ATLAS on-Z Excess Through Vector-Like Quarks

Abstract

We investigate the possibility that the excess observed in the leptonic-$Z+$jets $+\slashed{E}_T$ ATLAS SUSY search is due to pair productions of a vector-like quark $U$ decaying to the first-generation quarks and $Z$ boson. We find that the excess can be explained within the 2$\sigma$ (up to 1.4$\sigma$) level while evading the constraints from the other LHC searches. The preferred range of the mass and branching ratio are $610<m_U<760$ GeV and $\mathrm{Br}(U\to Zq)>0.3$-$0.45$, respectively.

8 pages, 2 figures

References in corpus (24)

• 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
• Parton distributions for the LHC
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Light custodians in natural composite Higgs models
• Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using $\sqrt{s}=8$ TeV proton--proton collision data
• Towards Closing the Window on Strongly Interacting Dark Matter: Far-Reaching Constraints from Earth's Heat Flow
• Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Search for pair and single production of new heavy quarks that decay to a $Z$ boson and a third-generation quark in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Search for supersymmetry in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $\sqrt{s}=8$ TeV $pp$ collisions with the ATLAS detector
• Analysis of events with $b$-jets and a pair of leptons of the same charge in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Search for physics beyond the standard model in events with two leptons, jets, and missing transverse momentum in pp collisions at sqrt(s) = 8 TeV
• New-physics signals of a model with a vector-singlet up-type quark
• Z-peaked excess from heavy gluon decays to vector-like quarks
• ATLAS Z-peaked excess in MSSM with a light sbottom or stop
• Consistency of the recent ATLAS $Z+E_T^{\mathrm{miss}}$ excess in a simplified GGM model
• The ATLAS Z + MET Excess in the MSSM
• Possible explanation of excess events in the search for jets, missing transverse momentum and a Z boson in pp collisions
• ATLAS Z Excess in Minimal Supersymmetric Standard Model
• Z-peaked excess in goldstini scenarios
• METing SUSY on the Z peak
• Mixed Stops and the ATLAS on-Z Excess
• ATLAS on-Z Excess via gluino-Higgsino-singlino decay chains in the NMSSM
• Testing ATLAS Z+MET Excess with LHC Run 2

Cited by in corpus (6)

• Search for single production of the vector-like top partner at the 14 TeV LHC
• Search for single production of vector-like top partners at the Large Hadron Electron Collider
• Search for single production of the heavy vectorlike $T$ quark with $T\to th$ and $h\to \gamma \gamma$ at the high-luminosity LHC
• Models of 750 GeV quarkonium and the LHC excesses
• Complementarity of Resonant Scalar, Vector-Like Quark and Superpartner Searches in Elucidating New Phenomena
• Aspects of astrophysical particle production and beyond the Standard Model phenomenology