TY - JOUR
T1 - Combination of the W boson polarization measurements in top quark decays using ATLAS and CMS data at √s = 8 TeV
AU - ATLAS Collaboration
AU - The CMS Collaboration
AU - Bracinik, Juraj
AU - Briglin, Daniel
AU - Charlton, David
AU - Chisholm, Andrew
AU - Freeman, Patrick
AU - Gonella, Laura
AU - Gonnella, Francesco
AU - Gorasia, Nandish
AU - Hawkes, Chris
AU - Kempster, Jacob
AU - Kendrick, James
AU - Lindon, Lindon
AU - Neep, Thomas
AU - Newman, Paul
AU - Nikolopoulos, Konstantinos
AU - Reynolds, Elliot
AU - Thomas, Jurgen
AU - Vallance, Robert
AU - Virdee, Gov
AU - Watson, Alan
AU - Watson, Miriam
PY - 2020/8/12
Y1 - 2020/8/12
N2 - The combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS collaborations 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.
AB - The combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS collaborations 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.
KW - Hadron-Hadron scattering (experiments)
KW - Top physics
U2 - 10.1007/JHEP08(2020)051
DO - 10.1007/JHEP08(2020)051
M3 - Article
SN - 1126-6708
VL - 2020
JO - JHEP
JF - JHEP
IS - 8
M1 - 51
ER -