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Homework Statement
Two particles with spin 1/2 and are in the spin state:
[itex] |\psi> = |\uparrow_{1}>|\downarrow_{2}> [/itex]
where [itex] |\uparrow_{1}> [/itex] is a state where particle 1 has spin up along the z-axis and
[itex] |\downarrow_{2}>[/itex] is a state where particle 2 is spin down along the z-axis.
If we measure the magnitude of the total spin of the two particles, what is the probability that the magnitude will be 1?
Homework Equations
[itex] Probability = |<n|\psi>|^{2} [/itex]
The Attempt at a Solution
I immediately thought that this problem was like a simple coin toss. 50% to get heads 50% to get tails. Since each particle has equal chance to be spin up or spin down, then the total probability of both being spin up after a measurement would be (0.5)(0.5) = 0.25 ?
This doesn't feel right to me. I feel like it should be more complicated. =/