B⁰-B⁰ mixing, CP violation, K⁺→π⁺νν and B→KγX in a two-Higgs-doublet model

B⁰-B⁰ mixing, the ε{lunate}_K parameter, the ratio ( ε{lunate}′ ε{lunate})_K and the decays K⁺→π⁺ν ν and B→KγX are studied in the framework of a two-Higgs-doublet model in which charged Higgs bosons are present. The fitted value of sinδ_KM in this model differs from the one obtained in the absence of charged Higgs effects. The ratio ε{lunate}′ ε{lunate} is found to be substantially smaller than in the standard model, typically ε{lunate}′ ε{lunate} ≈ (1.0 ± 0.5) × 10^-3. Our results for BR(K⁺ → π⁺νν) showing a suppression relative to the standard model prediction differ from those present in the literature; however, the branching ratio BR(B → KγX) is enhanced. Bounds on the charged Higgs masses and couplings to fermions are found as a function of the top quark mass.