Search for flavour-changing neutral-current couplings between the top quark and the Higgs boson in multi-lepton final states in 13 TeV pp collisions with the ATLAS detector
department or school: Science, Faculty of
department or school: TRIUMF
department or school: Non UBC
department or school: Physics and Astronomy, Department of
data provider: DSpace
identifier citation: The European Physical Journal C. 2024 Jul 29;84(7):757
rights copyright: The Author(s)
creator: ATLAS Collaboration
issued: 2024-10-24T22:35:54Z
issued: 2024-07-29
description: A search is presented for flavour-changing neutralcurrent interactions involving the top quark, the Higgs boson and an up-type quark (q = u, c) with the ATLAS detector at the Large Hadron Collider. The analysis considers leptonic decays of the top quark along with Higgs boson decays into two W bosons, two Z bosons or a τ +τ − pair. It focuses on final states containing either two leptons (electrons or muons) of the same charge or three leptons. The considered processes are tt ¯and Ht production. For the tt ¯production, one top quark decays via t → H q. The proton–proton collision data set analysed amounts to (140 fb−1) at ( √s = 13 TeV). No significant excess beyond Standard Model expectations is observed and upper limits are set on the t → H q branching ratios at 95 % confidence level, amounting to observed (expected) limits of B(t → H u) < 2.8 (3.0) × 10−4 and B(t → Hc) < 3.3 (3.8) × 10−4. Combining this search with other searches fortHq flavour-changing neutral-current interactions previously conducted by ATLAS, considering H → bb¯ and H → γ γ decays, as well as H → τ +τ − decays with one or two hadronically decaying τ -leptons, yields observed (expected) upper limits on the branching ratios of B(t → H u) < 2.6 (1.8)×10−4 and B(t → Hc) < 3.4 (2.3) × 10−4.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/89514
note: Eur. Phys. J. C (2024) 84:757 https://doi.org/10.1140/epjc/s10052-024-12994-1Regular Article - Experimental PhysicsSearch for flavour-changing neutral-current couplings betweenthe top quark and the Higgs boson in multi-lepton final statesin 13 TeV pp collisions with the ATLAS detectorATLAS CollaborationCERN, 1211 Geneva 23, SwitzerlandReceived: 4 April 2024 / Accepted: 7 June 2024© CERN for the benefit of the ATLAS Collaboration 2024Abstract A search is presented for flavour-changing neutral-current interactions involving the top quark, the Higgs bosonand an up-type quark (q = u, c) with the ATLAS detectorat the Large Hadron Collider. The analysis considers lep-tonic decays of the top quark along with Higgs boson decaysinto two W bosons, two Z bosons or a τ+τ− pair. It focuseson final states containing either two leptons (electrons ormuons) of the same charge or three leptons. The consideredprocesses are t t¯ and Ht production. For the t t¯ production, onetop quark decays via t → Hq. The proton–proton collisiondata set analysed amounts to (140 fb−1) at (√s = 13 TeV).No significant excess beyond Standard Model expectationsis observed and upper limits are set on the t → Hq branch-ing ratios at 95 % confidence level, amounting to observed(expected) limits of B(t → Hu) < 2.8 (3.0) × 10−4 andB(t → Hc) < 3.3 (3.8) × 10−4. Combining this searchwith other searches for t Hq flavour-changing neutral-currentinteractions previously conducted by ATLAS, consideringH → bb¯ and H → γ γ decays, as well as H → τ+τ−decays with one or two hadronically decaying τ -leptons,yields observed (expected) upper limits on the branchingratios of B(t → Hu) < 2.6 (1.8)×10−4 and B(t → Hc) <3.4 (2.3) × 10−4.Contents1 Introduction . . . . . . . . . . . . . . . . . . . . . .2 The ATLAS detector . . . . . . . . . . . . . . . . . .3 Samples of data and simulated events . . . . . . . . .3.1 Simulation of t Hq FCNC signal samples . . . . .3.2 Simulation of background processes . . . . . . .4 Object recons…
has type: Article
is shown at: 10.14288/1.0447111
language: eng
peer review status: Reviewed
provider: Vancouver : University of British Columbia Library
publisher: Springer Berlin Heidelberg
publisher DOI: 10.1140/epjc/s10052-024-12994-1
rights: Attribution 4.0 International (CC BY 4.0)
rights URI: http://creativecommons.org/licenses/by/4.0/
scholar level: Faculty
type: Text
identifier URI: http://hdl.handle.net/2429/89514