I did some furhter investigations last night and believe
that I now understand the reason why Ryckebusch gets such a
large cross section for pm ~ 280 MeV/c.  I compared several
calculations sing his wave function.  If I use a central 
Woods-Saxon optical potential with 50 MeV depth that is purely
real, the ratio to a standard DWIA calculation (such as EDAIO
optical potential) shows a dramatic peak at about 280 MeV/c.
For small pm, omitting the absorptive potential gives a
relatively constant ratio of about 2, but near 280 MeV/c there
is a peak that rises to about 12, before falling below 1 for
pm > 400 MeV/c.  The location of this peak is probably related
to the diffuseness of the potential, occurring at something like
twice the Fermi momentum -- these scales are closely related.
If you examine Ryckebusch/Kelly in the paper, you will find that
the ratio increase with pm, becoming largest near 280, then
decreasing again.  The effect show some sensitivity to the 
choice of current operator, with nonrelativistic operators
producing +/- 25% changes, but do not affect the qualitative
appearance of this strong peak.

The p-shell states show similar ratios versus pm, with 
minor shifts of position in this peak.  Nilanga -- do you have
Jan's p-shell results?  I will try to obtain Jan's potential and
his p-shell results by e-mail rather than phone call.  I expect
that his p-shell calculations will show similar enhancements
near 300 MeV, enhancements which are much too large to be 
consistent with the data where the stanard DWIA works well.
I may try to call him next week, but I think that a more clear
comparison can be made by exchanging e-mail with figures that
I can prepare better at home.  In the meantime, I have a crude
figure to show this afternoon.