Isosinglet down quark mixing and CP violation experiments

We confront the new physics models with extra isosinglet down quarks in the new CP violation experimental era with sin(2β) and ε′/ε measurements, K+→π+ νν-events, and xs limits. The closeness of the new experimental results to the standard model theory requires us to include full standard model (SM) amplitudes in the analysis. In models allowing mixing to a new isosinglet down quark, as in E6, flavor changing neutral currents are induced that allow a Z0 mediated contribution to B-B mixing and which bring in new phases. In (p, η), (xs,sin(γ)), and (xs,sin(2φs)) plots we-still find much larger regions in the four down quark model than in the SM, reaching down to η≈0, 0≤sin(γ)≤1, -0.75≤sin(2α)≤0.15, and sin(2φs) down to zero, all at 1 σ. We elucidate the nature of the cancellation in an order λ5 four down quark mixing matrix element which satisfies the experiments and reduces the number of independent angles and phases. We. also evaluate tests of unitarity for the 3 × 3 Cabibbo-Kobayashi-Maskawa submatrix