LHC@home

The discovery of the Higgs boson at the Large Hadron Collider (LHC) in 2012 illuminated the mechanism of electroweak symmetry breaking, through which the electromagnetic and weak nuclear forces emerge from a unified electroweak force. But if the Higgs discovery answered the question of how electroweak symmetry breaking occurs, it left open the further question of why this breaking occurs at around 250 GeV—an energy that is far removed from other energy scales in particle physics. This energy mismatch goes by the name of the electroweak hierarchy problem, and it is one of the great mysteries in physics. The central question is often reframed in terms of the Higgs mass: why does the Higgs weigh 125GeV∕c2 when a naïve prediction (Fig. 1) would place it 17 orders of magnitude higher, near the Planck mass?