TY  - JOUR
AU  - ATLAS Collaboration (Aaboud, M. et al
AU  - Alvarez Piqueras, D.
AU  - Barranco Navarro, L.
AU  - Cabrera Urban, S.
AU  - Castillo Gimenez, V.
AU  - Cerda Alberich, L.
AU  - Costa, M. J.
AU  - Fernandez Martinez, P.
AU  - Ferrer, A.
AU  - Fiorini, L.
AU  - Fuster, J.
AU  - Garcia, C.
AU  - Garcia Navarro, J. E.
AU  - Gonzalez de la Hoz, S.
AU  - Higon-Rodriguez, E.
AU  - Jimenez Pena, J.
AU  - Lacasta, C.
AU  - Mamuzic, J.
AU  - Marti-Garcia, S.
AU  - Melini, D.
AU  - Mitsou, V. A.
AU  - Pedraza Lopez, S.
AU  - Rodriguez Rodriguez, D.
AU  - Romero Adam, E.
AU  - Ros, E.
AU  - Salt, J.
AU  - Sanchez Martinez, V.
AU  - Soldevila, U.
AU  - Sanchez, J.
AU  - Valero, A.
AU  - Valls Ferrer, J. A.
AU  - Vos, M.
PY  - 2017
DA  - 2017//
TI  - Measurements of top-quark pair to Z-boson cross-section ratios at root s=13, 8, 7 TeV with the ATLAS detector
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 117
EP  - 54pp
VL  - 02
IS  - 2
PB  - Springer
KW  - Hadron-Hadron scattering (experiments)
AB  - Ratios of top-quark pair to Z-boson cross sections measured from proton-proton-collisions at the LHC centre-of-mass energies of root S = 13 TeV, 8 TeV, and 7 TeV are presented by the ATLAS Collaboration. Single ratios, at a given root S for the two processes and at different root S , for each process, as well as double ratios of the two processes at different root S , are evaluated. The ratios are constructed using previously published ATLAS measurements of the t (t) over bar and Z-boson production cross sections, corrected to a common phase space where required, and a new analysis of Z -> l(+)l(-) where l = e, μat root S = 13 TeV performed with data collected in 2015 with an integrated luminosity of 3.2 fb(-1). Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the Z -> e (+) e (-) and the Z -> μ(+) μ(-) channels for each value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-x values near 0.1 and the light-quark sea for x < 0.02.
SN  - 1029-8479
UR  - http://arxiv.org/abs/1612.03636
UR  - https://doi.org/10.1007/JHEP02(2017)117
DO  - 10.1007/JHEP02(2017)117
LA  - English
N1  - WOS:000395022700001
ID  - ATLASCollaborationAaboud_etal2017
ER  -