Effective field theory approach to (n)over-right-arrow+(p)over-right-arrow-> d+gamma at threshold

Previously, in an effective field theory formulated by us, we have carried out parameter-free calculations of a large number of low-energy two-nucleon properties. An experiment at the Institut Laue-Langevin is currently measu ring spin-dependent effects in the polarized np capture process (n) over ri ght arrow + (p) over right arrow --> d + gamma at threshold. Noting that sp in-dependent observables for this reaction are sensitive to terms of chiral orders higher than hitherto studied, we extend our effective theory approa ch to this process and describe how to make parameter-free predictions on t he spin-dependent observables. (C) 2000 Published by Elsevier Science B.V. All rights reserved.