Search for Light Dark Matter in XENON10 Data

We report results of a search for light (less than or similar to 10 GeV) particle dark matter with the XENON10 detector. The event trigger was sensitive to a single electron, with the analysis threshold of 5 electrons corresponding to 1.4 keV nuclear recoil energy. Considering spin-independent dark matter-nucleon scattering, we exclude cross sections sigma(n) > 7 x 10(-42) cm(2), for a dark matter particle mass m(chi) = 7 GeV. We find that our data strongly constrain recent elastic dark matter interpretations of excess low-energy events observed by CoGeNT and CRESST-II, as well as the DAMA annual modulation signal.