Carnegie Mellon University's Professor Curtis Meyer and his research colleagues explore an uncharted world inside protons and neutrons ... known as a hybrid meson in a journal paper published ...

He called it a neutron, and imagined it as a paired proton and electron. There was no evidence for any of these ideas. Chadwick kept the problem in the back of his mind while working on other things.

Occasionally, and purely by chance, some of these neutrons collide with the nuclei of some of the nitrogen atoms. The nucleus of each nitrogen atom contains seven protons and seven neutrons.

In the world of nuclear physics, protons often take the spotlight. But now, for the first time, the neutron has stepped into it. A recent experiment using the U.S. Department of Energy’s ...