A direct dark matter search in XMASS-I
  A search for dark matter using an underground single-phase liquid xenon
detector was conducted at the Kamioka Observatory in Japan, particularly for
Weakly Interacting Massive Particles (WIMPs). We have used 705.9 live days of
data in a fiducial volume containing 97 kg of liquid xenon at the center of the
detector. The event rate in the fiducial volume after the data reduction was
${\rm (4.2 \pm 0.2) \times 10^{-3} \, day^{-1}kg^{-1} keV_{ee}^{-1}}$ at ${\rm
5 \, keV_{ee}}$, with a signal efficiency of ${\rm 20\%}$. All the remaining
events are consistent with our background evaluation, mostly of the
"mis-reconstructed events" originated from $^{210}$Pb in the copper plates
lining the detector's inner surface. The obtained upper limit on a
spin-independent WIMP-nucleon cross section was ${\rm 2.2 \times 10^{-44} \,
cm^{2}}$ for a WIMP mass of ${\rm 60 \, GeV/c^{2}}$ at the $90\%$ confidence
level, which was the most stringent limit among results from single-phase
liquid xenon detectors.
