New measurement yields smaller proton radius

Using the first new method in half a century for measuring the size of the proton via electron scattering, the PRad collaboration has produced a new value for the proton's radius in an experiment conducted at the Department ...

Physicists team up to tackle proton radius problem

Ten years ago, just about any nuclear physicist could tell you the approximate size of the proton. But that changed in 2010, when atomic physicists unveiled a new method that promised a more precise measurement. The new quantity ...

Proton radius puzzle may be solved by quantum gravity

(Phys.org) —Officially, the radius of a proton is 0.88 ± 0.01 femtometers (fm, or 10-15 m). Researchers attained that value using two methods: first, by measuring the proton's energy levels using hydrogen spectroscopy, ...

Physicists confirm surprisingly small proton radius

International team of physicists confirms surprisingly small proton radius with laser spectroscopy of exotic hydrogen. The initial results puzzled the world three years ago: the size of the proton (to be precise, its charge ...