We measured the inclusive electron-proton cross section in the nucleon resonance region $(W<\mathrm{}2.5\mathrm{}\mathrm{GeV})$ at momentum transfers $Q^2$ below $4.5(\mathrm{GeV}{/c)}^2$ with the CLAS detector. The large acceptance of CLAS allowed the measurement of the cross section in a large, contiguous two-dimensional range of $Q^2$ and x, making it possible to perform an integration of the data at fixed $Q^2$ over the significant x interval. From these data we extracted the structure function $F_2$ and, by including other world data, we studied the $Q^2$ evolution of its moments, $M_n{(Q}^2),$ in order to estimate higher twist contributions. The small statistical and systematic uncertainties of the CLAS data allow a precise extraction of the higher twists and will require significant improvements in theoretical predictions if a meaningful comparison with these new experimental results is to be made.

• Received 23 January 2003

DOI:https://doi.org/10.1103/PhysRevD.67.092001