PARTICLE PHYSICS

PARTICLE PHYSICS

Elementary particle physicists (“high-energy physicists”) study the fundamental particles of nature and the symmetries found in their interactions. The study of elementary particle physics is an important endeavor in its own right and beyond the scope of this book. But we need to use some of the concepts of this area of physics in our discussion of nuclei. Particles can be classified as fermions or bosons.

Fermions obey the Pauli principle and have antisymmetric wave functions and half-integer spins. (Neutrons, protons, and electrons are fermions.) Bosons do not obey the Pauli principle and have symmetric wave functions and integer spins. (Photons are bosons.) Particle groups, like fermions, can also be divided into the leptons (such as the electron) and the hadrons (such as the neutron and proton). The hadrons can interact via the nuclear or strong interaction while the leptons do not. (Both particle types can, however, interact via other forces, such as the electromagnetic force.) contains artistic conceptions of the standard model, a theory that describes these fundamental particles and their interactions. Examples of bosons, leptons, hadrons, their charges, and masses are given in. There are six different kinds of leptons (light particles) and they can be arranged in three pairs. The electron (e), the muon (m), and the tau lepton (t) each carry a charge of 2e and have associated with them the electron ( n e), muon ( n m), and tau neutrinos ( n t). These neutrinos are electrically neutral and have small or zero rest mass. The actual mass of the neutrinos is a subject of current research.

The electron neutrino is seen in nuclear phenomena such as b decay, whereas the other neutrinos are involved in higher energy processes. One important aspect of leptons is that their number is conserved in nuclear processes.

ANAΔΗΜΟΣΙΕΥΣΗ ΑΠΟ ΤΟ ΒΙΒΛΊΟ "MODERN NUCLEAR CHEMISTRY" ΤΩΝ:
WALTER D. LOVELAND Oregon State University
DAVID J. MORRISSEY Michigan State University
GLENN T. SEABORG University of California, Berkeley


    4/3/2016