Bay Area scientists investigate possible dark matter signal deep underground

A mile beneath the surface at the Sanford Underground Research Facility in South Dakota, a single unknown particle separated from light, air and cosmic rays collided with the nucleus of a xenon atom, causing electrons to be knocked free in a flash of light — and confounding scientists.

This subatomic interaction captured as part of the LZ Project was so inexplicable that researchers at the Berkeley and Livermore National Laboratories, which both analyzed the data for the experiment, believe the leading explanation is that it was the first recorded observation of dark matter, the mysterious substance that has eluded the greatest minds in physics for over 50 years.

Benjamin Safdi, an award-winning UC Berkeley physicist, said the significance of the discovery could be enormous.