Answer:
The Clebsh-Gordan Coefficients to relate the coupled and uncoupled bases.
Step-by-step explanation:
In quantum mechanics, two different sources of angular momentum eigenstates, show their widening through the Clebsch–Gordan (CG) coefficients, first in an uncoupled product bases.
- The uncoupled basis writes the state as eigenstates of the z-components of the two particles:
IS1+S2ms1ms2)
- The coupled basis writes the state as eigenstates of the two particles:
IS1S2Stotms)