K meson


Also found in: Dictionary, Thesaurus, Wikipedia.

K meson

[′kā ¦mā‚sän]
(particle physics)
Collective name for four pseudo-scalar mesons, having masses of about 495 MeV (megaelectronvolts) and decaying via weak interactions: K +, K -, K 0S, and K 0L; they consist of two isotopic spin doublets, the (K +, K 0) doublet and its antiparticle doublet (K -, 0), having hypercharge or strangeness of +1 and -1 respectively, where K 0 and 0 are certain combinations of KL 0 and KS 0 states. Also known as kaon.
Collective name for any meson resonance belonging to an isotopic doublet with hypercharge +1 or -1, denoted KJP (m) or JP (m) respectively, where m is the mass in megaelectronvolts, and J and P are the spin and parity.
References in periodicals archive ?
Physicists discovered nearly 40 years ago that matter and antimatter versions of so-called K mesons decay slightly differently, a disparity called charge-parity, or CP, violation (SN: 3/6/99, p.
Fitch, now of Princeton University, and their colleagues revealed that nature--or at least particles called K mesons, or kaons--didn't behave as expected.
Bombardment with K mesons will turn neutrons or protons into strange particles.