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A Precision Measurement of the Neutron Scattering Length of4He Using Neutron Interferometry
Published
Author(s)
Robert W. Haun, Fred Wietfeldt, Muhammad D. Arif, Michael G. Huber, T C. Black, Ben Heacock, Dmitry Pushin, Chandra B. Shahi
Abstract
We report a 0.08% measurement of the bound neutron scattering length of 4He using neutron interferometry. The result is b=(3.0982 ± 0.0021[stat] ± 0.0014[syst]) fm. The corresponding free atomic scattering length is a=(2.4746 ± 0.0017[stat] ± 0.0011[syst]) fm. With this result the world average becomes b=(3.0993±0.0025) fm, a 2% downward shift and a reduction in uncertainty by more than a factor of six. Our result is in disagreement with a previous neutron interferometric measurement but is in good agreement with earlier measurements using neutron transmission.
Haun, R.
, Wietfeldt, F.
, Arif, M.
, Huber, M.
, Black, T.
, Heacock, B.
, Pushin, D.
and Shahi, C.
(2020),
A Precision Measurement of the Neutron Scattering Length of4He Using Neutron Interferometry, Physics Review Letters, [online], https://doi.org/10.1103/PhysRevLett.124.012501, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929140
(Accessed October 10, 2025)