The W boson helicity fractions from top quark decays in tt‾ events are measured using data from proton–proton collisions at a centre-of-mass energy of 8TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8fb−1. Events are reconstructed with either one muon or one electron, along with four jets in the final state, with two of the jets being identified as originating from b quarks. The measured helicity fractions from both channels are combined, yielding F0=0.681±0.012(stat)±0.023(syst), FL=0.323±0.008(stat)±0.014(syst), and FR=−0.004±0.005(stat)±0.014(syst) for the longitudinal, left-, and right-handed components of the helicity, respectively. These measurements of the W boson helicity fractions are the most accurate to date and they agree with the predictions from the standard model.

Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Asilar, E., Bergauer, T., et al. (2016). Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton + jets final states produced in pp collisions at s=8TeV. PHYSICS LETTERS. SECTION B, 762, 512-534 [10.1016/j.physletb.2016.10.007].

Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton + jets final states produced in pp collisions at s=8TeV

BRIANZA, LUCA;DINARDO, MAURO EMANUELE;FIORENDI, SARA;GENNAI, STEFANO;GHEZZI, ALESSIO;GOVONI, PIETRO;MANZONI, RICCARDO ANDREA;MARZOCCHI, BADDER;MORONI, LUIGI;PAGANONI, MARCO;PIGAZZINI, SIMONE;RAGAZZI, STEFANO;TABARELLI DE FATIS, TOMMASO;De Guio, F;Lucchini, M;
2016

Abstract

The W boson helicity fractions from top quark decays in tt‾ events are measured using data from proton–proton collisions at a centre-of-mass energy of 8TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8fb−1. Events are reconstructed with either one muon or one electron, along with four jets in the final state, with two of the jets being identified as originating from b quarks. The measured helicity fractions from both channels are combined, yielding F0=0.681±0.012(stat)±0.023(syst), FL=0.323±0.008(stat)±0.014(syst), and FR=−0.004±0.005(stat)±0.014(syst) for the longitudinal, left-, and right-handed components of the helicity, respectively. These measurements of the W boson helicity fractions are the most accurate to date and they agree with the predictions from the standard model.
Articolo in rivista - Articolo scientifico
Anomalous couplings; CMS; Helicity; Physics; Top;
Anomalous couplings; CMS; Helicity; Physics; Top; Nuclear and High Energy Physics
English
2016
762
512
534
none
Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Asilar, E., Bergauer, T., et al. (2016). Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton + jets final states produced in pp collisions at s=8TeV. PHYSICS LETTERS. SECTION B, 762, 512-534 [10.1016/j.physletb.2016.10.007].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/140771
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