Addition of Angular Momentum for identical particles

AI Thread Summary
For two identical spin-1 particles without orbital angular momentum, the addition of angular momentum leads to total spin states of j=0, 1, and 2. The distinction between distinguishable and identical particles is crucial, as the total state must be (anti-)symmetric based on Bose or Fermi statistics. To construct the states for j=0 and j=1, one must consider both the spin states and the spatial wave function. The states for j=1 can be derived from the same basis states used for j=2, highlighting the importance of symmetry in the overall state. Understanding these principles is essential for accurately describing the behavior of identical particles in quantum mechanics.
Gabriel Maia
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This is the problem I'm trying to understand:

Consider two particles with spin 1 without orbital angular momentum. If they are distinguishable, from the rule of addition of angular momentum applied to spin, we'll have states of total spin j=0,1,2. If we have, however, identical particles which are the possible states?

In textbooks, the addition of angular momentum is never treated in terms of distinguishable and identical particles, at least I don't recall it. The way I would approach this problem is to acknowledge that the possible total spin would be j=0,1,2 and then, from the state |-1\rangle |-1\rangle, I would use the ladder operator to build all the other four states compatible with j=2. How do I build the states for j=0,1? The state |j=1,m_{j}=-1\rangle must be built from the same states as |j=2,m_{j}=-1\rangle, that is, |-1\rangle |0\rangle and |0\rangle |-1\rangle. So how are they any different?

Thank you very much.

The Attempt at a Solution

 
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What is important for distinguishable particles is that the total state is (anti-)symmetric (depending on Bose/Fermi statistics). You need to take the spin state into account as well as the spatial wave function.
 
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