This paper investigates disentanglement as a result of evolution according to
a class of master equations which include dissipation and interparticle
interactions. Generalizing an earlier result of Di\'{o}si, the time taken for
complete disentanglement is calculated (i.e. for disentanglement from any other
system). The dynamics of two harmonically coupled oscillators is solved in
order to study the competing effects of environmental noise and interparticle
coupling on disentanglement. An argument based on separability conditions for
gaussian states is used to arrive at a set of conditions on the couplings
sufficient for all initial states to disentangle for good after a finite time.Comment: Paper in conjunction with and following on from P.J. Dodd and J.J.
Halliwell: quant-ph/031206