Precision Measurement of the n-3He Incoherent Scattering Length Using Neutron Interferometry

TL;DR

This paper presents the first neutron interferometry measurement of the neutron-$^3$He incoherent scattering length, providing a precise value that supports nuclear potential models and demonstrates the use of polarized targets in interferometry.

Contribution

It introduces the first measurement of the neutron-$^3$He incoherent scattering length using neutron interferometry with a polarized nuclear target.

Findings

Measured scattering length: -2.512 ± 0.012 (stat) ± 0.014 (sys) fm

Results agree with recent theoretical calculations

Demonstrated the use of polarized targets in neutron interferometry

Abstract

We report the first measurement of the low-energy neutron-$^3$He incoherent scattering length using neutron interferometry: $b_i' = (-2.512\pm 0.012{statistical}\pm0.014{systematic})$ fm. This is in good agreement with a recent calculation using the AV18+3N potential. The neutron-$^3$He scattering lengths are important for testing and developing nuclear potential models that include three nucleon forces, effective field theories for few-body nuclear systems, and neutron scattering measurements of quantum excitations in liquid helium. This work demonstrates the first use of a polarized nuclear target in a neutron interferometer.