Search for pair production of heavy vector-like quarks decaying into hadronic final states in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Abstract

A search is presented for the pair production of heavy vector-like quarks, $T\bar{T}$ or $B\bar{B}$, that decay into final states with jets and no reconstructed leptons. Jets in the final state are classified using a deep neural network as arising from hadronically decaying $W/Z$ bosons, Higgs bosons, top quarks, or background. The analysis uses data from the ATLAS experiment corresponding to 36.1 fb${}^{-1}$ of proton-proton collisions with a center-of-mass energy of $\sqrt{s}=13$ TeV delivered by the Large Hadron Collider in 2015 and 2016. No significant deviation from the Standard Model expectation is observed. Results are interpreted assuming the vector-like quarks decay into a Standard Model boson and a third-generation-quark, $T\to Wb,Ht,Zt$ or $B\to Wt,Hb,Zb$, for a variety of branching ratios. At 95% confidence level, the observed (expected) lower limit on the vector-like $B$-quark mass for a weak-isospin doublet ($B,Y$) is 950 (890) GeV, and the lower limits on the masses for the pure decays $B\to Hb$ and $T\to Ht$, where these results are strongest, are 1010 (970) GeV and 1010 (1010) GeV, respectively.

51 pages in total, author list starts at page 35, 14 figures, 3 tables, submitted to Physical Review D. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2017-14/

References in corpus (15)

• Batch Normalization: Accelerating Deep Network Training by Reducing Internal Covariate Shift
• Deep Learning in Neural Networks: An Overview
• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• 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
• New parton distributions for collider physics
• FeynRules - Feynman rules made easy
• Single-top Wt-channel production matched with parton showers using the POWHEG method
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• Luminosity determination in pp collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector at the LHC
• Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method
• 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 pair production of vector-like T and B quarks in single-lepton final states using boosted jet substructure in proton-proton collisions at sqrt(s) = 13 TeV

Cited by in corpus (38)

• Combination of the searches for pair-produced vector-like partners of the third-generation quarks at $\sqrt{s}=$ 13 TeV with the ATLAS detector
• Search for pair production of vector-like quarks in the fully hadronic final state
• DisCo Fever: Robust Networks Through Distance Correlation
• Prospects for vectorlike leptons at future proton-proton colliders
• Next-to-leading-order predictions for single vector-like quark production at the LHC
• Exotic decays of top partners: mind the search gap
• New sensitivity of current LHC measurements to vector-like quarks
• A search for bottom-type, vector-like quark pair production in a fully hadronic final state in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Novel Interpretation Strategy for Searches of Singly Produced Vector-like Quarks at the LHC
• Search for large missing transverse momentum in association with one top-quark in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Exotic Vector-Like Quark Phenomenology in the Minimal Linear $\sigma$ Model
• Continuum Naturalness
• Search for pair-produced vector-like top and bottom partners in events with large missing transverse momentum in pp collisions with the ATLAS detector
• Search for single production of a vector-like T quark decaying to a top quark and a Z boson in the final state with jets and missing transverse momentum at $\sqrt{s}=$ 13 TeV
• Phenomenology of unusual top partners in composite Higgs models
• Hunting for top partner with a new signature at the LHC
• The $W\gamma$ decay of the elusive charged Higgs boson in the two-Higgs-doublet model with vectorlike fermions
• Disentangling new physics effects on non-resonant Higgs boson pair production from gluon fusion
• Vector-like quarks: status and new directions at the LHC
• Probing Charged Higgs Bosons in the 2-Higgs Doublet Model Type-II with Vector-Like Quarks
• High-quality axions in solutions to the $\mu$ problem
• Exploring maverick top partner decays at the LHC
• From the Bottom to the Top -- Reconstruction of $t\bar{t}$ Events with Deep Learning
• Search for a heavy resonance decaying to a top quark and a vector-like top quark in the lepton+jets final state in pp collisions at $\sqrt{s}=$ 13 TeV
• Single production of vectorlike $B$ quarks at the CLIC
• Search for singly produced vector-like top partners in multilepton final states with 139 ${\mathrm{fb}}^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for production of a single vector-like quark decaying to tH or tZ in the all-hadronic final state in pp collisions at $\sqrt{s}$ = 13 TeV
• Search for single production of vectorlike $B$-quarks at the LHC
• Single production of vector-like $T$ quark at future high-energy linear $e^{+}{e}^{-}$ collider
• Perspectives and Outlook from HEP Window on the Universe
• A search for bottom-type vector-like quark pair production in dileptonic and fully hadronic final states in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Les Houches guide to reusable ML models in LHC analyses
• Down type iso-singlet quarks at the HL-LHC and FCC-hh
• Combination of searches for singly produced vector-like top quarks in pp collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Vector-like Quark Interpretation of Excess in Higgs Signal Strength
• Searching for single production of vectorlike quarks decaying into Wb at a future muon-proton collider
• LHC probes of the 10 TeV scale
• Vector-Like top quark production via a chromo-magnetic moment at the LHC