CERN physicists have delivered the most accurate measurement of the Higgs boson's lifetime to date, employing an innovative indirect technique.
Proposed by physicist Peter Higgs in the mid-1960s, the Higgs boson—named after him—was confirmed in 2012 at CERN. Elementary particles like the Higgs are the fundamental building blocks of matter, beyond which you can't break them down further. The Higgs exists as part of a pervasive field that fills the entire universe.
Picture a uniform blanket of snow covering the cosmos, with the Higgs boson as the individual snowflake. A fast-moving skier—say, a photon carrying light—zips across without sinking, leaving no trace and acquiring no mass. Slower particles interact more with the Higgs field, sinking deeper and gaining mass accordingly.
In essence, the Higgs boson forms the Higgs field, which imparts mass to other particles through interactions. Without it, matter as we know it wouldn't exist. Its 2012 discovery ranks among the century's greatest scientific milestones.
Since 2012, the Large Hadron Collider (LHC) has produced Higgs bosons routinely, enabling detailed study. Yet its fleeting lifetime—around seven-millionths of a second—poses challenges, as it decays almost instantly into other particles. Direct lifetime measurements remain particularly tricky.
CERN researchers turned to an indirect approach, analyzing the particle's mass width—the spread of possible masses. Per quantum mechanics, a wider mass width correlates with a shorter lifetime, allowing precise calculation.
The Higgs boson's nominal mass is 125 gigaelectronvolts (GeV). Heisenberg's uncertainty principle permits rare productions at higher masses.
By comparing Higgs bosons near the nominal mass to those with significantly higher masses, the team determined a lifetime of 210 yoctoseconds—roughly 10^{-22} seconds (a decimal point followed by 22 zeros).
With an uncertainty of (+2.3/-0.9) × 10^{-22} seconds, this is the most precise Higgs lifetime measurement yet, advancing our understanding of this cornerstone particle.
