Axions to the rescue?

The neutron is, as suggested by its name, electrically neutral. Nevertheless, it still contains electrical charges. More specifically, it is made up of one up quark (charge: 2/3 of an electron charge e) and two down quarks (charge: -1/3 e each). In total, 2/3 + 2*(-1/3) equals exactly 0. But the neutron is not one-dimensional. It has a diameter of at least 1.7 * 10-15 meters, and when three components have to be spread out over any distance, even with an overall zero charge, some difference...