Inelastic Electron-Proton Scattering at Large Momentum Transfers and the Inelastic Structure Functions of the Proton

Differential cross sections for electrons scattered inelastically from hydrogen have been measured at 18°, 26°, and 34°. The range of incident energy was 4.5 to 18 GeV, and the range of four-momentum transfer squared was 1.5 to 21 ${\left(\frac{\mathrm{GeV}}{c}\right)}^2$. With the use of these data in conjunction with previously measured data at 6° and 10°, the contributions from the longitudinal and transverse components of the exchanged photon have been separately determined. The values of the ratio of the photoabsorption cross sections $\frac{{\sigma }_S}{{\sigma }_T}$ are found to lie in the range 0 to 0.5. The question of scaling of $2M_p{W}_1$ and $\nu W_2$ as a function of $\omega$ is discussed, and scaling is verified for a large kinematic range. Also, a new scaling variable which reduces to $\omega$ in the Bjorken limit is introduced which extends the scaling region. The behavior of ${\sigma }_T$ and ${\sigma }_S$ is also discussed as a function of $\nu$ and $q^2$. Various weighted sum rules of $\nu W_2$ are evaluated.