Constraints on anomalous $tcZ$ coupling from $\bar{B}\to {\bar{K}}^{\ast }{\mu }^{+}{\mu }^{-}$ and $B_s\to {\mu }^{+}{\mu }^{-}$ decays

Abstract

In this paper, we analyze the possible anomalous $tcZ$ coupling effects in the $b\to s$ mediated decays $\bar{B}\to {\bar{K}}^{\ast }{\mu }^{+}{\mu }^{-}$ and $B_s\to {\mu }^{+}{\mu }^{-}$. After exploiting the available experimental data, the combined constraints on the anomalous coupling $X_{ct}^L$ are derived. It is found that, the bound on the magnitude $|X_{ct}^L|$ is dominated by the branching ratios of these two decays. Furthermore, one sign-flipped solution is excluded by the longitudinal fraction of $\bar{B}\to {\bar{K}}^{\ast }{\mu }^{+}{\mu }^{-}$ at the low dilepton mass region. After considering the combined constraints, for general complex coupling $X_{ct}^L$, the predicted upper bound on $\mathcal{B}(t\to cZ)$ are compatible with that from the recent CMS direct search. In particular, for the case of real coupling $X_{ct}^L$, the upper bound reads $\mathcal{B}(t\to cZ)<1.0\times 10^{-4}$, which is much lower than the current CMS bound but still accessible at the LHC. With improved measurements at the LHC, the colser correlations between the $t\to cZ$ and $b\to s$ mediated (semi-) leptonic decays are expected in the near future.

23 pages, 9 figures, 2 tables. v3: effects due to the width difference ΔΓ_s added, numerical results and figure.3 and 4 slightly changed, main conclusions of the paper remain the same, matches published version in JHEP

References in corpus (13)

• Measurement of the Differential Branching Fraction and Forward-Backword Asymmetry for B->K(*)l+l-
• First evidence for the decay Bs -> mu+ mu-
• Probing New Physics via the $B_s^0\to {\mu }^{+}{\mu }^{-}$ Effective Lifetime
• Branching Ratio Measurements of $B_s$ Decays
• $B\to K{\ell }^{+}{\ell }^{-}$ decay at large hadronic recoil
• Deciphering top flavor violation at the LHC with B factories
• Penguins with Charm and Quark-Hadron Duality
• Next-to-leading order QCD corrections to the top quark decay via model-independent FCNC couplings
• Bayesian Fit of Exclusive $b\to s\bar{\ell }\ell$ Decays: The Standard Model Operator Basis
• Search for flavor changing neutral currents in top quark decays in pp collisions at 7 TeV
• Interplay of t --> b W Decay and B_q Meson Mixing in Minimal Flavor Violating Models
• QCD Corrections to Flavor Changing Neutral Coupling Mediated Rare Top Quark Decays
• B -> Xsγconstraints on the top quark anomalous t-> cγcoupling

Cited by in corpus (10)

• A global approach to top-quark flavor-changing interactions
• Time dependence in $B\to V\ell \ell$ decays
• More Synergies from Beauty, Top, $Z$ and Drell-Yan Measurements in SMEFT
• Probing anomalous $t\bar{t}Z$ interactions with rare meson decays
• Implications of the $R_K$ and $R_{K^{\ast }}$ anomalies
• Limits on the anomalous $Wtq$ couplings
• Leveraging on-shell interference to search for FCNCs of the top quark and the Z boson
• Top-quark flavor-changing $tqZ$ couplings and rare $\Delta F=1$ processes
• Flavor signatures of complex anomalous $tcZ$ couplings
• Non-diagonal contributions to $Z\gamma V^{\ast }$ vertex, polarizations and bounds on $Z\overline{t}q$ couplings