LHCb Finds 3.2-Sigma Evidence of B d Meson Decay Into 2 Muons
Updated
Updated · ScienceAlert · Nov 6
LHCb Finds 3.2-Sigma Evidence of B d Meson Decay Into 2 Muons
3 articles · Updated · ScienceAlert · Nov 6
Summary
CERN’s LHCb collaboration reported evidence that a B d meson decays into a muon and an anti-muon, a process expected only about once in 10 billion decays.
The result reaches 3.2 sigma—above the 3-sigma evidence threshold but short of the 5-sigma discovery standard—using 2024-2025 data combined with measurements from 2011-2018.
A recent LHCb upgrade and machine-learning analysis sharpened the signal enough to isolate the decay, which researchers have pursued since the 1980s.
The measurement matches Standard Model expectations, tightening constraints on possible new particles or forces at scales beyond the LHC’s direct reach.
Further collider upgrades planned for the 2030s are expected to raise collision and data rates by roughly an order of magnitude, helping confirm the decay and probe rarer effects.