We report on a study of the longitudinal to transverse cross section ratio, $R=\sigma_L/\sigma_T$, at low values of $x$ and $Q^{ 2}$, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Lab Hall C spanning the four-momentum transfer range 0.06 $ < Q^{ 2} < 2.8$ GeV$^{ 2}$. Even at the lowest values of $Q^{ 2}$, $R$ remains nearly constant and does not disappear with decreasing $Q^{ 2}$, as expected. We find a nearly identical behaviour for hydrogen and deuterium.
Categories: nucl-ex