New Limits on Interactions between Weakly Interacting Massive Particles
  and Nucleons Obtained with CsI(Tl) Crystal Detectors
  New limits are presented on the cross section for Weakly Interacting Massive
Particle (WIMP) nucleon scattering in the KIMS CsI(T) detector array at the
Yangyang Underground Laboratory. The exposure used for these results is 24524.3
kg\cdotdays. Nuclei recoiling from WIMP interactions are identified by a pulse
shape discrimination method. A low energy background due to alpha emitters on
the crystal surfaces is identified and taken into account in the analysis. The
detected numbers of nuclear recoils are consistent with zero and 90% confidence
level upper limits on the WIMP interaction rates are set for electron
equivalent energies from 3 keV to 11 keV. The 90% upper limit of NR event rate
for 3.6-5.8 keV corresponding to 2-4 keV in NaI(T) is 0.0098 counts/kg/keV/day
which is below the annual modulation amplitude reported by DAMA. This is
incompatible with interpretations that enhance the modulation amplitude such as
inelastic dark matter models. We establish the most stringent cross section
limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses
greater than 20 GeV/c2.
