Final word is near on dark-matter signal

Viewed end on, the arrays of photomulti­plier tubes on the Large Underground Xenon (LUX) experiment look like beds of flowers. The hope is that they will capture sparks of light emitted when particles of dark matter collide with liquid xenon.With 122 detector tubes, LUX is much more sensitive than its closest rival in the competitive field of dark-matter searches — and in just days, physicists the world over will know whether that advantage has yielded definitive results.

The project, based at the Sanford Underground Research Facility in Lead, South Dakota, will release its first findings on 30 October. They are likely to reveal whether tentative dark-matter signals seen by other experiments are real, and will also inform ongoing discussions about how much more time and money should be spent on the hunt for dark matter. “The potential is there, and all the community is waiting with bated breath to see what they observe,” says Juan Collar, a physicist who leads a rival experiment at the University of Chicago in Illinois.