Papers · William Alexander Aldred

The Cabibbo Ledger: A Factor Census of the First-Row CKM Deficit, Graded Against the Coherent Floor of Its Own Inputs

Published October 29, 2026 · Zenodo · DOI: 10.5281/zenodo.23779712

About this paper

The first row of the CKM matrix should sum to one. With the Particle Data Group’s current inputs it sums to 0.9983(6)(4), a deficit Δ_CKM = −0.0017 ± 0.0007 — the Cabibbo angle anomaly, at about 2σ on the headline inputs, near 4σ on the tau-decay value of |V_us|, and near zero on the neutron-decay value of |V_ud|. This paper spends the factor census on that row: thirteen classes closed in advance, seven on the input side and six on the new-physics side, each graded against the coherent floor of its own inputs. Three input classes and three new-physics classes survive the floor; five classes die, two of them only as sole movers. No class closes the row inside its own stated errors — a single input would have to move 2.7 of its own standard deviations in |V_ud|, or 4.5 in |V_us|, to do the whole job alone — and the spread of the row across legitimate input sets is 0.0030, wider than the deficit it is asked to explain. Graded at full size: the deficit stands between 1.4σ and 2.4σ once the nine quoted forms are counted as looks. That is a ledger that does not close — and this paper claims neither a solution nor new physics.

Paper 43 of 95 in the published register. The full text is published on Zenodo under a permanent DOI: 10.5281/zenodo.23779712.

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