The fourth family: A simple explanation for the observed pattern of anomalies in B - CP asymmetries

Abstract

We show that a fourth family of quarks with mt′ in the range of (400-600) GeV provides a rather simple explanation for the several indications of new physics that have been observed involving CP asymmetries of the b-quark. The built-in hierarchy of the 4 × 4 mixing matrix is such that the t′ readily provides a needed perturbation (≈ 15 %) to sin 2 β as measured in B → ψ Ks and simultaneously is the dominant source of CP asymmetry in Bs → ψ φ{symbol}. The correlation between CP asymmetries in Bs → ψ φ{symbol} and Bd → φ{symbol} Ks suggests mt′ ≈ (400 - 600) GeV. Such heavy masses point to the tantalizing possibility that the 4th family plays an important role in the electroweak symmetry breaking. © 2009 Elsevier B.V.