Analyzing Power of 3 He(n, n)3 He Between 1.60 and 5.54 MeV


Conference Paper

We report the measurements of the analyzing power Ay(θ) of n-3He elastic scattering with unprecedented accuracy and angular coverage at five incident neutron energies between 1.60 and 5.54 MeV. To this end, we employed the polarization-transfer reactions 3H(p, n)3He and 2H(d, n)3He at 0° for neutron generation and a recently developed high-pressure 3He gas scintillator as an active target, enabling neutron-time-of-flight and 3He recoil-energy determinations. We obtained simultaneously the neutron polarization with a 4He-based polarimeter, capitalizing on the well-known n-4He Ay(θ). Our n-3He Ay(θ) data are compared to rigorous four-nucleon calculations using high-precision nucleon-nucleon potential models. The agreement between data and calculations is fair at the lower energies and becomes less satisfactory with increasing neutron energy. However, in comparison to the pure isotriplet p-3He system in the same energy region, the agreement between measured and calculated Ay is much better for the mixed (isotriplet and isosinglet) n-3He system, indicating large and somewhat counterintuitive isospin effects. We note that the incorporation of a Δ-mediated three-nucleon force in calculations of n-3He scattering was found to affect A y(θ) negligibly, suggesting the need for the reconsideration of fundamental interactions in resolving the four-nucleon analyzing power puzzle first established about a decade ago in p-3He scattering. © 2013 Springer-Verlag Wien.

Full Text

Duke Authors

Cited Authors

  • Esterline, J; Tornow, W

Published Date

  • August 1, 2013

Published In

Volume / Issue

  • 54 / 7-10

Start / End Page

  • 1323 - 1326

International Standard Serial Number (ISSN)

  • 0177-7963

Digital Object Identifier (DOI)

  • 10.1007/s00601-013-0595-3

Citation Source

  • Scopus