# Bjorken Scaling and the Parton Model

It is often said that Bjorken scaling of the deep inelastic structure functions $$\nu W_2(\nu ,Q^2)\rightarrow F(x)$$ (where $Q^2$ is the virtuality of the photon, $\nu=\frac{P\cdot q}{M_N}$ is the energy imparted to the nucleon of mass $M_N$ in the lab frame and the arrow indicates the Bjorken limit in which $Q^2,\nu\rightarrow \infty$ with $x=\frac{Q^2}{2P\cdot q}$ held fixed) indicates that the photon is scattering elastically off of free constituents of the nucleon.

My question is the following:

What would scattering off of a bound state of particles with a large coupling parameter look like (this is in juxtaposition to QCD where the constituents are free at short distances)? What approximations would be dropped compared to QCD: would the sum over amplitudes still be incoherent? Would the scattering still be elastic (prior to hadronization)? Could one compute the scattering as scattering off of the individual constituents?