Probing the Deuteron at Very Large Internal Momenta

Abstract

We measure $^{2}\mathrm{H}(e,{e}^{\ensuremath{'}}p)n$ cross sections at 4-momentum transfers of ${Q}^{2}=4.5\ifmmode\pm\else\textpm\fi{}0.5\text{ }\text{ }(\mathrm{GeV}/c{)}^{2}$ over a range of neutron recoil momenta ${p}_{r}$, reaching up to $\ensuremath{\sim}1.0\text{ }\text{ }\mathrm{GeV}/c$. We obtain data at fixed neutron recoil angles ${\ensuremath{\theta}}_{nq}=35\ifmmode^\circ\else\textdegree\fi{}$, 45\ifmmode^\circ\else\textdegree\fi{}, and 75\ifmmode^\circ\else\textdegree\fi{} with respect to the 3-momentum transfer $\stackrel{\ensuremath{\rightarrow}}{q}$. The new data agree well with previous data, which reached ${p}_{r}\ensuremath{\sim}500\text{ }\text{ }\mathrm{MeV}/c$. At ${\ensuremath{\theta}}_{nq}=35\ifmmode^\circ\else\textdegree\fi{}$ and 45\ifmmode^\circ\else\textdegree\fi{}, final state interactions, meson exchange currents, and isobar currents are suppressed and the plane wave impulse approximation provides the dominant cross section contribution. We compare the new data to recent theoretical calculations, where we observe a significant discrepancy for recoil momenta ${p}_{r}>700\text{ }\text{ }\mathrm{MeV}/c$.