First results on low-mass WIMP from the CDEX-1 experiment at the China
  Jinping underground Laboratory
  The China Dark matter Experiment collaboration reports the first experimental
limit on WIMP dark matter from 14.6 kg-day of data taken with a 994 g p-type
point-contact germanium detector at the China Jinping underground Laboratory
where the rock overburden is more than 2400 m. The energy threshold achieved
was 400 eVee. According to the 14.6 kg-day live data, we placed the limit of N=
1.75 * 10^{-40} cm^{2} at 90% confidence level on the spin-independent
cross-section at WIMP mass of 7 GeV before differentiating bulk signals from
the surface backgrounds.
