Measurement of the Vector and Tensor Asymmetries at Large Missing Momentum in Quasielastic $(\vec{e}, e^{\prime}p)$ Electron Scattering from Deuterium

TL;DR

This study measures vector and tensor asymmetries in quasielastic electron scattering from deuterium at high missing momentum, providing insights into the deuteron's internal structure and testing theoretical models.

Contribution

It presents new experimental data on asymmetries at large missing momentum, directly probing the deuteron's D-wave component and neutron-proton interactions.

Findings

A^V_{ed} crosses zero at ~320 MeV/c missing momentum.

A^T_d is dominated by tensor force effects.

Data strongly constrain theoretical models.

Abstract

We report the measurement of the beam-vector and tensor asymmetries $A^V_{ed}$ and $A^T_d$ in quasielastic $(\vec{e}, e^{\prime}p)$ electrodisintegration of the deuteron at the MIT-Bates Linear Accelerator Center up to missing momentum of 500~MeV/c. Data were collected simultaneously over a momentum transfer range $0.1< Q^2<0.5$~(GeV/c)$^2$ with the Bates Large Acceptance Spectrometer Toroid using an internal deuterium gas target, polarized sequentially in both vector and tensor states. The data are compared with calculations. The beam-vector asymmetry $A^V_{ed}$ is found to be directly sensitive to the $D$-wave component of the deuteron and have a zero-crossing at a missing momentum of about 320~MeV/c, as predicted. The tensor asymmetry $A^T_d$ at large missing momentum is found to be dominated by the influence of the tensor force in the neutron-proton final-state interaction. The new data provide a strong constraint on theoretical models.