Vol 3 - Landau, Lifshitz - Quantum mechanics - non-relativistic theory (3ed., 1991) · Problem 55.2

Spin

Physics — Landau & Lifshitz · spin-scalar-product-two-particles

Problem

Determine the values of the scalar product

\mathbf{s}_1 \cdot \mathbf{s}_2

of spins (i) of two particles in states in which the total spin of the system,

S = \mathbf{s}_1 + \mathbf{s}_2

, has definite values (0 or 1).