The LHCb Collaboration's persistent four-standard-deviation departure from Standard Model predictions in B-meson rare decays remains intact as the experiment's Run 3 dataset crosses 8.4 inverse femtobarns of integrated luminosity, three times the 2018 sample on which the original anomaly was first established. The decay channels under study, including B0 → K*0μ+μ−, sit in the electroweak penguin family — among them the so-called "charming penguin" loop diagrams whose hadronic uncertainties were the leading skeptical explanation for the discrepancy. Those uncertainties, with the larger dataset, have not absorbed the signal. [1]

The structural reading is the one that matters. Four sigma is the threshold above which the probability of statistical fluctuation falls to roughly one in sixteen thousand. The five-sigma threshold the particle-physics community uses for "discovery" sits at one in 3.5 million. The remaining gap is a luminosity question; the LHCb experiment has, since 2018, recorded approximately three times as many B mesons as the original analysis used. The next analysis cycle will determine whether the signal converges toward five sigma or fades back into the predicted distribution. [2] The paper's Friday brief read the persistence at 8.4 fb⁻¹ as the hadronic-uncertainty defense getting harder to sustain; another day of Run 3 data does not change that.

The candidate explanations Quanta and the CERN Courier have catalogued — a hypothetical Z-prime gauge boson, a class of leptoquark particles connecting quarks and leptons — remain the leading new-physics frames. Neither has been independently observed. 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 with more data. The next analysis will tell whether the textbook needs an addendum or whether the anomaly is the longest-running near-miss in the field's modern history.

-- KENJI NAKAMURA, Tokyo