Scientists Intrigued by a Surprising Result in the Search for Dark Matter

Dark matter is the invisible stuff that accounts for roughly 85% of the mass in the universe, and for decades, physicists have been trying to figure out what it's made of. Now an experimental facility located nearly a mile below ground in South Dakota has recorded a single interaction between subatomic particles that doesn't match what's expected from normal matter. Has a dark-matter particle been detected at last? It's too early to say, but the anomaly is definitely attracting a...