The NA62 experiment at CERN measures the ultra-rare decay K+ ➞ π+νν̄, which has a branching fraction of less than 10^-10 and is extremely sensitive to possible contributions from New Physics beyond the Standard Model. A first data-taking period yielded 20 candidates and the on-going run will reach about 100 K+ ➞ π+νν̄ events. The planned successor HIKE will further improve the precision and also measure rare K_L decays, while the planned SHADOWS experiment will use the same beam-line to search for feebly interacting new particles.
Oleh Kivernyk, Tatjana Lenz