Scaling violation in the separated response functions ofC12

The properties of deep inelastic electron scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ are analyzed in the context of relativistic $y$ scaling. A large enhancement of the transverse response relative to the longitudinal response is observed in the quasielastic region which is in contradiction to impulse approximation predictions assuming a free one-body current. Scaling behavior is recovered when a relativistic effective mass is included in the nucleon current operator. The first two moments of the longitudinal scaling function are also evaluated.