<i>Angular Momentum in Quantum Mechanics</i>

TLDR

Angular momentum is a fundamental quantity in quantum mechanics, and this book offers a concise introduction to the topic. The book develops the theory of angular momentum by deriving quantization rules, spin and orbital components, Clebsch‑Gordan coefficients, spherical tensors, and 3‑j, 6‑j, and 9‑j symbols, and then applies these tools to practical problems such as partial‑wave expansions, particle emission and absorption, quadrupole moments, matrix‑element calculations, and symmetric‑top molecules.

Abstract

This book offers a concise introduction to the angular momentum, one of the most fundamental quantities in all of quantum mechanics. Beginning with the quantization of angular momentum, spin angular momentum, and the orbital angular momentum, the author goes on to discuss the Clebsch-Gordan coefficients for a two-component system. After developing the necessary mathematics, specifically spherical tensors and tensor operators, the author then investigates the 3-j, 6-j, and 9-j symbols. Throughout, the author provides practical applications to atomic, molecular, and nuclear physics. These include partial-wave expansions, the emission and absorption of particles, the proton and electron quadrupole moment, matrix element calculation in practice, and the properties of the symmetrical top molecule.