  The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a
systematic study of $K_S^0$ and $K^{*0}$ meson production at midrapidity in
$p$$+$$p$, $d$$+$Au, and Cu$+$Cu collisions at $\sqrt{s_{_{NN}}}=200$ GeV. The
$K_S^0$ and $K^{*0}$ mesons are reconstructed via their $K_S^0 \rightarrow
\pi^0(\rightarrow \gamma\gamma)\pi^0(\rightarrow\gamma\gamma)$ and $K^{*0}
\rightarrow K^{\pm}\pi^{\mp}$ decay modes, respectively. The measured
transverse-momentum spectra are used to determine the nuclear modification
factor of $K_S^0$ and $K^{*0}$ mesons in $d$$+$Au and Cu$+$Cu collisions at
different centralities. In the $d$$+$Au collisions, the nuclear modification
factor of $K_S^0$ and $K^{*0}$ mesons is almost constant as a function of
transverse momentum and is consistent with unity showing that
cold-nuclear-matter effects do not play a significant role in the measured
kinematic range. In Cu$+$Cu collisions, within the uncertainties no nuclear
modification is registered in peripheral collisions. In central collisions,
both mesons show suppression relative to the expectations from the $p$$+$$p$
yield scaled by the number of binary nucleon-nucleon collisions in the Cu$+$Cu
system. In the $p_T$ range 2--5 GeV/$c$, the strange mesons ($K_S^0$, $K^{*0}$)
similarly to the $\phi$ meson with hidden strangeness, show an intermediate
suppression between the more suppressed light quark mesons ($\pi^0$) and the
nonsuppressed baryons ($p$, $\bar{p}$). At higher transverse momentum, $p_T>5$
GeV/$c$, production of all particles is similarly suppressed by a factor of
$\approx$ 2.
