Combination Of The W Boson Polarization Measurements İn Top Quark Decays Using Atlas And Cms Data At Root S=8 Tev
Yükleniyor...
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
CMS Collaboration
Erişim Hakkı
Özet
The combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS ollaborations is presented. The measurements are based on proton-proton collision data produced at the LHC at a centre-of-mass energy of 8 TeV, and corresponding to an integrated luminosity of about 20 fb?1 for each experiment. The measurements used events containing one lepton and having different jet multiplicities in the final state. The results are quoted as fractions of W bosons with longitudinal (F0 ), left-handed (FL), or right-handed (FR) polarizations. The resulting combined measurements of the polarization fractions are F0 = 0.693 ± 0.014 and FL = 0.315 ± 0.011. The fraction FR is calculated from the unitarity constraint to be FR = ?0.008 ± 0.007. These results are in agreement with the standard model predictions at next-to-next-to-leading order in perturbative quantum chromodynamics and represent an improvement in precision of 25 (29)% for F0 (FL) with respect to the most precise single measurement. A limit on anomalous right-handed vector (VR), and left- and right-handed tensor (gL, gR) tWb couplings is set while fixing all others to their standard model values. The allowed regions are [?0.11, 0.16] for VR, [?0.08, 0.05] for gL, and [?0.04, 0.02] for gR, at 95% confidence level. Limits on the corresponding Wilson coefficients are also derived.
Açıklama
Anahtar Kelimeler
Hadron-Hadron scattering (experiments), Top physics
Kaynak
WoS Q Değeri
Q1
Scopus Q Değeri
Q2
Cilt
Sayı
Künye
Journal Of Hıgh Energy Physıcs, 8,(51); 2020
