Identifying a $Z^{\prime }$ behind $b\to s\ell \ell$ anomalies at the LHC

Abstract

Recent $b\to s\ell \ell$ anomalies may imply the existence of a new $Z^{\prime }$ boson with left-handed $Z^{\prime }bs$ and $Z^{\prime }\mu \mu$ couplings. Such a $Z^{\prime }$ may be directly observed at LHC via $b\bar{s}\to Z^{\prime }\to {\mu }^{+}{\mu }^{-}$, and its relevance to $b\to s\ell \ell$ may be studied by searching for the process $gs\to Z^{\prime }b\to {\mu }^{+}{\mu }^{-}b$. In this paper, we analyze the capability of the 14 TeV LHC to observe the $Z^{\prime }$ in the ${\mu }^{+}{\mu }^{-}$ and ${\mu }^{+}{\mu }^{-}b$ modes based on an effective model with major phenomenological constraints imposed. We find that both modes can be discovered with 3000 fb${}^{-1}$ data if the $Z^{\prime }bs$ coupling saturates the latest $B_s-{\bar{B}}_s$ mixing limit from UTfit at around $2\sigma$. Besides, a tiny right-handed $Z^{\prime }bs$ coupling, if it exists, opens up the possibility of a relatively large left-handed counterpart, due to cancellation in the $B_s-{\bar{B}}_s$ mixing amplitude. In this case, we show that even a data sample of $\mathcal{O}(100)$ fb${}^{-1}$ would enable discovery of both modes. We further study the impact of a $Z^{\prime }bb$ coupling as large as the $Z^{\prime }bs$ coupling. This scenario enables discovery of the $Z^{\prime }$ in both modes with milder effects on the $B_s-{\bar{B}}_s$ mixing, but obscures the relevance of the $Z^{\prime }$ to $b\to s\ell \ell$. Discrimination between the $Z^{\prime }bs$ and $Z^{\prime }bb$ couplings may come from the production cross section for the $Z^{\prime }b\bar{b}$ final state. However, we do not find the prospect for this to be promising.

explanations and references added, matches with the published version

References in corpus (35)

• PYTHIA 6.4 Physics and Manual
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions
• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Secluded U(1) below the weak scale
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• Neutrino Trident Production: A Powerful Probe of New Physics with Neutrino Beams
• ZZ production at hadron colliders in NNLO QCD
• Explaining $h\to {\mu }^{\pm }{\tau }^{\mp }$, $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and $B\to K{\mu }^{+}{\mu }^{-}/B\to K{e}^{+}{e}^{-}$ in a two-Higgs-doublet model with gauged $L_{\mu }-L_{\tau }$
• Addressing the LHC flavour anomalies with horizontal gauge symmetries
• $W^{+}{W}^{-}$ production at hadron colliders in NNLO QCD
• Two-Loop Electroweak Corrections for the K -> pi nu anti-nu Decays
• Search for new high-mass phenomena in the dilepton final state using 36 fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Simultaneous Explanation of the $R_K$ and $R(D^{(\ast )})$ Puzzles
• Current status of the Standard Model CKM fit and constraints on $\Delta F=2$ New Physics
• Anatomy of New Physics in B-Bbar mixing
• Family non-universal Z' models with protected flavor-changing interactions
• Lepton flavor violating Z' explanation of the muon anomalous magnetic moment
• Measurement of angular parameters from the decay ${\mathrm{B}}^0\to {\mathrm{K}}^{\ast 0}{\mu }^{+}{\mu }^{-}$ in proton-proton collisions at $\sqrt{s}=$ 8 TeV
• Constraints on new physics from the quark mixing unitarity triangle
• One constraint to kill them all?
• The Anatomy of Z' and Z with Flavour Changing Neutral Currents in the Flavour Precision Era
• Shedding light on the $b\to s$ anomalies with a dark sector
• Implications of $b\to s$ measurements
• Neutrino mixing and $R_K$ anomaly in $U(1{)}_X$ models: a bottom-up approach
• A "Vector-like chiral" fourth family to explain muon anomalies
• Flavourful $Z^{\prime }$ models for $R_{K^{(\ast )}}$
• The Case for Future Hadron Colliders From $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$ Decays
• On Light Resonance Interpretations of the B Decay Anomalies
• Connecting $b\to s\ell \bar{\ell }$ anomalies to enhanced rare nonleptonic ${\bar{B}}_s^0$ decays in $Z^{\prime }$ model
• LHC Search for Right-handed Neutrinos in $Z^{\prime }$ Models
• $R_K$ anomalies and simplified limits on $Z^{\prime }$ models at the LHC
• $B$ decay anomalies from nonabelian local horizontal symmetry
• Right-handed Neutrino Dark Matter in a U(1) Extension of the Standard Model
• Flavor physics induced by light $Z^{\prime }$ from SO(10) GUT

Cited by in corpus (19)

• Complete Vector-like Fourth Family and new $\mathrm{U}(1{)}^{\prime }$ for Muon Anomalies
• Explaining $b\to s{\ell }^{+}{\ell }^{-}$ and the Cabibbo Angle Anomaly with a Vector Triplet
• $Z^{\prime }$ models with less-minimal flavour violation
• Flavor anomalies and dark matter in SUSY with an extra U(1)
• Global Analysis of Leptophilic Z' Bosons
• Combined Explanation of the $Z\to b\bar{b}$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau \to \mu \nu \nu$ and $b\to s{\ell }^{+}{\ell }^{-}$ Data
• Complete Vector-like Fourth Family with ${\mathrm{U}(1)}^{\prime }$: A Global Analysis
• $R(K^{(\ast )})$ from dark matter exchange
• Unified Explanation of the Anomalies in Semi-Leptonic $B$ decays and the $W$ Mass
• Hadron Collider Sensitivity to Fat Flavourful $Z^{\prime }$s for $R_{K^{(\ast )}}$
• Towards excluding a light $Z^{\prime }$ explanation of $b\to s{\ell }^{+}{\ell }^{-}$
• Associated $Z^{\prime }$ production in the flavorful $U(1)$ scenario for $R_{K^{(\ast )}}$
• Probing an additional bottom Yukawa coupling via $bg\to bA\to bZH$ signature
• Implication of family non-universal $Z^{\prime }$ model to rare exclusive $b\to s(l\bar{l},\nu \bar{\nu })$ transitions
• Rare nonleptonic ${\bar{B}}_s^0$ decays as probes of new physics behind $b\to s\mu \bar{\mu }$ anomalies
• $\mu$-$\tau$ symmetry breaking and CP violation in the neutrino mass matrix
• The ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\mu }^{+}{\mu }^{-}$ decay in the ${\text{RS}}_c$ model
• An $SU(5)\times U(1{)}^{\prime }$ SUSY GUT with a "vector-like chiral" fourth family to fit all low energy data, including the muon $g-2$
• $\ge 4\mu$ signal from a vector-like lepton decaying to a muon-philic $Z^{\prime }$ boson at the LHC