The LHCb Collaboration's four-standard-deviation departure from Standard Model predictions in B-meson rare decays remains intact at 8.4 inverse femtobarns of integrated luminosity, three times the 2018 reference dataset on which the original anomaly was established. [1] The decay channels under study sit in the electroweak-penguin family — including the so-called "charming penguin" loop diagrams whose hadronic uncertainties were the leading skeptical explanation for the discrepancy. Those uncertainties, with three times the data, have not absorbed the signal.

The Sunday paper read the persistence at 8.4 fb⁻¹ as the moment the hadronic-uncertainty defense gets harder to sustain. The deeper reading is the arithmetic of discovery. Four sigma places the probability of statistical fluctuation at roughly one in sixteen thousand. The five-sigma threshold the particle-physics field uses for "discovery" sits at one in 3.5 million. The remaining gap is a luminosity question. Run 3 will continue through year-end; the High-Luminosity LHC upgrades that begin physics-grade recording in the early 2030s will deliver roughly fifteen times more data than Run 3 is on track to. [2]

The structural reading is the slow-physics one. The federal-science thread the paper has tracked this spring is an executive-action register operating on weekly cycles; B-meson rare decays operate on the multi-year arithmetic the HL-LHC upgrade was designed to. The candidate explanations Quanta and CERN Courier have catalogued — Z-prime gauge bosons, a class of leptoquark particles — remain the leading new-physics frames, and neither has been independently observed. [3]

What is real today is that the Standard Model's predictions for a class of B-meson rare decays do not match LHCb's measurements, and the gap has not closed.

-- KENJI NAKAMURA, Tokyo