K+→π+νν with four generations and its effects on unitarity triangle

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We analyze in the four-generation model the first measurement of the branching ratio of rare kaon decay K+→π+νν, using the constraints from Δmₖ, εₖ, Bd-Bd mixing, Γ(b→ sγ), Bₛ-Bₛ mixing, D⁰-D⁰ mixing, B(Kₗ→π⁰νν) and B(Kₗ→μμ), and study its effects on the unitarity triangle. With the results of searching for the maximum mixing of the fourth generation, we predict that D⁰-D⁰ mixing ΔmD and the branching ratio of "direct" CP-violating decay process Kₗ→π⁰νν could attain the values 1-2 orders of magnitude larger than the predictions of the Standard Model.