$K^+ \to \pi^+\nu\bar\nu$ measurement at the NA62 experiment

The high precision of the theoretical prediction and the strong suppression make the ultra-rare kaon decay $K^+ \to \pi^+\nu\bar\nu$ an excellent probe for new physics. The NA62 experiment at CERN SPS aims to measure $BR$($K$+ → $\pi$$^{+}$$\nu$$^{+}$$\bar{\nu}$) with a 10% precision. NA62 collected data in 2016, 2017 and 2018. The 2016 data has been analyzed and the result published: one candidate signal event was found, showing that the decay-in-flight technique works. The 2017 sample is currently under analysis and 2.5 ± 0.4 Standard Model signal events are expected, while the background is still under study.