[en] The K/sub L/ → 2γ decay is examined in the context of gauge models of weak and electromagnetic interactions. It is shown that the decay is possible because of the existence of an anomaly in the divergence of the axial vector current that transforms like lambda₆ under SU(3). The existence of such an anomaly is first shown in an SU(2) x U(1) gauge model containing only the familar quarks, and then generalized and calculated for the realistic case of the SU(4) model of Glashow, Iliopoulos, and Maini. The K/sub L/ → 2γ rate is obtained as a function of the amount of SU(4) breaking, which is determined to be of the order of 1.5 GeV². In addition, the K/sub L/ → anti-μ-μ decay is examined within the context of the above models and is shown to be sufficiently suppressed. Moreover, the examination of K/sub s/ → π⁺π^- decay and K/sub L/ → K/sub s/ mass difference leads to an interesting relation independent of mass parameters. Also, in the case of the SU(4) model, the calculation of those processes leads to the determination of the quark mass parameters