Speaker
Description
We present results for $f_K/f_{\pi}$ in pure QCD with $N_f=2+1$ flavors, along with a determination of $|V_{us}|$ and a study on the unitarity of the first row of the Cabibbo-Kobayashi-Maskawa (CKM) matrix after introducing strong isospin-breaking and QED effects.
The results obtained are based on a combination of a Wilson unitary action and a mixed action setup using Wilson twisted mass fermions in the valence. In both setups, the sea sector employs non-perturbatively $\mathcal{O}(a)$-improved Wilson fermions, using CLS $N_f=2+1$ ensembles.
The combination of the two regularizations enables a more precise control over the continuum limit extrapolation, as both setups must share the same continuum limit, yet can exhibit distinct cutoff effects.
| Parallel Session (for talks only) | Quark and lepton flavor physics |
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