title: Precision neutron interferometric measurement of the nd coherent neutron scattering length and consequences for models of three-nucleon forces.
abstract: We have performed the first high precision measurement of the coherent neutron scattering length of deuterium in a pure sample using neutron interferometry. We find b(nd)=(6.665+/-0.004) fm in agreement with the world average of previous measurements using different techniques, b(nd)=(6.6730+/-0.0045) fm. We compare the new world average for the nd coherent scattering length b(nd)=(6.669+/-0.003) fm to calculations of the doublet and quartet scattering lengths from several modern nucleon-nucleon potential models with three-nucleon force (3NF) additions and show that almost all theories are in serious disagreement with experiment. This comparison is a more stringent test of the models than past comparisons with the less precisely determined doublet scattering length of (2)a(nd)=(0.65+/-0.04) fm.
authors.affiliation: University of North Carolina at Wilmington, Wilmington, North Carolina 28403-3297, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Black
authors.forename: P R
authors.initials: PR
authors.lastname: Huffman
authors.forename: D L
authors.initials: DL
authors.lastname: Jacobson
authors.forename: W M
authors.initials: WM
authors.lastname: Snow
authors.forename: K
authors.initials: K
authors.lastname: Schoen
authors.forename: M
authors.initials: M
authors.lastname: Arif
authors.forename: H
authors.initials: H
authors.lastname: Kaiser
authors.forename: S K
authors.initials: SK
authors.lastname: Lamoreaux
authors.forename: S A
authors.initials: SA
authors.lastname: Werner