This award addresses the question of the nature of Dark Matter (DM) in the Universe with an experimental direct detection search for Weakly Interactive Massive Particles (WIMPs) using two-phase xenon detectors within the XENON program. This Collaboration is currently at the 100 kg mass scale with the XENON100 experiment at the Gran Sasso Underground Laboratory (LNGS), Italy. The next phase will be a detector at the ton scale (XENON1T) with a sensitivity goal of more than two orders of magnitude better than the current best limits from XENON100, currently the lowest background and largest mass direct detection experiment operating underground.
These funds will enable these groups to continue the XENON100 experiment to reach the design sensitivity for the spin-independent cross-section and to study other WIMP interaction scenarios. They plan to take data for at least one continuous year throughout 2011 to search for both spin-independent and spin-dependent DM, for inelastic DM and low mass DM and for an annual modulation signal in the XENON100 data.
Broader Impacts: The XENON science, addressing questions about fundamental properties of the Universe, has all the ingredients to captivate the interest and imagination of students and the general public alike. Technical-related work can impact society in a number of ways: liquid xenon imaging detectors and related technologies find applications in several fields outside particle astrophysics, including national security and medical imaging research.