CERN Detects Evidence of Ultra-Rare B-Meson Decay: Standard Model, Muons and New Physics Explained for UPSC 2026
CERN's LHCb experiment announced evidence of the extremely rare decay of a neutral B meson into a muon–antimuon pair on 3 November 2026. The phenomenon occurs at roughly one in ten billion decays, and the combined analysis reached a significance of 3.2 sigma, below the 5-sigma benchmark used for a discovery. The result agrees with Standard Model predictions and places tighter constraints on possible new physics. This Civil Service Gurukul article explains mesons, quarks, leptons, muons, weak interactions, branching fractions, the Large Hadron Collider, statistical significance and the difference between evidence and discovery. It also examines India's particle-physics research ecosystem and includes UPSC Prelims MCQs and a GS-III Mains model answer.
