Measurements of top-quark pair to Z-boson cross-section ratios at √s=13 , 8, 7 TeV with the ATLAS detector

Published

Journal Article

© 2017, The Author(s). Ratios of top-quark pair to Z-boson cross sections measured from proton-proton collisions at the LHC centre-of-mass energies of s=13 TeV, 8 TeV, and 7 TeV are presented by the ATLAS Collaboration. Single ratios, at a given s for the two processes and at different s for each process, as well as double ratios of the two processes at different s, are evaluated. The ratios are constructed using previously published ATLAS measurements of the tt¯ 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, μ at 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 s 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.[Figure not available: see fulltext.]

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Cited Authors

  • Aaboud, M; Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; Abidi, SH; AbouZeid, OS; Abraham, NL; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, BS; Adachi, S; Adamczyk, L; Adams, DL; Adelman, J; Adye, T; Affolder, AA; Agatonovic-Jovin, T; Agheorghiesei, C; Aguilar-Saavedra, JA; Ahlen, SP; Ahmadov, F; Aielli, G; Akatsuka, S; Akerstedt, H; Åkesson, TPA; Akimov, AV; Alberghi, GL; Albert, J; Alconada Verzini, MJ; Aleksa, M; Aleksandrov, IN; Alexa, C; Alexander, G; Alexopoulos, T; Alhroob, M; Ali, B; Aliev, M; Alimonti, G; Alison, J; Alkire, SP; Allbrooke, BMM; Allen, BW; Allport, PP; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Alshehri, AA; Alstaty, M; Alvarez Gonzalez, B; Álvarez Piqueras, D; Alviggi, MG; Amadio, BT; Amaral Coutinho, Y; Amelung, C; Amidei, D; Amor Dos Santos, SP; Amorim, A; Amoroso, S; Amundsen, G; Anastopoulos, C; Ancu, LS; Andari, N; Andeen, T; Anders, CF; Anders, JK; Anderson, KJ; Andreazza, A; Andrei, V; Angelidakis, S; Angelozzi, I; Angerami, A; Anghinolfi, F; Anisenkov, AV; Anjos, N; Annovi, A; Antel, C; Antonelli, M; Antonov, A; Antrim, DJ; Anulli, F; Aoki, M; Aperio Bella, L; Arabidze, G; Arai, Y; Araque, JP; Araujo Ferraz, V; Arce, ATH; Arduh, FA; Arguin, JF; Argyropoulos, S; Arik, M; Armbruster, AJ; Armitage, LJ; Arnaez, O

Published Date

  • February 1, 2017

Published In

Volume / Issue

  • 2017 / 2

Electronic International Standard Serial Number (EISSN)

  • 1029-8479

International Standard Serial Number (ISSN)

  • 1126-6708

Digital Object Identifier (DOI)

  • 10.1007/JHEP02(2017)117

Citation Source

  • Scopus