Friday, April 17, 2020
Neutrinos could shed light on why the Universe has so much more matter than antimatter
A major finding in particle physics reminds us of the importance of robust preliminary results — and paves the way for more exciting discoveries.
Nuclear-weapons physicists Clyde Cowan and Frederick Reines considered the neutrino “the smallest bit of material reality ever conceived of by man” [sic].
That was in a commentary1 for Nature in 1956, published a few months after they published a paper in Science2 reporting the experimental discovery of neutrinos. These subatomic particles lack an electrical charge and are extremely hard to detect, because they have very little interaction with other forms of matter. The pair wondered about the relationship between neutrinos and their counterparts, antineutrinos. With the benefit of hindsight, that turned out to be a rather important question.
In this week’s Nature, researchers — directly following in the footsteps of Cowan and Reines — suggest that differences between neutrinos and antineutrinos might help to explain one of the Universe’s biggest mysteries.