We have separated the longitudinal $\left(f_{00}\right)$, transverse $\left(f_{11}\right)$, and longitudinal-transverse interference $\left(f_{01}\right)$ structure functions in the ${}^2\mathrm{H}\left({e,e}^{\prime }p\right)n$ reaction at $|\overrightarrow{q}|\approx 400\mathrm{MeV}/c$ and $\omega \approx 110\mathrm{MeV}$. A nonrelativistic calculation which includes effects due to final state interactions, meson exchange currents, and isobar configurations agrees with the measured $f_{11}$ and $f_{01}$ but overpredicts $f_{00}$ by 25% ( $2\sigma$). The data are also compared to the results of previous structure function measurements.

• Received 24 July 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.1579