Direct Dark Matter searches with the LUX and LZ experiments

Astronomy Unit Seminars
Chamkaur Ghag
Karim Malik
November 27th, 2015 at 14:30
GO Jones Room 610

Discovery of the nature of dark matter is internationally recognised as one of the greatest contemporary challenges in science, fundamental to our understanding of the Universe. Weakly Interacting Massive Particles (WIMPs) that arise naturally in several models of physics beyond the Standard Model are compelling candidates for the dark matter. The discovery of galactic WIMPs would therefore enlighten two of the outstanding problems of modern physics - the matter composition of the Universe and the extrapolation of the Standard Model of particle physics to GUT scales. I will present on the current status in the worldwide hunt for WIMPs, and focus on the LXe TPC based LUX experiment, operated in the Davis Cavern of the SURF laboratory, USA, that announced results from it's first science run. From an exposure of 85 days, having found no evidence of signal above expected background, LUX has set constraints on scalar WIMP-nucleon interactions above 7.6x10-46 cm2 at 33 GeV/c2 WIMP mass (90% C.L.) - three times more sensitive than any competing experiment. This first result also seriously challenges the interpretation of hints of signal detected in other experiments as arising from low-mass WIMPs. Finally, I will report on the multi-tonne successor to LUX: the LZ experiment. This instrument will have sensitivity ideally matched to explore the bulk of the remaining theoretically favoured electroweak phase space towards galactic Dark Matter discovery.