An effective field theory calculation of the parity violating asymmetry in(n)over-right-arrow+p -> d+gamma

Weak interactions are expected to induce a parity violating pion-nucleon co upling, h(pi-NN)((1)). This coupling should be measurable in a proposed exp eriment to study the parity violating asymmetry A(gamma) in the process (n) over-right-arrow + p --> d + gamma, We compute the leading dependence of A( gamma) on the coupling h(pi-NN)((1)) using recently developed effective fie ld theory techniques and find an asymmetry of A(gamma) = +0.17 h(pi-NN)((1) ) at leading order. This asymmetry has the opposite sign to that given by D esplanques and Missimer. (C) 1999 Published by Elsevier Science B.V. All ri ghts reserved.