Investigation of Medium Modifications to ^{12}C Structure Functions in the Resonance Region.

We present results from a high precision experimental study of the nuclear modification of the longitudinal (F_{L}) to transverse (F_{1}) structure function ratio for bound nucleons in the resonance region. The inclusive electron scattering cross sections were measured in Jefferson Lab Experimental Hall C on carbon and deuterium nuclei for a large range of kinematics, allowing for separations of the longitudinal and transverse structure functions to be performed at a range of four-momentum transfer values 0.5≤Q^{2}≤3.75  GeV^{2}. In contrast to the significant body of measurements of the nuclear modification of the F_{2} structure function in the deep inelastic scattering region, there is very little on F_{L} and R=F_{L}/2xF_{1} in the region of the nucleon resonances. In this Letter we present measurements of the nuclear effect on R for ^{12}C (R_{C}) relative to deuterium (R_{D}). These results indicate regions in which in R_{C}>R_{D}, requiring that the nuclear modifications be different in all three structure functions, F_{2}, F_{1}, and F_{L}.