Radiative neutron capture near threshold

The surprisingly large 'pair' term corrections to threshold radiative neutron capture, previously calculated by Riska and Brown, and Gari and Huffman, are calculated in a new way in which they appear as relativistic corrections to the impulse approximation arising from the small negative energy components of the wave functions of the two nucleon system. Looking at these corrections from this point of view suggests not only that these small negative energy components are observable in non-relativistic processes, but also that the size of these corrections may ultimately depend on, or give information about, a consistent relativistic treatment of the nuclear force problem. (Auth.)