Quantum mechanical techniques for describing this process include the Born approximation and partial wave analysis. For 10 points each:
[10e] Name this process, in which a wave or particle interacts with an object and is forced to deviate from a straight trajectory.
ANSWER: scattering
[10m] In partial wave analysis, a wave is broken down into components with specific values of this quantity, and the scattering for each component is computed independently. The commutator of this quantity's x and y components equals i times h-bar times this quantity's z-component.
ANSWER: angular momentum [accept L, reject “momentum”]
[10h] The optical theorem states that the total cross-section of a scatterer equals 4 pi over the wavevector, all times this expression, evaluated at an angle of zero.
ANSWER: imaginary part of the forward scattering amplitude [or Im[f(0)] (“imaginary part of f of zero”); accept answers that additionally specify “zero-angle” or that the argument of the scattering amplitude is zero; prompt on answers like “the imaginary part of the amplitude”; reject answers that do not specify the imaginary part]
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