  We introduce the minimal momentum subtraction (MiniMOM) scheme for QCD. Its
definition allows the strong coupling to be fixed solely through a
determination of the gluon and ghost propagators. In Landau gauge this scheme
has been implicit in the early studies of these propagators, especially in
relation to their non-perturbative behaviour in the infrared and the associated
infrared fixed-point. Here we concentrate on its perturbative use. We give the
explicit perturbative definition of the scheme and the relation of its
beta-function and running coupling to the MSbar scheme up to 4-loop order in
general covariant gauges. We also demonstrate, by considering a selection of
N_f=3 examples, that the apparent convergence of the relevant perturbative
series can in some (though not all) cases be significantly improved by
re-expanding the MSbar coupling version of this series in terms of the MiniMOM
coupling, making the MiniMOM coupling also of potential interest in certain
phenomenological applications.
