<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>np</mml:mi></mml:math>scattering measurements at 96 MeV

Abstract

The differential $\mathrm{np}$ scattering cross section has been measured at 96 MeV in the angular range ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}=74--180\ifmmode^\circ\else\textdegree\fi{}$ at the neutron beam facility of the The Svedberg Laboratory in Uppsala. A subset of the data, covering $116--180\ifmmode^\circ\else\textdegree\fi{},$ has previously been published. The new, extended angular distribution has been normalized to the experimental total $\mathrm{np}$ cross section. Between 150\ifmmode^\circ\else\textdegree\fi{} and $180\ifmmode^\circ\else\textdegree\fi{},$ the angular distribution is steeper than for most previous measurements and nucleon-nucleon potential predictions. At $180\ifmmode^\circ\else\textdegree\fi{},$ the difference amounts to about 10%, implying serious consequences because of the fundamental importance of this cross section. A value of the charged $\ensuremath{\pi}\mathrm{NN}$ coupling constant consistent with our earlier result at 162 MeV has been extracted from the data.