Off-forward parton distributions and impact parameter dependent parton   structure
  The connection between parton distributions as a function of the impact parameter and off-forward parton distributions is discussed in the limit of vanishing skewedness parameter $\xi$, i.e. when the off-forwardness is purely transverse. It is also illustrated how to relate $\xi\neq 0$ data to $\xi=0$ data, which is important for experimental measurements of these observables. 
M. Burkardt (New Mexico State University)