Neutron Decay May Hint at Dark Matter

Neutrons decay within about 14.5 min, but their exact lifetime is still debated, as two types of neutron decay experiments give conflicting results. The source for this discrepancy could be some unidentified systematic error. But another possibility is that neutrons decay into invisible particles that constitute the missing dark matter. This new hypothesis has sparked significant interest, with one group of experimenters already putting the idea to the test. The results of that effort constrain one version of the theory, but other scenarios remain viable.