  We report the discovery of a sub-Jovian-mass planet, OGLE-2014-BLG-0319Lb.
The characteristics of this planet will be added into a future extended
statistical analysis of the Microlensing Observations in Astrophysics (MOA)
collaboration. The planetary anomaly of the light curve is characterized by MOA
and OGLE survey observations and results in three degenerate models with
different planetary mass-ratios of $q=(10.3,6.6,4.5)\times10^{-4}$,
respectively. We find that the last two models require unreasonably small
lens-source relative proper motions of $\mu_{\rm rel}\sim1\;{\rm mas/yr}$.
Considering Galactic prior probabilities, we rule out these two models from the
final result. We conduct a Bayesian analysis to estimate physical properties of
the lens system using a Galactic model and find that the lens system is
composed of a $0.49^{+0.35}_{-0.27}\;M_{\rm Jup}$ sub-Jovian planet orbiting a
$0.47^{+0.33}_{-0.25}\; M_{\odot}$ M-dwarf near the Galactic bulge. This
analysis demonstrates that Galactic priors are useful to resolve this type of
model degeneracy. This is important for estimating the mass ratio function
statistically. However, this method would be unlikely successful in shorter
timescale events, which are mostly due to low-mass objects, like brown dwarfs
or free-floating planets. Therefore, careful treatment is needed for estimating
the mass ratio function of the companions around such low-mass hosts which only
the microlensing can probe.
