XIII International Conference on Kaon Physics -- Kaon 2025 Mainz

Session

Semileptonic & Radiative Decays

11 Sept 2025, 15:30

Alte Mensa (Johannes Gutenberg University Mainz)

83. Rare Semileptonic Kaon Decay

Ryan Hill

11/09/2025, 15:30

Semileptonic and Radiative Kaon Decays

Oral Contribution

xxx

69. Application of K ➞ 3π amplitudes to semileptonic kaon decays

Jack Jenkins (Universität Siegen)

11/09/2025, 15:55

Semileptonic and Radiative Kaon Decays

Oral Contribution

We implement a dispersive parameterization of the nonlocal form factors (NFFs) governing photon or $Z$-boson exchange in the semileptonic $K^+ \to \pi^+ \ell^+ \ell^-$ $(\ell=e,\mu)$ and $K^+ \to \pi^+ \nu \bar{\nu}$ decays, respectively, to improve the theoretical description of the spectrum and decay rate of the golden neutrino mode. The parameterization links the hadronic $K^+ \pi^- \to...

55. Kaon radiative leptonic decay rates from lattice QCD simulations at the physical point

Mr Roberto Di Palma (Università Roma Tre, Infn, sezione di Roma Tre)

11/09/2025, 16:45

Semileptonic and Radiative Kaon Decays

Oral Contribution

We present a Lattice QCD calculation of the radiative decay rates of the kaon $K^- \to \ell^- \bar{\nu}_{\ell} \gamma^{(*)}$, with a real or virtual photon, and $\ell = e, \mu$. The simulations are performed with physical kaon and pion masses, using gauge ensembles generated by the Extended Twisted Mass Collaboration with $N_f = 2+1+1$ flavors of Wilson-Clover twisted mass fermions.
For...

45. Results of radiative kaon decay studies at NA62

Zdenko Hives (Charles University (CZ))

11/09/2025, 17:05

Semileptonic and Radiative Kaon Decays

Oral Contribution

The NA62 experiment at CERN reports preliminary results from the study of the rare radiative decay $K^+ \rightarrow \pi^+ \pi^+ \pi^- \gamma$, using a data sample collected with a multi-track trigger in 2017-2018. A measurement of the branching ratio as a function of the photon energy in the kaon rest frame is presented and compared with previous measurements and theoretical predictions.

94. Lattice QCD Calculation of Radiative Corrections to Meson Leptonic Decays

Xin-Yu Tuo (Brookhaven national laboratory)

11/09/2025, 17:25

Semileptonic and Radiative Kaon Decays

Oral Contribution

Precise tests of CKM unitarity provide a probe of physics beyond the Standard Model. Using the most precise determinations—$V_{ud}$ from superallowed nuclear $\beta$ decays and $V_{us}$ from kaon leptonic and semileptonic decays—the first‑row sum $|V_{ud}|^{2}+|V_{us}|^{2}+|V_{ub}|^{2}$ deviates from unitarity by $2\text{–}3\,\sigma$. This tension emphasizes the need for further reductions in...

99. Measurement of the K+ ➞ e+ ν γ decay at NA62

Angela Romano (University of Birmingham (GB))

11/09/2025, 17:45

Rare Decays

Oral Contribution

79. Kaon Physics in the Standard Model Effective Field Theory Framework

Jason Aebischer (CERN)

12/09/2025, 09:20

Semileptonic and Radiative Kaon Decays

Oral Contribution

In my talk I will present an overview of Kaon observables analyzed within the Standard Model Effective Field Theory (SMEFT) framework. Focusing on Kaon mixing, rare decays, and direct CP violation, I will discuss how these processes constrain higher-dimensional SMEFT operators. The treatment includes renormalization group evolution, matching to the low-energy effective theory, and the role of...

84. QED Overview

Matteo Di Carlo

12/09/2025, 09:45

Semileptonic and Radiative Kaon Decays

Oral Contribution

xxx