Analyzing power in elastic scattering of 6He from polarized proton target at 71 MeV/nucleon

TL;DR

This study measures the analyzing power in elastic scattering of 6He from polarized protons at 71 MeV/nucleon, revealing unique spin-orbit interaction features of neutron-rich helium isotopes.

Contribution

It introduces a new polarized proton target and applies multiple models to analyze the spin-orbit interaction in 6He scattering, highlighting differences from stable nuclei.

Findings

Spin-orbit potential for 6He is shallow and long-ranged.

Proton-alpha core interaction is crucial in scattering analysis.

Data supports a cluster-based and microscopic understanding of 6He interactions.

Abstract

The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a 6He nucleus. An optical model analysis revealed that the spin-orbit potential for 6He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with a alpha+n+n cluster folding model suggests that the interaction between a proton and the alpha core is essentially important in describing the p+6He elastic scattering. The data are also compared with fully microscopic analyses using non-local optical potentials based on nucleon-nucleon g-matrices.