Collaborative Research: R&D Towards Higher Sensitivity Directional Dark Matter Detectors

Colorado State University, Fort Collins CO

Investigators

Abstract

In this era of precision cosmology, measurements suggest that ordinary matter represents only a fraction of the total matter density in the Universe. The rest, whose presence we only infer gravitationally, is unknown in its nature, and is termed dark matter. Particle physics suggests that dark matter comprises relic Weakly Interacting Massive Particles (WIMPs) left over from the Big Bang. Experimental efforts to directly detect WIMPs are extremely challenging due to small interaction probabilities and large backgrounds. The motion of the Earth through the galaxy produces a head-wind of WIMPs. The angular distribution of recoils from WIMP interactions has a ~100% asymmetry, and is modulated at the sidereal rate on account of the Earth's rotation. No known background can mimic this signal. The practical implications of the technology being developed for such searches have promising applications to low background alpha and neutron measurements. This work also includes the training of a diverse set of undergraduates and graduate students in increasingly rare small-scale experiments, giving them exposure to a wide range of research experience. The Directional Recoil Identification From Tracks (DRIFT) experiment leads the field of directional dark matter detection. The intellectual merit of this award resides in DRIFT's sensitivity to this modulated signature, which provides a unique window into one of the most important questions in science today. NSF-funded DRIFT-IId work over the last several years has led to enormous experimental progress. The collaboration is in the final stages of commissioning a new DRIFT-IIe detector. The operation of both detectors will test the viability of long-duration background-free exposures. This award will provide funding to continue the operations of DRIFT-II.