Semi-inclusive deep-inelastic scattering on a polarized spin-1 target. II. Deuteron and spectator nucleon tagging

TL;DR

This paper develops a theoretical framework for semi-inclusive deep-inelastic scattering on polarized spin-1 targets, specifically the deuteron, incorporating spectator nucleon tagging to analyze nuclear structure and spin effects at high energies.

Contribution

It introduces a light-front quantization approach to describe the deuteron’s wave function and computes tagged structure functions within the impulse approximation, advancing the understanding of polarized nuclear targets.

Findings

Tensor-polarized spin asymmetries of order unity at 300 MeV spectator momentum

Derived sum rules for tagged spin structure functions

Framework applicable to future experiments at Jefferson Lab and EIC

Abstract

We develop the theoretical framework for semi-inclusive deep-inelastic scattering on a polarized spin-1 target and apply it to scattering on the polarized deuteron with spectator nucleon tagging. In Part I (previous article) we present the general form of the semi-inclusive cross section and polarization observables for the spin-1 target. In Part II (this article) we consider deep-inelastic scattering on the polarized deuteron with spectator nucleon tagging as a special case of target fragmentation. Methods of light-front quantization are employed to separate nuclear and hadronic structure in the high-energy process and achieve a composite description. The light-front wave function of the polarized deuteron is obtained from a rotationally covariant 3-dimensional wave function in the center-of-mass frame of the proton-neutron system. The tagged structure functions are computed in the impulse approximation. The momentum and spin distribution of the active nucleon are controlled by the deuteron polarization and the detected spectator momentum ($D/S$ wave ratio). The cross section and spin asymmetries are evaluated for general deuteron polarization (vector and tensor, longitudinal and transverse) as functions of the spectator momentum. Tensor-polarized spin asymmetries of order unity are achieved for spectator momenta $\sim$ 300 MeV, which select configurations with large $D$-wave. Sum rules for the tagged spin structure functions are derived. The results can be used for simulations of spectator tagging in future polarized fixed-target experiments (Jefferson Lab) or at the Electron-Ion Collider.