Pith. sign in

REVIEW 6 cited by

Scrutinizing CKM unitarity with a new measurement of the $K_{\mu 3}/K_{\mu 2}$ branching fraction

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2208.11707 v2 pith:CGIMB7TQ submitted 2022-08-24 hep-ph hep-exhep-latnucl-th

classification hep-phhep-exhep-latnucl-th
keywords decayskaonmeasurementunitaritybranchingcurrentlyfractionlevel
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

Precision tests of first-row unitarity of the Cabibbo-Kobayashi-Maskawa matrix currently display two intriguing tensions, both at the $3\sigma$ level. First, combining determinations of $V_{ud}$ from superallowed $\beta$ decays with $V_{us}$ from kaon decays suggests a deficit in the unitarity relation. At the same time, a tension of similar significance has emerged between $K_{\ell 2}$ and $K_{\ell 3}$ decays. In this Letter, we point out that a measurement of the $K_{\mu3}/K_{\mu 2}$ branching fraction at the level of $0.2\%$ would have considerable impact on clarifying the experimental situation in the kaon sector, especially in view of tensions in the global fit to kaon data as well as the fact that the $K_{\mu2}$ channel is currently dominated by a single experiment. Such a measurement, as possible for example at NA62, would further provide important constraints on physics beyond the Standard Model, most notably on the role of right-handed vector currents.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Pion $\beta$ decay and $\tau\to\pi\pi\nu_\tau$ beyond leading logarithms

    hep-ph 2026-02 conditional novelty 7.0 of 10

    Pion β decay and τ→ππν short-distance radiative corrections are matched at NLL accuracy with evanescent-scheme dependence cancelled, giving Δ_RC^{πℓ}=0.03403(11) and a τ-HVP isospin-breaking shift of −0.07(4)×10^-10.

  2. Challenging Majorana neutrino effects in $B\to K^{(\ast)}\nu\nu$ and $K\to \pi\nu\nu$ decays

    hep-ph 2026-07 conditional novelty 6.0 of 10

    Belle-II's B→Kνν excess cannot be explained by dimension-7 lepton-number-violating SMEFT operators without fine-tuning neutrino masses, while a light sterile-neutrino extension can, with testable decay spectra.

  3. Flavor constraints from $pp\to Vh$ and $pp\to VW$ at the LHC

    hep-ph 2025-09 conditional novelty 6.0 of 10

    LHC data on pp→Vh and pp→VW yield general-flavor SMEFT constraints that will become competitive with flavor tests of the Cabibbo-angle anomaly at the HL-LHC.

  4. Quantum Monte Carlo calculation of $\delta_{\rm NS}$ in $^{10}$C using an effective field theory approach

    nucl-th 2025-09 conditional novelty 6.0 of 10

    The first quantum Monte Carlo evaluation of the nuclear-structure-dependent radiative correction in carbon-10 confirms the NCSM dispersion result, with the residual uncertainty set by two undetermined low-energy constants.

  5. Characterization of Low-energy Ionization Signals in Silicon Detectors for the Nab Experiment

    physics.ins-det 2025-11 conditional novelty 4.0 of 10

    Proton energy response of Nab's silicon detectors was stable over a year, with a dead layer of about 55 nm, and the timing model predicts proton time-of-flight bias uncertainty below 0.3 ns.

  6. Semileptonic kaon decays and the precise determination of $V_{us}$

    hep-ph 2025-02 unverdicted novelty 2.0 of 10

    A hybrid chiral perturbation theory and lattice QCD treatment of radiative corrections to kaon semileptonic decays is claimed to reach 10^-4 precision, yielding V_us = 0.22308(39)(39)(3) and sharpening the Cabibbo ang...

Pith tools