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Subatomic Physics

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6.11. More Details on Scattering and Structure 173<br />

Figure 6.23: Ratios of the nucleon structure functions deduced from F2(Cu)/F2(d) and<br />

F2(Fe)/F2(d). [From J. Ashman et. al., European Muon Collaboration, Phys. Lett. 202B,<br />

603 (1988).] Later data looks similar.<br />

fraction of what is actually used in research. Even so, it should provide some insight<br />

into the connection between scattering and structure.<br />

We begin the discussion with a simple case, nonrelativistic scattering by a fixed<br />

potential, V (x), and we approximate the incoming particle by a plane wave moving<br />

along the z axis, ψ =exp(ikz).<br />

The solution to the scattering problem is a solution of the time-independent<br />

Schrödinger equation,<br />

− �2<br />

2m ∇2ψ + Vψ= Eψ or (6.74)<br />

(∇ 2 + k 2 )ψ = 2m<br />

Vψ,<br />

�2 where the wave number k is related to the energy E by<br />

k = p<br />

�<br />

1 √<br />

= 2mE. (6.75)<br />

�<br />

Far away from the scattering center, the scattered wave will be spherical, and it<br />

will originate at the scattering center, which is assumed to be at the origin of<br />

the coordinate system. The total asymptotic wave function, shown in Fig. 6.25,<br />

consequently will be of the form<br />

ψ = e ikz + ψs, ψs = f(θ, ϕ) eikr<br />

. (6.76)<br />

r<br />

Thaler, Introduction to the Quantum Theory of Scattering, Academic Press, New York, 1967; W.O.<br />

Amrein, J.M. Jauch, K.B. Sinha, Scattering theory in quantum mechanics : physical principles<br />

and mathematical methods, Reading, Mass. : W. A. Benjamin, Advanced Book Program, 1977.

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