Measurements of charge and CP asymmetries in $b$-hadron decays using top-quark events collected by the ATLAS detector in $pp$ collisions at $\sqrt{s}=8$ TeV

Abstract

Same- and opposite-sign charge asymmetries are measured in lepton+jets $t\bar{t}$ events in which a $b$-hadron decays semileptonically to a soft muon, using data corresponding to an integrated luminosity of 20.3 fb${}^{-1}$ from proton--proton collisions at a centre-of-mass energy of $\sqrt{s}=8$ TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. The charge asymmetries are based on the charge of the lepton from the top-quark decay and the charge of the soft muon from the semileptonic decay of a $b$-hadron and are measured in a fiducial region corresponding to the experimental acceptance. Four CP asymmetries (one mixing and three direct) are measured and are found to be compatible with zero and consistent with the Standard Model.

arXiv comment47 pages in total, author list starting page 31, 4 figures, 7 tables, submitted to JHEP, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2016-07/

References in corpus (79)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The anti-k_t jet clustering algorithm
• A Brief Introduction to PYTHIA 8.1
• Parton distributions for the LHC
• New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
• Big-Bang Nucleosynthesis
• A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
• A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• New parton distributions for collider physics
• HERWIG 6.5: an event generator for Hadron Emission Reactions With Interfering Gluons (including supersymmetric processes)
• Parton distributions with LHC data
• ALPGEN, a generator for hard multiparton processes in hadronic collisions
• Matching NLO QCD computations and parton shower simulations
• The ATLAS Simulation Infrastructure
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of summer 2016
• Implications of CTEQ global analysis for collider observables
• Top++: a program for the calculation of the top-pair cross-section at hadron colliders
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• An update on vector boson pair production at hadron colliders
• Tuning Monte Carlo Generators: The Perugia Tunes
• Performance of the ATLAS Trigger System in 2015
• Vector boson pair production at the LHC
• 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-
• Single-top hadroproduction in association with a W boson
• Percent level precision physics at the Tevatron: first genuine NNLO QCD corrections to q qbar -> t tbar + X
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• Electroweak gauge boson production at hadron colliders through O(alpha_s^2)
• Observation of Large CP Violation in the Neutral B Meson System
• NNLO corrections to top-pair production at hadron colliders: the all-fermionic scattering channels
• NLO single-top production matched with shower in POWHEG: s- and t-channel contributions
• NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction
• Observation of CP violation in the B^0 meson system
• Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production
• Matching NLO QCD and parton showers in heavy flavour production
• The CT10 NNLO Global Analysis of QCD
• NNLL resummation for s-channel single top quark production
• Performance of pile-up mitigation techniques for jets in $pp$ collisions at $\sqrt{s}=8$ TeV using the ATLAS detector
• The PDF4LHC Working Group Interim Recommendations
• Hadronic top-quark pair production with NNLL threshold resummation
• Jet energy measurement with the ATLAS detector in proton-proton collisions at sqrt(s) = 7 TeV
• Luminosity determination in pp collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector at the LHC
• Performance of $b$-Jet Identification in the ATLAS Experiment
• Observation of Direct CP Violation in K_{S,L} to ππDecays
• Jet energy measurement and its systematic uncertainty in proton-proton collisions at $\sqrt{s}=7$ TeV with the ATLAS detector
• Performance of the ATLAS Trigger System in 2010
• Electron and photon energy calibration with the ATLAS detector using LHC Run 1 data
• A new measurement of direct CP violation in two pion decays of the neutral kaon
• Multijet matrix elements and shower evolution in hadronic collisions: W b bbar + n jets as a case study
• Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton-proton collision data
• Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton-proton collision data
• Jet energy resolution in proton-proton collisions at sqrt(s) = 7 TeV recorded in 2010 with the ATLAS detector
• Next-to-leading order QCD predictions for W+2j and Z+2j production at the CERN LHC
• Direct CP Violating Asymmetry in B0 -> K+pi- Decays
• Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays
• First observation of CP violation in the decays of Bs mesons
• Measurement of the $t\bar{t}$ production cross-section using $e\mu$ events with $b$-tagged jets in $pp$ collisions at $\sqrt{s}=7$ and 8 TeV with the ATLAS detector
• Evidence for direct CP violation in the decay B->D(*)K, D->KsPi+Pi- and measurement of the CKM phase phi3
• Measurement of the top quark pair production cross-section with ATLAS in the single lepton channel
• A likelihood-based reconstruction algorithm for top-quark pairs and the KLFitter framework
• Testing New Indirect CP Violation
• Muon reconstruction efficiency and momentum resolution of the ATLAS experiment in proton-proton collisions at $\sqrt{s}$=7 TeV in 2010
• On Indirect CP Violation and Implications for D0-\overline{D0} and Bs -\overline{Bs} mixing
• Study of CP-violating charge asymmetries of single muons and like-sign dimuons in p pbar collisions
• Measurement of the semileptonic $CP$ asymmetry in $B^0-\overline{B}{}^0$ mixing
• Measurement of the $t\bar{t}$ production cross-section as a function of jet multiplicity and jet transverse momentum in 7 TeV proton-proton collisions with the ATLAS detector
• Measurement of CP observables in B+- --> D_CP K+- decays and constraints on the CKM angle gamma
• Measurement of the t t-bar production cross section in the all-jets final state in pp collisions at sqrt(s) = 8 TeV
• Measurement of the $CP$ asymmetry in $B_s^0-\overline{B}{}_s^0$ mixing
• Measurement of the top pair production cross-section in 8 TeV proton-proton collisions using kinematic information in the lepton+jets final state with ATLAS
• CP violation in the B system
• Measurement of the ttbar production cross section in pp collisions at sqrt(s) = 8 TeV in dilepton final states containing one tau lepton
• Study of CP asymmetry in B0-B0bar mixing with inclusive dilepton events
• Top B Physics at the LHC
• Second order direct CP asymmetry in B_(s) -> X l nu
• On the origin of the D0 like-sign dimuon charge asymmetry

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• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of summer 2016
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2018
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2021
• CP violation in the B system
• Top-Quark Physics: Status and Prospects
• Non-Standard Interactions and Prospects for Studying Standard Parameter Degeneracies in DUNE and T2HKK
• Probing the top-quark width using the charge identification of $b$ jets
• T-odd anomalous interactions of the top-quark at the Large Hadron Collider
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