Search for single production of vector-like quarks decaying into $W(\ell \nu )b$ in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Abstract

A search for single production of a vector-like quark $Q$, which could be either a singlet $T$, with charge $\frac{2}{3}$, or a $Y$ from a $(T,B,Y)$ triplet, with charge $-\frac{4}{3}$, is performed using data from proton-proton collisions at a centre-of-mass energy of 13 TeV. The data correspond to the full integrated luminosity of 140 fb${}^{-1}$ recorded with the ATLAS detector during Run~2 of the Large Hadron Collider. The analysis targets $Q\to Wb$ decays where the $W$ boson decays leptonically. The data are found to be consistent with the expected Standard Model background, so upper limits are set on the cross-section times branching ratio, and on the coupling of the $Q$ to the Standard Model sector for these two benchmark models. Effects of interference with the Standard Model background are taken into account. For the singlet $T$, the 95% confidence level limit on the coupling strength $\kappa$ ranges between 0.22 and 0.52 for masses from 1150 to 2300 GeV. For the $(T,B,Y)$ triplet, the limits on $\kappa$ vary from 0.14 to 0.46 for masses from 1150 to 2600 GeV.

53 pages in total, author list starting page 36, 6 figures, 8 tables, published in JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2018-60

References in corpus (14)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Event generation with SHERPA 1.1
• Herwig++ Physics and Manual
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• Single-top hadroproduction in association with a W boson
• Electroweak gauge boson production at hadron colliders through O(alpha_s^2)
• On the Interpretation of Top Partners Searches
• Stabilizing Electroweak Vacuum in a Vector-like Fermion Model
• New sensitivity of current LHC measurements to vector-like quarks
• Novel Interpretation Strategy for Searches of Singly Produced Vector-like Quarks at the LHC
• Axion framework with color-mediated Dirac neutrino masses