4 research outputs found
Measurement of the CP-violating phase ϕs in Bs0→J/ψϕ decays in ATLAS at 13 TeV
No full text© 2021, The Author(s).A measurement of the Bs0→J/ψϕ decay parameters using 80.5fb-1 of integrated luminosity collected with the ATLAS detector from 13 Te proton–proton collisions at the LHC is presented. The measured parameters include the CP-violating phase ϕs, the width difference Δ Γ s between the Bs0 meson mass eigenstates and the average decay width Γ s. The values measured for the physical parameters are combined with those from 19.2fb-1 of 7 and 8 Te data, leading to the following: ϕs=-0.087±0.036(stat.)±0.021(syst.)radΔΓs=0.0657±0.0043(stat.)±0.0037(syst.)ps-1Γs=0.6703±0.0014(stat.)±0.0018(syst.)ps-1Results for ϕs and Δ Γ s are also presented as 68% confidence level contours in the ϕs–Δ Γ s plane. Furthermore the transversity amplitudes and corresponding strong phases are measured. ϕs and Δ Γ s measurements are in agreement with the Standard Model predictions.ANIDBSF-NSFCEA-DRFCantons of Bern and GenevaCzech RepublicDNSRCEU-ESFGenT Programmes Generalitat Valenciana, SpainIRFULa Caixa Banking FoundationMES of RussiaMESTDMIZŠMSMTMSSRPROMETEORGCVSC CRWallenberg FoundationNSFDOEAvH FoundationCOLCIENCIASCANARIEMarie Skłodowska-Curie ActionsANASCERNGIFGöran Gustafssons StiftelseNSERCNRCCFISTFCLeverhulme TrustRoyal SocietyERCCOSTARCNRFDSTSERIHGFDFGANRJSPSMEXTSNSFDNRFFAPESPNSFCFCTBMBFCASFWFGeneralitat de CatalunyaANPCyTNWOBMWFWGSRTCNPqJINRBenoziyo Center, IsraelISFINFNNCNARRSMNiSWMOSTMICINNCNRSTHorizon 2020BCKDFERDFBeijing Municipal Science & Technology CommissionRussian FederationNRC KIIVAD
Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector
No full text868 pages, 295 figures, 248 tables and 1642 citations. Working Group web page: https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWGThis Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond
Measurement of differential cross-sections of a single top quark produced in association with a W boson at √s=13TeV with ATLAS
No full text© 2018, CERN for the benefit of the ATLAS collaboration.The differential cross-section for the production of a W boson in association with a top quark is measured for several particle-level observables. The measurements are performed using 36.1fb-1 of pp collision data collected with the ATLAS detector at the LHC in 2015 and 2016. Differential cross-sections are measured in a fiducial phase space defined by the presence of two charged leptons and exactly one jet matched to a b-hadron, and are normalised with the fiducial cross-section. Results are found to be in good agreement with predictions from several Monte Carlo event generators
Direct top-quark decay width measurement in the tt¯ lepton+jets channel at √s=8TeV with the ATLAS experiment
No full text© 2018, CERN for the benefit of the ATLAS collaboration.This paper presents a direct measurement of the decay width of the top quark using tt¯ events in the lepton+jets final state. The data sample was collected by the ATLAS detector at the LHC in proton–proton collisions at a centre-of-mass energy of 8 TeV and corresponds to an integrated luminosity of 20.2 fb- 1. The decay width of the top quark is measured using a template fit to distributions of kinematic observables associated with the hadronically and semileptonically decaying top quarks. The result, Γt=1.76±0.33(stat.)-0.68+0.79(syst.)GeV for a top-quark mass of 172.5 GeV, is consistent with the prediction of the Standard Model
