Precision neutron interferometric measurements of the n-p, n-d, and n-3He zero-energy coherent neutron scattering amplitudes

Abstract

We have performed high precision measurements of the zero-energy neutron scattering amplitudes of gas phase molecular hydrogen, deuterium, and ${}^3$He using neutron interferometry. We find $b_{np}=(-3.7384\pm 0.0020)$ fm\cite{Schoen03}, $b_{nd}=(6.6649\pm 0.0040)$ fm\cite{Black03,Schoen03}, and $b_{n^3\text{He}}=(5.8572\pm 0.0072)$ fm\cite{Huffman04}. When combined with the previous world data, properly corrected for small multiple scattering, radiative corrections, and local field effects from the theory of neutron optics and combined by the prescriptions of the Particle Data Group, the zero-energy scattering amplitudes are: $b_{np}=(-3.7389\pm 0.0010)$ fm, $b_{nd}=(6.6683\pm 0.0030)$ fm, and $b_{n^3\text{He}}=(5.853\pm .007)$ fm. The precision of these measurements is now high enough to severely constrain NN few-body models. The n-d and n-${}^3$He coherent neutron scattering amplitudes are both now in disagreement with the best current theories. The new values can be used as input for precision calculations of few body processes. This precision data is sensitive to small effects such as nuclear three-body forces, charge-symmetry breaking in the strong interaction, and residual electromagnetic effects not yet fully included in current models.

arXiv comment6 pages, 4 figures, submitted to Physica B as part of the Festschrift honouring Samuel A. Werner at the International Conference on Neutron Scattering 2005

References in corpus (18)

• An accurate nucleon-nucleon potential with charge-independence breaking
• Effective Field Theory for Few-Nucleon Systems
• A New Expansion for Nucleon-Nucleon Interactions
• Quantum Monte Carlo Calculations of Light Nuclei
• Three-Nucleon Forces from Chiral Effective Field Theory
• Effective Field Theory for Short-Range Forces
• Nucleon-Deuteron Scattering from an Effective Field Theory
• The three- and four-nucleon systems from chiral effective field theory
• Precision neutron interferometric measurements and updated evaluations of the n-p and n-d coherent neutron scattering lengths
• The chiral structure of the Lamb shift and the definition of the proton radius
• Modern nuclear force predictions for the neutron-deuteron scattering lengths
• Hadronic Parity-Violation on the Lattice
• Using chiral perturbation theory to extract the neutron-neutron scattering length from pi- d -> n n gamma
• Precision neutron interferometric measurement of the nd coherent neutron scattering length and consequences for models of three-nucleon forces
• Microscopic calculation of the spin-dependent neutron scattering lengths on 3He
• The spin-dependent nd scattering length - a proposed high-accuracy measurement
• Chiral Perturbation Theory Approach to NN Scattering Problem
• Effective Theory for Neutron-Deuteron Scattering and the Triton

Cited by in corpus (1)

• Noise Refocusing in a Five-blade Neutron Interferometer