Collaborative Proposal: Continuation of th XENON Dark Matter Project: Construction and Underground Operation of an Upgraded XENON100 Detector

William Marsh Rice University, Houston TX

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project addresses the question of the nature of dark matter in the Universe with an experimental search for Weakly Interactive Massive Particles (WIMPs) using two-phase xenon detectors. This group is currently operating at the 100 kg mass scale with the XENON100 experiment which has replaced the XENON10 prototype in the same shield and location at the Gran Sasso Underground Laboratory. The worldwide race towards direct dark matter detection has been dramatically accelerated by the fast evolution of detectors based on noble liquids. They have shifted the scale of target mass from a few to tens of kilograms, while reducing the overall gamma/beta background to less than 0.001 events/kg/keV/day, much lower than scintillator and cryogenic bolometer detectors. Despite being only a prototype, XENON10 has shown the potential of two-phase Xe detectors for dark matter searches, bringing the XENON program to the forefront of the field. This award will provide funds to continue the XENON program for 2 more years to complete the dark matter search with the current XENON100 detector within 2009, and to realize an upgraded detector by early 2010 in the same shield and location. Additionally, XENON100 has a robust possibility to address questions related to the DAMA/LIBRA annual modulation signature, shedding new light on this controversial result. The broader impact of the XENON science program addresses questions about the fundamental properties of the Universe and 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.