Measurement of R = longitudinal cross section/transverse cross section in the nucleon resonance region

Inclusive electron-proton inelastic cross sections have been measured in the nucleon resonance region at four-momentum transfer range between 0.2 and 5 (GeV/c)2 at Jefferson Lab. The data are utilized for precision measurement of R and the structure functions F2, F1, and F L in the resonance region. The results show that R exhibits resonance structure and the longitudinal resonant component is significant. The quark-hadron duality is verified for all unpolarized structure functions. A global fit to R and F 2 in this region is obtained.