Neutron-proton analyzing power at 12 MeV and inconsistencies in parametrizations of nucleon-nucleon data

Braun, R.T. ; Tornow, W. ; Howell, C.R. ; et al.
Phys.Lett.B 660 (2008) 161-166, 2008.
Inspire Record 778429 DOI 10.17182/hepdata.50912

We present the most accurate and complete data set for the analyzing power Ay(theta) in neutron-proton scattering. The experimental data were corrected for the effects of multiple scattering, both in the center detector and in the neutron detectors. The final data at En = 12.0 MeV deviate considerably from the predictions of nucleon-nucleon phase-shift analyses and potential models. The impact of the new data on the value of the charged pion-nucleon coupling constant is discussed in a model study.

1 data table

The measured analysing power at 12 MeV. Errors contain statistics and systematics added in quadrature.


Neutron-proton analyzing power data between 7.6 and 18.5 MeV

Weisel, G.J. ; Tornow, W. ; Howell, C.R. ; et al.
Phys.Rev.C 46 (1992) 1599-1606, 1992.
Inspire Record 351665 DOI 10.17182/hepdata.26047

Measurements of the analyzing power Ay(θ) for neutron-proton scattering have been performed at 7.6, 12.0, 14.1, 16.0, and 18.5 MeV. The experimental setup is described as are the finite-geometry corrections applied to the data. One of these corrections, due to the presence of carbon in the scintillators used for neutron detection, is discussed in detail. The Ay(θ) data are compared to the predictions of the Paris and Bonn nucleon-nucleon potentials and the predictions of two phase-shift analyses, one of which incorporates charge-independence breaking effects in the 3P waves.

5 data tables

Measured analyzing power at 7.6 MeV.

Measured analyzing power at 12.0 MeV.

Measured analyzing power at 14.1 MeV.

More…