Dark matter particles may come from decaying neutrons

Scientists measuring the lifetime of neutrons believe that the remaining particles could be dark matter.
By Lliane Hunter | May 24, 2018
Physicists studying decaying neutrons believe that the death of these particles may be a source of dark matter in the universe. By probing the lifetime of neutrons, researchers now suggest that about 1 percent of the time that neutrons decayalong with breaking down into a few known particlesalso produce dark matter particles, writes Charles Q. Choi for Space.com.

There are two different ways to measure the lifetime of neutrons. In the experiment that some believe produces dark matter particles, researchers place ultracold neutrons in a bottle and see how many are left after a certain amount of time. "It would be truly amazing if the good old neutron turned out to be the particle enabling us to probe the dark matter sector of the universe," says Bartosz Fornal, a theoretical physicist at the University of California. Fornal and Benjamin Grinstein conducted the bottle experiment and explored different scenarios of "dark decay" for neutrons, where neutrons break down into both dark matter particles and ordinary components such as gamma rays or electrons.

Grinstein explains that their proposed new particles are "dark in that, like dark matter, they interact feebly with normal matter." Theoretical physicist Jessie Shelton, studying neutron decay in neutron stars, notes that if neutrons indeed decay into dark matter, they will not give rise to just one kind of particle, but at least two. However, as researchers continue to study exotic neutron dark decays, future experiments may prove that this anomaly has nothing to do with dark matter at all.


We are dedicated to maintaining a respectful community that actively engages in lively discussions about news stories and blog posts. Please keep the following in mind when writing your comments.