Speaker
Description
We illustrate the results of our recent study of the rare kaon decay $K^{-}\to \ell'^{+}\ell'^{-}\ell^{-}\bar{\nu}_{\ell}$, known as $K_{\ell2\ell'}$ , based on Twisted-Clover simulations at the physical point carried out by ETM collaboration.
The $K_{\ell2\ell'}$ form factors, which have been recently submitted to arXiv:2605.22742, are extrapolated to the continuum limit using three lattice spacings, and the finite volume corrections are investigated using three different volumes. Emission of the photon from the sea is taken into account, and HLT-based methods are used to carry out the needed analytic continuation to Minkowskian spacetime.
The form factors are used to estimate the various lepton channel decay rates within the Standard Model, and to compare it with the existing experimental measurements, as presented in our recent arXiv:2605.22727