  We report a new measurement of $D^0$-meson production at mid-rapidity
($|y|$\,$<$\,1) in Au+Au collisions at ${\sqrt{s_{\rm NN}} = \rm{200\,GeV}}$
utilizing the Heavy Flavor Tracker, a high resolution silicon detector at the
STAR experiment.
  Invariant yields of $D^0$-mesons with transverse momentum $p_{T}$ $\lesssim
9$\,GeV/$c$ are reported in various centrality bins (0--10\%, 10--20\%,
20--40\%, 40--60\% and 60--80\%). Blast-Wave thermal models are used to fit the
$D^0$-meson $p_{T}$ spectra to study $D^0$ hadron kinetic freeze-out
properties. The average radial flow velocity extracted from the fit is
considerably smaller than that of light hadrons ($\pi,K$ and $p$), but
comparable to that of hadrons containing multiple strange quarks
($\phi,\Xi^-$), indicating that $D^0$ mesons kinetically decouple from the
system earlier than light hadrons. The calculated $D^0$ nuclear modification
factors re-affirm that charm quarks suffer large amount of energy loss in the
medium, similar to those of light quarks for $p_{T}$\,$>$\,4\,GeV/$c$ in
central 0--10\% Au+Au collisions. At low $p_{T}$, the nuclear modification
factors show a characteristic structure qualitatively consistent with the
expectation from model predictions that charm quarks gain sizable collective
motion during the medium evolution. The improved measurements are expected to
offer new constraints to model calculations and help gain further insights into
the hot and dense medium created in these collisions.
