Probing the Deuteron at Very Large Internal Momenta

TL;DR

This study measures deuteron electrodisintegration cross sections at high internal momenta, providing new data that tests theoretical models and reveals discrepancies at momenta above 700 MeV/c.

Contribution

It extends previous measurements of deuteron structure to higher recoil momenta, offering new experimental data for testing nuclear interaction theories.

Findings

Data agree with previous measurements up to 500 MeV/c

At high momenta, discrepancies with theoretical calculations become significant

Final state interactions are suppressed at certain recoil angles, simplifying analysis

Abstract

$^{2}\mathrm{H}(e,e'p)n$ cross sections have been measured at 4-momentum transfers of $Q^{2} = 4.5 \pm 0.5$ (GeV/c)$^{2}$ over a range of neutron recoil momenta, $p_{\mathrm{r}}$, reaching up to $\sim1.0$ GeV/c. The data were obtained at fixed neutron recoil angles $\theta_{nq} = 35^\circ$, $45^\circ$ and $75^{\circ}$ with respect to the 3-momentum transfer $\vec q$. The new data agree well with previous data which reached $p_{\mathrm{r}}\sim500$ MeV/c. At $\theta_{nq} = 35^\circ$ and $45^\circ$, final state interactions (FSI), meson exchange currents (MEC) and isobar currents (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, where we observe a significant discrepancy for missing momenta $p_{\mathrm{r}}>700$ MeV/c.