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arXiv · 2502.04721

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

Chien-Yeah Seng
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Abstract

I will give a brief overview of the Standard Model theory inputs needed for the precise determination of the Cabibbo-Kobayashi-Maskawa matrix element $V_{us}$ from semileptonic kaon decays, focusing on the long-distance electromagnetic corrections. I will then describe our recent effort to pin down this correction at sub-permille level, which further sharpens the so-called ``Cabibbo angle anomaly'', an interesting observation which may point towards new physics.

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Chien-Yeah Seng. 2025-02-07. Semileptonic kaon decays and the precise determination of $V_{us}$. https://arxiv.org/abs/2502.04721

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