Münster 2017 – wissenschaftliches Programm
T 6.2: Vortrag
Montag, 27. März 2017, 17:00–17:15, VSH 10
Measurements of top-pair to Z-boson cross section ratios at center-of-mass energies of √s=13,8,7 TeV with the ATLAS detector and evaluation of measured cross sections constraints on PDFs and strong coupling constant. — •Artur Trofymov — DESY, Hamburg, Germany
Ratios of top-quark pair to Z-boson production (Z → ℓ+ ℓ− where ℓ = e, µ) cross sections at center-of-mass energies of √s = 13, 8, 7 TeV are measured using data recorded by the ATLAS experiment at the LHC. Data at √s = 13 TeV for both analyses are collected in 2015 with total integrated luminosity of 3.2 fb−1. Previously published Z-boson and top-quark pair cross sections measured at √s = 8 and 7 TeV are corrected to phase space of measurements at √s = 13 TeV and used for the ratios calculation. Single cross section ratios at a given √s for the two processes and same process at different √s, as well as double ratios of two processes at different √s, are evaluated. The ratio results are compared to the predictions calculated at next-to-next-to-leading order for different parton distribution functions (PDFs). The correlated cross section measurements are used to obtain constraints on PDFs and the strong coupling constant αs.