Quantum mechanics (angular momentum)

AI Thread Summary
The discussion focuses on calculating probabilities related to angular momentum in quantum mechanics using a specific wave function. The user seeks guidance on determining the probabilities P(lz = 0), P(lz = 2h), and P(lz = -2h) from the given wave function. They express confusion about applying the correct method for calculating these probabilities, as they are familiar with position probabilities and wavefunction collapse but not angular momentum states. The user references a previous attempt to express cos² in terms of PHI(m) states but finds their Mathematica code ineffective. The thread highlights the need for clarification on the relevant equations or concepts for angular momentum probability calculations.
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A particle is described by the wave function

\[CapitalPsi] (\[Rho], \[Phi]) =
AE^(-\[Rho]^2/2 \[CapitalDelta]^2) (Cos[\[Phi]])^2

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P (Subscript[l, z] = 0) = 2/3
P (Subscript[l, z] = 2 h) = 1/6
P (Subscript[l, z] = -2 h) = 1/6





I have already used

Subscript[\[CapitalPhi], m] (\[Phi]) = 1/Sqrt[2 \[Pi]] E^Im\[Phi]

as the problem suggests to express the cos^2 as PHI(sub m) states




I am simply brickwalled at how to calculate these probabilities. The only way I remember to calculate probabilities given a wavefunction is for position (probability of measuring the particle within a certain region). Or also, I remember how to find the probability of a wavefunction collapsing to a particular state if it is written as a linear combination of states. Can someone point me to the relevant equation or idea?
 
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Sorry, looks like that Mathematica code was no good.

Is it still legible?
 
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