'The Majoron' — a bizarre particle that's its own opposite — could explain the biggest mysteries...

A hidden family of "ghost particles" may be responsible for all the dark matter in the universe — and the reason that there is any matter at all, a recent preprint study suggests.

One of the most puzzling questions in modern cosmology is why the universe is filled with matter in the first place. The problem is that almost all fundamental particle reactions produce exact numbers of matter and antimatter particles, which then go on to annihilate each other in flashes of energy. But the universe has an abundance of matter and very little antimatter. So why didn't everything just disappear in the early universe?

The problem is known as baryogenesis, and the leading hypothesis is that some unknown process led to an imbalance of matter over antimatter in the first moments of the Big Bang. But what could that process have been?