\begin{document}$\sin^2 \theta _{{\rm{eff}}}^{\ell}$\end{document} at the CERN Large Hadron Collider (LHC). The PDF-induced uncertainty is large in proton-proton collisions at the LHC due to the dilution effect. The measurement of the Drell-Yan forward-backward asymmetry (\begin{document}$A_{\rm FB}$\end{document}) at the LHC can be used to reduce the PDF uncertainty in the \begin{document}$\sin^2 \theta _{{\rm{eff}}}^{\ell}$\end{document} measurement. However, when including the full mass range of lepton pairs in the \begin{document}$A_{\rm FB}$\end{document} data analysis, the correlation between the PDF updating procedure and the \begin{document}$\sin^2 \theta _{{\rm{eff}}}^{\ell}$\end{document} extraction leads to a sizable bias in the obtained \begin{document}$\sin^2 \theta _{{\rm{eff}}}^{\ell}$\end{document} value. From our studies, we find that the bias can be significantly reduced by removing Drell-Yan events with invariant mass around the Z-pole region, while most of the sensitivity in reducing the PDF uncertainty remains. Furthermore, the lepton charge asymmetry in the W boson events as a function of the rapidity of the charged leptons, \begin{document}$A_\pm(\eta_\ell)$\end{document}, is known to be another observable which can be used to reduce the PDF uncertainty in the \begin{document}$\sin^2 \theta _{{\rm{eff}}}^{\ell}$\end{document} measurement. The constraint from \begin{document}$A_\pm(\eta_\ell)$\end{document} is complementary to that from \begin{document}$A_{\rm FB}$\end{document}, and thus no bias affects the \begin{document}$\sin^2 \theta _{{\rm{eff}}}^{\ell}$\end{document} extraction. The studies are performed using the error PDF Updating Method Package (ePump), which is based on Hessian updating methods. In this article, the CT14HERA2 PDF set is used as an example."> Reduction of PDF uncertainty in the measurement of the weak mixing angle at the ATLAS experiment -
  • [1]

    G. Abbiendiet al. (LEP Collaborations ALEPH, DELPHI, L3, and OPAL; SLD Collaboration, LEP Electronweak Working Group; SLD Electroweak and Heavy Flavor Groups), Phys. Rep.427, 257 (2006

  • [2]

    J. C. Collins and D. E. Soper, Phys. Rev. D16, 2219 (1977

  • [3]

    T. Aaltonenet al. (CDF and D0 Collaborations), Phys. Rev. D97, 112007 (2018

  • [4]

    A. M. Sirunyan, A. Tumasyan, W. Adamet al. (CMS Collaboration), Eur. Phys. J. C78, 701 (2018

  • [5]

    R. Aaijet al. (LHCb), JHEP11, 190 (2015), arXiv:1509.07645[hep-ex

  • [6]

    ATLAS public note athttps://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2018-037/

  • [7]

    A. Bodek, J.-Y. Han, A. Khukhunaishviliet al., Eur. Phys. J. C76, 115 (2016

  • [8]

    M. Aaboud, G. Aadet al. (ATLAS collaboration), J. High Energ. Phys.2017, 59 (2017

  • [9]

    R. D. Ballet al. (NNPDF Collaboration), Nucl. Phys. B867, 244 (2013

  • [10]

    S. Dulat, T. J. Hou, J. Gaoet al., Phys. Rev. D93(3), 033006 (2016

  • [11]

    T. J. Hou, S. Dulat, J. Gaoet al., Phys. Rev. D95(3), 034003 (2017

  • [12]

    W. T. Giele and S. Keller, Phys. Rev. D58, 094023 (1998

  • [13]

    R. D. Ball et al. (NNPDF Collaboration), Nucl. Phys. B849, 112 (2011) Erratum: [Nucl. Phys. B854, 926 (2012)] Erratum: [Nucl. Phys. B855, 927 (2012)] doi:10.1016/j.nuclphysb.2011.03.017,10.1016/j.nuclphysb.2011.10.024,10.1016/j.nuclphysb.2011.09.011

  • [14]

    R. D. Ballet al., Nucl. Phys. B855, 608 (2012

  • [15]

    C. Schmidt, J. Pumplin, and C.-P. Yuan, Phys. Rev. D98, 094005 (2018

  • [16]

    H. Paukkunen and P. Zurita, JHEP1412, 100 (2014

  • [17]

    S. Camardaet al. (HERAFitter developers’ Team), Eur. Phys. J. C75(9), 458 (2015

  • [18]

    C. Balázs and C.-P. Yuan, Phys. Rev. D56, 5558-5583 (1997

  • [19]

    F. Landry, R. Brock, P. M. Nadolskyet al., Phys. Rev. D67, 073016 (2003

  • [20]

    P. Sun, J. Isaacson, C. P. Yuanet al., Int. J. Mod. Phys. A33(11), 1841006 (2018

  • [21]

    C. Willis, R. Brock, D. Haydenet al., Phys. Rev. D99(5), 054004 (2019

  • [22]

    G. Aad, B. Abbott, D. C. Abbottet al., Eur. Phys. J. C79, 760 (2019

  • [23]

    J. Pumplin, Phys. Rev. D80, 034002 (2009

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