Cross section measurements of deuteron electro-disintegration at very high recoil momenta and large 4-momentum transfers (Q^2)

The $^{2}$H$(e,e'p)n$ cross sections have been measured at negative 4-momentum transfers of $Q^{2} = 4.5\pm0.5$ (GeV/c)$^{2}$ and $Q^{2} = 3.5\pm0.5$ (GeV/c)$^{2}$ reaching neutron recoil (missing) momenta up to $p_{\mathrm{r}}\sim$1.0 GeV/c. The data have been obtained at fixed neutron recoil angles $5^{\circ}\leq\theta_{nq}\leq95^{\circ}$ with respect to the 3-momentum transfer $\vec{q}$. The new data agree well with the previous data which reached $p_{\mathrm{r}}\sim550$ MeV/c. At $\theta_{nq}=35^{\circ}$ and $45^{\circ}$, final state interactions (FSI), meson exchange currents (MEC) and isobar configurations (IC) are suppressed and the plane wave impulse approximation (PWIA) provides the dominant cross section contribution. The new data are compared to recent theoretical calculations, and a significant disagreement for recoil momenta $p_{\mathrm{r}}>700$ MeV/c is observed.