$K$- and $D_{(s)}$-meson leptonic decay constants with physical light, strange and charm quarks by ETMC

TL;DR

This paper reports on lattice QCD calculations of leptonic decay constants for $K$, $D$, and $D_s$ mesons using physical quark masses, providing insights into meson properties and CKM matrix unitarity.

Contribution

The study introduces new lattice QCD results for meson decay constants with physical light, strange, and charm quarks using $N_f=2+1+1$ simulations by ETMC.

Findings

Decay constants for $K$, $D$, and $D_s$ mesons computed.

Preliminary unitarity checks for CKM matrix performed.

Results support the Standard Model predictions.

Abstract

We present a lattice QCD computation and preliminary results for the leptonic decay constants of the pseudoscalar mesons $K$, $D$ and $D_{s}$ in the isosymmetric QCD limit. The computation is based on simulations of $N_f = 2+1+1$ dynamical quarks performed by the Extended Twisted Mass Collaboration (ETMC), where the light, strange and charm quark masses are all tuned at their physical values. We also present preliminary unitarity checks for the first and second rows of the Cabibbo-Kobayashi-Maskawa matrix.