Key Facts

Physicists working on the NA62 experiment at the European Organization for Nuclear Research (CERN) in Geneva announced the first statistically significant measurement of the ultra-rare decay of a positively charged kaon into a positive pion and a neutrino-antineutrino pair (K+ → π+νν). Occurring less than once in 10 billion decays, this elusive subatomic process provides physicists with one of the most rigorous tests of the Standard Model of particle physics. Because theoretical predictions for this decay rate are exceptionally clean and free from strong force uncertainties, any deviation between experimental observations and Standard Model calculations offers a golden window to discover 'New Physics' beyond the Standard Model, such as dark matter candidates or heavy sterile neutrinos.

GK Context

The Standard Model is the foundational theoretical framework describing three of the four fundamental forces of nature (electromagnetic, weak, and strong interactions, excluding gravity) and classifying all known elementary subatomic particles (quarks, leptons, and gauge bosons). Kaons are subatomic mesons consisting of a strange quark and an up or down antiquark, first discovered in cosmic rays in 1947. India is an Associate Member State of CERN, with Indian scientists, premier institutes such as the Tata Institute of Fundamental Research (TIFR), Bhabha Atomic Research Centre (BARC), and Saha Institute of Nuclear Physics (SINP), contributing extensively to the Large Hadron Collider (LHC) and advanced particle detector instrumentation.