In July the US Department of Energy and NSF gave the green light to three dark-matter experiments. LZ and SuperCDMS will look for weakly interacting massive particles (WIMPs), and the upgraded Axion Dark Matter Experiment, ADMX-Gen2, will seek a putative dark-matter particle to solve a mystery in the strong force. Funding amounts are being finalized and are subject to congressional appropriations.
More mass—seven metric tons of liquid xenon—and fewer false signals will make the LZ experiment about 300 times as sensitive to traversing WIMPs as its predecessor, LUX (see Physics Today, February 2013, page 19). The WIMP signature in LZ consists of a flash of light from a recoiling xenon nucleus followed by luminescence from drifting electrons. LZ is to be built in the Sanford Underground Research Facility for an estimated $55 million, with help from partners Portugal, Russia, and the UK, and from private sources and the...
