First Measurements of Spin-Dependent Double-Differential Cross Sections and the GDH Integrand from \vec{^3He}(\vec{\gamma},n)pp at Incident Photon Energies of 12.8 and 14.7 MeV

TL;DR

This study presents the first measurements of spin-dependent cross sections for polarized ^3He photodisintegration at specific energies, providing crucial data to test and improve three-body nuclear interaction models.

Contribution

It reports the first experimental data on spin-dependent double-differential cross sections for polarized ^3He at 12.8 and 14.7 MeV, highlighting the significance of Coulomb interactions in theoretical models.

Findings

Data show the importance of Coulomb interactions in three-body calculations.

Results contribute to understanding the GDH sum rule for ^3He.

Experimental measurements align with advanced three-body theoretical predictions.

Abstract

The first measurement of the three-body photodisintegration of longitudinally-polarized ^3He with a circularly-polarized \gamma-ray beam was carried out at the High Intensity \gamma-ray Source (HI\gamma S) facility located at Triangle Universities Nuclear Laboratory (TUNL). The spin-dependent double-differential cross sections and the contributions from the three-body photodisintegration to the ^3He GDH integrand are presented and compared with state-of-the-art three-body calculations at the incident photon energies of 12.8 and 14.7 MeV. The data reveal the importance of including the Coulomb interaction between protons in three-body calculations.