Double Polarized Neutron-Proton Scattering and Meson-Exchange Nucleon-Nucleon Potential Models

B. W. Raichle; C. R. Gould; D. G. Haase; M. L. Seely; J. R. Walston; W. Tornow; W. S. Wilburn; S. I. Penttilä; G. W. Hoffmann

doi:10.1103/PhysRevLett.83.2711

Double Polarized Neutron-Proton Scattering and Meson-Exchange Nucleon-Nucleon Potential Models

B. W. Raichle, C. R. Gould, D. G. Haase, M. L. Seely, J. R. Walston, W. Tornow, W. S. Wilburn, S. I. Penttilä, and G. W. Hoffmann

Phys. Rev. Lett. 83, 2711 – Published 4 October 1999

Abstract

We report on polarized beam–polarized target measurements of the spin-dependent neutron-proton total cross-section differences in longitudinal and transverse geometries ( $Δ σ_{L}$ and $Δ σ_{T}$ , respectively) between $E_{n} = 5$ and 20 MeV. Single-parameter phase-shift analyses were performed to extract the phase-shift mixing parameter $ɛ_{1}$ , which characterizes the strength of the nucleon-nucleon tensor interaction at low energies. Consistent with the trend of previous determinations at $E_{n} = 25$ and 50 MeV, our values for $ɛ_{1}$ imply a stronger tensor force than predicted by meson-exchange nucleon-nucleon potential models and nucleon-nucleon phase-shift analyses.

Received 17 February 1999

DOI:https://doi.org/10.1103/PhysRevLett.83.2711

Authors & Affiliations

B. W. Raichle^1,4, C. R. Gould^2,4, D. G. Haase^2,4, M. L. Seely^2,4,*, J. R. Walston^2,4,†, W. Tornow^3,4, W. S. Wilburn^3,4,‡, S. I. Penttilä⁵, and G. W. Hoffmann⁶

¹Department of Physical Sciences, Morehead State University, Morehead, Kentucky 40351
²Physics Department, North Carolina State University, Raleigh, North Carolina 27695
³Physics Department, Duke University, Durham, North Carolina 27708
⁴Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708
⁵Los Alamos National Laboratory, Los Alamos, New Mexico 87545
⁶University of Texas, Austin, Texas 78712

^*Present address: Thomas Jefferson National Accelerator Facility, Newport News, VA 23606.
^†Present address: Avanti Corporation, Research Triangle Park, NC 27703.
^‡Present address: Los Alamos National Laboratory, Los Alamos, NM 87545.