In the eleven years since its discovery, studies of the Higgs boson have become a central avenue for shedding light on the fundamental structure of the Universe. Precise measurements of Higgs-boson properties are among the most powerful tools physicists have to put pressure on the Standard Model — and now, it’s the turn of the Higgs-boson mass. Candidate Higgs boson decays into two photons in the ATLAS experiment. Image credit: CERN. The mass...