Kmeson
K meson, or kaon, is a meson that contains a strange quark or antiquark. It is a spin-0 pseudoscalar hadron. The lightest kaons form a family of four: K+, K-, K0, and anti-K0. Their quark contents are K+ = u s̄, K- = ū s, K0 = d s̄, and anti-K0 = s d̄. Charged kaons carry electric charge ±1, while neutral kaons are neutral. Kaons are produced in high-energy hadron collisions and in cosmic-ray interactions, and they decay weakly with lifetimes ranging from about 10^-8 to 10^-10 seconds.
In the neutral kaon system, K0 and anti-K0 can transform into each other via second-order weak interactions.
The neutral kaon system was central to the discovery of CP violation in 1964, observed in KL
Kaons remain important probes of flavor physics, weak interactions, and fundamental symmetries, with ongoing studies of