A measurement of the $K^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ decay

Abstract

A sample of $2.8\times 10^4$ $K^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ candidates with negligible background was collected by the NA62 experiment at the CERN SPS in 2017--2018. The model-independent branching fraction is measured to be $(9.15\pm 0.08)\times 10^{-8}$, a factor three more precise than previous measurements. The decay form factor is presented as a function of the squared dimuon mass. A measurement of the form factor parameters and their uncertainties is performed using a description based on Chiral Perturbation Theory at $\mathcal{O}(p^6)$.

17 pages, 5 figures. Updated version (6 October 2022) accepted for publication in JHEP

References in corpus (3)

• The integrated low-level trigger and readout system of the CERN NA62 experiment
• Soft-photon corrections in multi-body meson decays
• Radiative corrections in K --> pi l+ l- decays