Measurement of the W-boson helicity in top-quark decays from ttbar production in lepton+jets events in pp collisions at sqrt(s) = 7 TeV

Abstract

The W-boson helicity fractions in top-quark decays are measured with ttbar events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 inverse femtobarns. The measured fractions of longitudinal, left-, and right-handed helicity are F0 = 0.682 +/- 0.030 (stat.) +/- 0.033 (syst.), FL = 0.310 +/- 0.022 (stat.) +/- 0.022 (syst.), and FR = 0.008 +/- 0.012 (stat.) +/- 0.014 (syst.), consistent with the standard model predictions. The measured fractions are used to probe the existence of anomalous Wtb couplings. Exclusion limits on the real components of the anomalous couplings gL, gR are also derived.

Replaced with published version. Added journal reference and DOI

References in corpus (14)

• PYTHIA 6.4 Physics and Manual
• Parton distributions for the LHC
• New parton distributions for collider physics
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order
• Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production
• The PDF4LHC Working Group Interim Recommendations
• NLO vector-boson production matched with shower in POWHEG
• Measurement of the single-top-quark t-channel cross section in pp collisions at sqrt(s) = 7 TeV
• A minimal set of top-Higgs anomalous couplings
• Single top quark production at LHC with anomalous Wtb couplings
• Probing anomalous Wtb couplings in top pair decays
• Evidence for associated production of a single top quark and W boson in pp collisions at sqrt(s) = 7 TeV
• Measurement of the W boson polarization in top quark decays with the ATLAS detector

Cited by in corpus (34)

• Constraining the top-Higgs sector of the Standard Model Effective Field Theory
• Constraining top quark effective theory in the LHC Run II era
• Identification techniques for highly boosted W bosons that decay into hadrons
• Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at sqrt(s) = 7 and 8 TeV
• Global and optimal probes for the top-quark effective field theory at future lepton colliders
• Breaking down the entire W boson spin observables from its decay
• Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton + jets final states produced in pp collisions at sqrt(s) = 8 TeV
• Measurement of the W boson helicity in events with a single reconstructed top quark in pp collisions at sqrt(s) = 8 TeV
• Search for anomalous couplings in the $Wtb$ vertex from the measurement of double differential angular decay rates of single top quarks produced in the $t$-channel with the ATLAS detector
• Studying the $Wtb$ vertex structure using recent LHC results
• Top-Quark Physics: Status and Prospects
• Combination of the W boson polarization measurements in top quark decays using ATLAS and CMS data at $\sqrt{s}=$ 8 TeV
• New limits on anomalous contributions to the $Wtb$ vertex
• Better Hadronic Top Quark Polarimetry
• Top physics at the LHC
• Probing anomalous $Wtb$ couplings at the LHC in single top quark production through $t$-channel
• CP-violating top quark couplings at future linear $e^{+}{e}^{-}$ colliders
• Top-quark physics at the Large Hadron Collider
• Analysis of the $Wtb$ vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the $t$-channel at $\sqrt{s}$ = 8 TeV with the ATLAS detector
• Correlating uncertainties in global analyses within SMEFT matters
• Top quark anomalous tensor couplings in the two-Higgs-doublet models
• $tbW$ Anomalous Couplings in the Two Higgs Doublet Model
• On the Trail of the Higgs Boson
• The Higgs boson and the physics of $WW$ scattering before and after Higgs discovery
• Electroweak Top Couplings, Partial Compositeness and Top Partner Searches
• Properties of the Top Quark
• Effective approach to top-quark decay and FCNC processes at NLO accuracy
• Single Top Quark Production with and without a Higgs Boson
• Top quark effective couplings from top-pair tagged photoproduction in $p{e}^{-}$ collisions
• Top quark physics in the Large Hadron Collider era
• Staying on Top of SMEFT-Likelihood Analyses
• Limits on anomalous top quark gauge couplings from Tevatron and LHC data
• A Global Analysis of the Standard Model Effective Field Theory in the Production and Decay Channels of a Single Top Quark
• Measurement of the W boson helicity using top pair events at $\sqrt{s}$ = 8 TeV with the CMS detector