  Disc-halo decomposition on rotationally supported star-forming galaxies
(SFGs) at $z>1$ are often limited to massive galaxies
($M_\star>10^{10}~M_\odot$) and rely on either deep Integral Field Spectroscopy
data or stacking analyses. We present a study of the dark matter (DM) content
of nine $z\approx1$ SFGs selected Using the brightest [OII] emitters in the
deepest Multi-Unit Spectrograph Explorer (MUSE) field to date, namely the 140hr
MUSE Extremely Deep Field, we perform disk-halo decompositions on 9 low-mass
SFGs (with $10^{8.5}<M_\star<10^{10.5}~M_\odot$) using a novel 3D modeling
approach, which together with the exquisite S/N allows us to measure individual
rotation curves to $3\times R_e$. The disk-halo decomposition includes a
stellar, DM, gas, and occasionally a bulge component. The DM component
primarily uses the generalized $\alpha,\beta,\gamma$ profile or a
Navarro-Frenk-White (NFW) profile. The disk stellar masses $M_\star$ obtained
from the [OII] disk-halo decomposition agree with the values inferred from the
spectral energy distributions. While the rotation curves show diverse shapes,
ranging from rising to declining at large radii, the DM fractions within the
half-light radius $f_{\rm DM}(<R_e)$ are found to be 60\% to 95\%, extending to
lower masses (densities) recent results on massive SFGs with
$M_\star>10^{10}~M_\odot$. The DM halos show constant surface densities of
$\sim100~M_\odot$ pc$^{-2}$. Half of the sample shows a strong preference for
cored over cuspy DM profiles. The presence of DM cores appears to be related to
galaxies with stellar-to-halo mass $\log M_\star/M_{\rm vir}\approx-2.5$. In
addition, the cuspiness of the DM profiles is found to be a strong function of
the recent star-formation activity. Both of these results are interpreted as
evidence for feedback-induced core formation in the Cold Dark Matter context.
