Inclusive electron-proton and electron-deuteron inelastic cross sections have been measured at Jefferson Lab (JLab) in the resonance region, at large Bjorken x, up to 0.92, and four-momentum transfer squared Q 2 up to 7.5 GeV 2 in the experiment E00-116. These measurements are used to extend to larger x and Q 2 precision, quantitative, studies of the phenomenon of quark-hadron duality. Our analysis confirms, both globally and locally, the apparent "violation" of quark-hadron duality previously observed at a Q 2 of 3.5 GeV 2 when resonance data are compared to structure function data created from CTEQ6M and MRST2004 parton distribution functions (PDFs). More importantly, our new data show that this discrepancy saturates by Q 2 ∼ 4 Gev 2 , becoming Q 2 independent. This suggests only small violations of Q 2 evolution by contributions from the highertwist terms in the resonance region which is confirmed by our comparisons to ALEKHIN and ALLM97. We conclude that the unconstrained strength of the CTEQ6M and MRST2004 PDFs at large x is the major source of the disagreement between data and these parameterizations in the kinematic regime we study and that, in view of quark-hadron duality, properly averaged resonance region data could be used in global QCD fits to reduce PDF uncertainties at large x.

%'e report high resolution measurements of inelastic electron scattering to all narrow normalparity states of '60 up to 12.05 MeV, which include states with J"(E"MeV): 0~+(6.049),The measurements were performed primarily at 90' and 160' and span momentum transfers between 0.6 and 2.6 fm '. Improved line shape fitting techniques have been developed. These are the first electron scattering measurements for the 4~+ state and of second form-factor maxima for several states. The form factor for excitation of the 2+2 state is strikingly different from that of the other 2+ states and indicates a transition density peaked in the interior. Transition charge densities were extracted from a combined data set that includes earlier electron scattering data renormalized to a recent analysis of elastic scattering from ' O. Comparisons have been made with several structure models, including the Brown-Green model, the weak-coupling model, a Pun shell model, and the tetrahedral alpha-cluster model.

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