The W-boson helicity fractions in top-quark decays are measured with t (t) over bar 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 fb(-1). The measured fractions of longitudinal, left-, and right-handed helicity are F-0 = 0.682 +/- 0.030 (stat.) +/- 0.033 (syst.), F-L = 0.310 +/- 0.022 (stat.) +/- 0.022 (syst.), and F-R = 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 g(L), g(R) are also derived.

Measurement of the W-boson helicity in top-quark decays from t(t)over-bar production in lepton plus jets events in pp collisions at root s=7 TeV

BISELLO, DARIO;CARLIN, ROBERTO;GALANTI, MARIO;GASPARINI, FABRIZIO;GASPARINI, UGO;GIUBILATO, PIERO;GOZZELINO, ANDREA;MARGONI, MARTINO;MENEGUZZO, ANNA TERESA;PAZZINI, JACOPO;POZZOBON, NICOLA;RONCHESE, PAOLO;SIMONETTO, FRANCO;TOSI, MIA;A. Triossi;ZOTTO, PIERLUIGI;ZUCCHETTA, ALBERTO;ZUMERLE, GIANNI;M. Grassi;ROSSIN, ROBERTO;A. Gaz;M. Zanetti;
2013

Abstract

The W-boson helicity fractions in top-quark decays are measured with t (t) over bar 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 fb(-1). The measured fractions of longitudinal, left-, and right-handed helicity are F-0 = 0.682 +/- 0.030 (stat.) +/- 0.033 (syst.), F-L = 0.310 +/- 0.022 (stat.) +/- 0.022 (syst.), and F-R = 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 g(L), g(R) are also derived.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2799695
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 36
  • ???jsp.display-item.citation.isi??? 48
  • OpenAlex ND
social impact