American Journal of Physics
Eigenvalues of J2
Kenneth R. Brownstein
Abstract
Most derivations of the possible eigenvalues of J2 [i.e., h/2j (j + 1), j = 0, 1/2, 1, 3/2,...] rely upon the eigenvalues, h/m, of a component of J, say Jz. A derivation of the J2 eigenvalues is presented in which the concept of Jz eigenvalues does not appear. The derivation is based upon addition of angular momenta and the algebraic properties of the Pauli spin matrices.