Evidence for the $\mathrm{2\pi }$ Decay of the $K_2^0$ Meson

Christenson et al.’s 1964 Evidence for the 2π Decay of the K₂⁰ Meson, published in Physical Review Letters, is one of the program’s working technical references. Cited in Book IV (Categorical Microcosm), Part 3, Chapter The Weak Force and Chirality, where the program draws on it in the context of “CP violation was discovered in 1964 by Cronin and Fitch in neutral kaon decay.”