Nuclear modification of transverse-longitudinal structure function ratio

We investigate the nuclear effects on the transverse and longitudinal responses in the deep inelastic region due to the nuclear binding and nucleon Fermi motion. We display the role of the transverse-longitudinal admixture due to the transverse nucleon momentum. The mixing effect is appreciable at small Q(2) values, and gradually disappears at large Q(2) values. The nuclear modification is then dominated by the binding and Fermi-motion effects which are contained in the spectral function.