The chiral extrapolation of the vector meson mass calculated in
partially-quenched lattice simulations is investigated. The leading one-loop
corrections to the vector meson mass are derived for partially-quenched QCD. A
large sample of lattice results from the CP-PACS Collaboration is analysed,
with explicit corrections for finite lattice spacing artifacts. To incorporate
the effect of the opening decay channel as the chiral limit is approached, the
extrapolation is studied using a necessary phenomenological extension of chiral
effective field theory. This chiral analysis also provides a quantitative
estimate of the leading finite volume corrections. It is found that the
discretisation, finite-volume and partial quenching effects can all be very
well described in this framework, producing an extrapolated value of M_\rho in
excellent agreement with experiment. This procedure is also compared with
extrapolations based on polynomial forms, where the results are much less
enlightening.Comment: 30 pages, 13 fig