Z-mediated charge and CP asymmetries and FCNCs in $B_{d,s}$ processes

Abstract

We show model-independently that the negative like-sign charge asymmetry $(-A_{s\ell }^b)$ is less than $3.16\times 10^{-3}$ when the constraints from the $B_q-{\bar{B}}_q$ mixings and the time-dependent CP asymmetries (CPAs) for $B_q\to J/\Psi M_q$ with $M_q=K,\varphi$ and $q=d,s$ are taken into account. Although the result is smaller than the measured value by the DØ Collaboration at Fermilab, there is still plenty of room to have new physics, which is sensitive to new CP violating effects, as the standard model (SM) prediction is $(2.3_{-0.5}^{+0.6})\times 10^{-4}$. To illustrate the potential large $|A_{s\ell }^b|$, we show the influence of new $SU(2{)}_L$ singlet exotic quarks in the vector-like quark model, where the $Z$-mediated flavor changing neutral currents (FCNCs) are generated at tree level. In particular, we demonstrate that (a) the like-sign charge asymmetry could be enhanced by a factor of two in magnitude; (b) the CPA of $\sin 2{\beta }_s^{J/\Psi \varphi }$ could reach to $-15$; (c) the CPA of $\sin 2{\beta }_{\varphi K_S}$ could be higher than $\sin 2{\beta }_{J/\Psi K_S}$ when $|A_{s\ell }^b|$ is larger than the SM prediction; and (d) the branching ratio for $B_s\to {\mu }^{+}{\mu }^{-}$ could be as large as $0.6\times 10^{-8}$.

1+19 pages, 8 figures, typos corrected and references added, version to appear in JHEP

References in corpus (7)

• Neutral B Meson Mixing in Unquenched Lattice QCD
• Less space for a new family of fermions
• Unparticle physics effects in B_s mixing
• A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC
• Mixing and lifetimes of $b$-hadrons
• New Physics from Flavour
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Cited by in corpus (9)

• Anatomy of New Physics in B-Bbar mixing
• Ultra Visible Warped Model From Flavor Triviality & Improved Naturalness
• Neutral Gauge Boson Contributions to the Dimuon Charge Asymmetry in B Decays
• CP Violating Contribution to Delta Gamma in the B_s System from Mixing with a Hidden Pseudoscalar
• The D0 same-charge dimuon asymmetry and possibile new CP violation sources in the $B_s-{\bar{B}}_s$ system
• Triangle Relation of Dark Matter, EDM and CP Violation in B0 Mixing in a Supersymmetric Q6 Model
• Reevaluating R-parity Violating Supersymmetry Effects in B_s^0-\bar{B}_s^0 Mixing
• b -> s Decays in a model with Z-mediated flavor changing neutral current
• Flavour Theory and the LHC Era