Constraining Extensions of the Quark Sector with the CP Asymmetry in $B\to \psi K_S$

Abstract

Models with extended quark sector affect the CP asymmetry in the $B\to \psi K_S$ decay, $a_{\psi K_S}$, in two ways: First, the top-mediated box diagram is not necessarily the only important contribution to $B-\bar{B}$ mixing. Second, the $3\times 3$ CKM matrix is no longer unitary. We analyze the constraints that follow from the CDF measurement, $a_{\psi K_S}=0.79_{-0.44}^{+0.41}$, on the mixing parameters of extended quark sectors. Most noticeably, we find significant constraints on the phase of the relevant flavor changing $Z$ coupling in models with extra down quarks in vector-like representations. Further implications for the CP asymmetry in semileptonic $B$ decays are discussed.

12 pages, LaTeX, 3 figures

Cited by in corpus (9)

• Effects of mixing with quark singlets
• Implications of the CP asymmetry in semileptonic B decay
• Constraining models with vector-like fermions from FCNC in K and B physics
• Tree-level FCNC in the B system: from CP asymmetries to rare decays
• Constraining Models of New Physics in Light of Recent Experimental Results on $a_{\psi K_S}$
• Phenomenological Constraints on Extended Quark Sectors
• Novel CP-violating Effects in B decays from Charged-Higgs in a Two-Higgs Doublet Model for the Top Quark
• Non-unitarity of CKM matrix from the vector singlet quark mixing and neutron electric dipole moment
• Mixing asymmetries in B meson systems, the D0 like-sign dimuon asymmetry and generic New Physics