Probing the $Zb\bar{b}$ anomalous couplings via exclusive $Z$ boson decay

Abstract

We propose to utilize the exclusive $Z$-boson rare decays $Z\to {\rm Y}(ns)+\gamma$ to constrain the $Zb\bar{b}$ couplings at the HL-LHC and 100 TeV proton-proton collider. We demonstrate that the event yield of the proposed processes is sensitive to the axial-vector component of the $Zb\bar{b}$ coupling and can provide complementary information to the jet-charge weighted single-spin asymmetry measurement at the EIC and the $gg\to Zh$ production rate measurement at the LHC. By applying the NRQCD factorization formalism, we calculate the partial decay width of $Z\to {\rm Y}(ns)+\gamma$ to the NLO accuracy in strong interaction, which is found to agree with those obtained from the light-cone distribution amplitude approach. We show that the HL-LHC can break the degeneracy of the $Zb\bar{b}$ couplings, as implied by the precision electroweak data at LEP and SLC, if the signal efficiency can be improved by a factor of 1.7 from the present ATLAS analysis at the 13 TeV LHC with an integrated luminosity of $36.1{\mathrm{fb}}^{-1}$.

arXiv comment7 pages, 4 figures, published in PLB

References in corpus (14)

• Asymptotic formulae for likelihood-based tests of new physics
• Rigorous QCD Analysis of Inclusive Annihilation and Production of Heavy Quarkonium
• A custodial symmetry for Zbb
• The renormalization of the axial anomaly in dimensional regularization
• Patterns of Deviation from the Standard Model
• Two-loop Correction to the Leptonic Decay of Quarkonium
• QCD Corrections to Inelastic $J/\psi$ Photoproduction
• Next-to-leading-log renormalization-group running in heavy-quarkonium creation and annihilation
• Searches for exclusive Higgs and $Z$ boson decays into $J/\psi \gamma$, $\psi (2S)\gamma$, and ${\rm Y}(nS)\gamma$ at $\sqrt{s}=13$ TeV with the ATLAS detector
• Leptonic decay of the Upsilon(1S) meson at third order in QCD
• Next-to-leading nonperturbative calculation in heavy quarkonium
• NRQCD matrix elements for S-wave bottomonia and Gamma[eta_b(nS) -> gamma gamma] with relativistic corrections
• $Z$-boson decays to a vector quarkonium plus a photon
• Precision Electroweak Analysis after the Higgs Boson Discovery

Cited by in corpus (10)

• Rare and exclusive few-body decays of the Higgs, Z, W bosons, and the top quark
• Probing Top-quark Operators with Precision Electroweak Measurements
• $Z$ boson radiative decays to a $P$-wave quarkonium at NNLO and LL accuracy
• $Z$ boson radiative decays to a $S$-wave quarkonium at NNLO and NLL accuracy
• Note on rare $Z$-boson decays to double heavy quarkonia
• Probing the $H\gamma \gamma$ coupling via Higgs exclusive decay into quarkonia plus a photon at the HL-LHC
• Probing top-quark electroweak couplings indirectly at the Electron-Ion Collider
• Accommodating the CDF W-boson Mass Measurement in the Beautiful Mirror Model
• The $Zb\bar{b}$ vertex in a left-right model
• Tracing the bottom electroweak dipole operators at future lepton colliders