Measurement of np elastic scattering at high energies and very small momentum transfers

Abstract The np elastic differential cross section has been measured for incident neutron momenta 100–400 GeV/ c in the | t | range 6 · 10 −6 − 5 · 10 −1 (GeV/ c ) 2 . The np data of this experiment provide a first direct measurement of the hadronic amplitude for | t | −2 (GeV/ c ) 2 , which is consistent with the extrapolations from higher | t | values. Our data for | t | −4 (GeV/ c ) 2 are consistent with a rise which can be attributed to Schwinger scattering, caused by the interaction of the neutron magnetic moment with the proton.