SPIN CORRELATION AND ANALYZING POWER MEASUREMENTS FOR NEUTRON-PROTON RADIATIVE-CAPTURE AT T(N) = 183 MEV

We have measured the spin correlation coefficient (C(NN)) and the neut ron and proton analyzing powers (A(n) and A(p)) for the np over arrow pointing right --> dgamma reaction at a neutron beam energy of 183 MeV . Calculations of the spin correlation are particularly sensitive to t he treatment of mesonic and isobaric currents. Predictions that includ e both explicit photon couplings to exchanged mesons and intermediate isobar states, and relativistic correction terms in the Hamiltonian, a gree well with our data, thus demonstrating the quantitative accuracy of present treatments of meson-exchange currents at moderate momentum transfer (q is similar to 1-2 fm-1).