An international team of scientists confirms a surprisingly small proton radius with laser spectroscopy of exotic hydrogen. An international team of scientists confirms a surprisingly small proton ...

Big problems sometimes come in small packages. The problem with which physicists must now concern themselves measures a mere 0.0350 millionth of a millionth of a millimetre. This is precisely the ...

The PRad physics experiment studies how electrons scatter off of protons A scientific tug-of-war is underway over the size of the proton. Scientists can’t agree on how big the subatomic particle is, ...

A puzzle at the heart of the atom refuses to go away. The most precise measurement yet of the proton’s radius confirms that it sometimes seems smaller than the laws of physics demand – an issue that ...