This is the most precise look yet at the fine-structure constant
An ultraprecise new measurement has given some weird particle physics theories a black eye.
By measuring one of nature’s most fundamental constants more precisely than before, scientists have tested proposed tweaks to the standard model, the theory governing fundamental particles. The result, reported April 13 in Science, casts doubt on hypothetical particles called dark photons and other potential oddities.
The quantity in question is the fine-structure constant, a number that governs the strength of electromagnetic interactions (SN: 11/12/16, p. 24), such as those that confine electrons within atoms. Previously, the most precise measurement of the constant was indirect, relying on a measurement of the electron’s magnetic properties and using complex theoretical calculations to infer the constant’s value.
Now, physicist Holger Müller