Rare decays are fundamental probes for physics beyond the Standard Model, and the expanding LHCb program on strange physics provides unique and complementary information with respect to the beauty and charm sectors. Recent results of rare kaon decays at LHCb will be summarized and prospects for strange physics with LHCb Upgrade I, where the change in trigger strategy will allow for a much...
The first observation of the $K^+\to\mu^+\nu\mu^+\mu^-$ decay with the 2016-2024 dataset collected by the NA62 experiment is presented. The branching ratio of the process is measured relative to the normalisation channel $K^+\to\pi^+\mu^+\mu^-$, taking advantage of similar final states and both decays being collected by the same trigger stream. The dominant background is the $K^+\to...
The NA62 experiment at CERN reports recent results from precision measurements of kaon and pion decays, using data samples collected in 2017-2018. A sample of $K^+ \rightarrow \pi^+ \gamma \gamma$ decays is collected using a minimum-bias trigger, and the results include measurement of the branching ratio, study of the di-photon mass spectrum, and the first search for production and prompt...
