We present a detailed comparison of simulations of disordered melts of symmetric AB
diblock copolymers to predictions of the renormalized one-loop (ROL) theory. The behaviors
of the structure factor S (q) and of single-chain correlations are studied over a range of chain
lengths (N= 16,..., 128) for two models: one with harshly repulsive pair interactions and
another with very soft interactions. The ROL theory is shown to provide an excellent
description of the dependence of S (q) on chain length and thermodynamic conditions for …