The First Edition of the African Conference on High Energy Physics

Precision measurements with Kaon decays at the NA62 experiment

Not scheduled

20m

withdrawn QUARK AND LEPTON FLAVOR PHYSICS

Speaker

Angela Romano (University of Birmingham)

Description

The NA62 experiment at CERN collected the world's largest dataset of charged kaon decays in 2016-2018, leading to the first measurement of the branching ratio of the ultra-rare $K^{+}\to {\pi }^{+}\nu \overline{\nu }$ decay, based on 20 candidates. In this talk the NA62 experiment reports recent results from analyses of $K^{+}\to {\pi }^0{e}^{+}\nu \gamma$, $K^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ and $K^{+}\to {\pi }^{+}\gamma \gamma$ decays, using a data sample recorded in 2017-2018. The radiative kaon decay $K^{+}\to {\pi }^0{e}^{+}\nu \gamma$ (Ke3g) is studied with a data sample of O(100k) Ke3g candidates with sub-percent background contaminations. Results with the most precise measurements of the Ke3g branching ratios and T-asymmetry are presented. The $K^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ sample comprises about 27k signal events with negligible background contamination, and the presented analysis results include the most precise determination of the branching ratio and the form factor. The $K^{+}\to {\pi }^{+}\gamma \gamma$ sample contains about 4k signal events with $10\mathrm{\%}$ background contamination, and the analysis improves the precision of the branching ratio measurement by a factor of 3 with respect to the previous measurements.