  The predictions of Drell-Yan production of low-mass, lepton-pairs, at high
rapidity at the LHC, are known to depend sensitively on the choice of
factorization and renormalization scales. We show how this sensitivity can be
greatly reduced by fixing the factorization scale of the LO contribution based
on the known NLO matrix element, so that observations of this process at the
LHC can make direct measurements of parton distribution functions in the low x
domain; x less than about 10^{-4}.
