Journey to the Center of the Neutron

A neutron contains three quarks, and nuclear physicists don’t completely understand how these move within the particle. Last year, an analysis revealed a negative charge at the center of the neutron, and now an article in the Rapid Communications section of the September Physical Review C attributes this negative core to very fast moving “down” quarks. The results elaborate on an emerging three-dimensional view of these fundamental particles and their proton cousins.