In the first volume of our book we discussed interacting quantum theories in Hilbert spaces with a fixed set of particles. We showed how it is possible to satisfy the first two requirements (relativistic invariance and cluster separability).1 However, these theories were fundamentally incomplete, due to their inability to describe physical processes that change the types and/or number of particles in the system. Thus, condition
3 from our list was not fulfilled.
Familiar examples of the creation and annihilation processes are emission and absorption of light (photons), decays, neutrino oscillations, etc. Particles are produced especially intensively at high energies. This is due to the famous Einstein formula E = mc2, which says, in particular, that if the system has sufficient energy E of relative motion, then this energy can be transformed into the mass m of newly created particles. Even in the simplest two-particle case, the energy of the relative motion of these reactants is unlimited. Therefore, there is no limit to the number of new particles that can be created in a collision.
Series: Studies in Mathematical Physics 46
Publisher: de Gruyter, Year: 2019