The Wigner-Eckart theorem gives a formal expression of its conservation.
The Wigner-Eckart theorem gives a formal expression of its conservation. Clebsch-Gordon coefficients are commonly used when this quantity is added. For a spherically symmetric potential, its expectation value must be constant in time. For an isolated system, the Hamiltonian is invariant under rotations, so this quantity is conserved. FTP, name this quantity which comes in orbital and spin varieties.
The Wigner-Eckart theorem gives a formal expression of its conservation.
{angular momentum}