Dark Matter Detector Receives Green Light

Construction on a next-generation dark matter detector to be built nearly a mile underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, was given the go-ahead at the beginning of last month. The LUX-ZEPLIN (LZ) experiment, swill try to determine whether theorised dark matter particles known as WIMPs (weakly interacting massive particles) actually exist.

The LZ collaboration now has about 220 participating scientists and engineers who represent 38 institutions around the globe – with UK scientists, supported by the Science and Technology Facilities Council, representing about a quarter of the collaboration.

Henrique Araújo, from Imperial College London, said: “We are looking forward to seeing everything come together after a long period of design and planning.”

The nature of dark matter, which physicists describe as the invisible component or ‘missing mass’ in the universe, has eluded scientists since its existence was deduced by Swiss astronomer Fritz Zwicky in 1933. The quest to find out what dark matter is made of, or whether it can be explained by tweaking the known laws of physics, is considered one of the most pressing questions in particle physics.

It is estimated that LZ will be at least 50 times more sensitive to finding signals from dark matter particles than its predecessor, the Large Underground Xenon experiment (LUX).

The fast-moving schedule for LZ will help it stay competitive with similar international dark matter detection experiments, the XENON1T experiment at Italy's Gran Sasso National Laboratory and China's PandaX-II. Both of these projects have a similar schedule and scale to LZ, though LZ participants are aiming to achieve a higher sensitivity to dark matter than the other contenders.

“The science is highly compelling, so it’s being pursued by physicists all over the world,” said Carter Hall, the spokesperson for the LZ collaboration and an associate professor of physics at the University of Maryland. “It's a friendly and healthy competition, with a major discovery possibly at stake.”

Onsite assembly and installation will begin in 2018 with completion expected in 2020.