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arXiv · 1805.09239

Neutral Current Forward-Backward Asymmetry: from $θ_W$ to PDF Determinations

Elena Accomando·Juri Fiaschi·Francesco Hautmann·Stefano Moretti
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Abstract

Measurements of the forward-backward asymmetry in neutral-current Drell-Yan di-lepton production have primarily been used for determinations of the weak mixing angle $θ_W$. We observe that, unlike the case of Run-I of the Large Hadron Collider (LHC Run-I), for the first time at the LHC Run-II the reconstructed forward-backward asymmetry has the capability of placing useful constraints on the determination of the parton distribution functions (PDFs). By examining the statistical and the PDF uncertainties on the reconstructed forward-backward asymmetry, we investigate its potential for disentangling the flavour content of quark and antiquark PDFs. Access to the valence/sea $u$-quark and to the sea up-type antiquark PDFs, in particular, may be gained by the appropriate use of selection cuts in the rapidity of the emerging lepton pair in regions both near the $Z$-boson peak and away from it, in a manner complementary, though more indirect, to the case of the charged-current asymmetry. We study the extension of these results for the planned high-luminosity (HL) LHC.

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Elena Accomando, Juri Fiaschi, Francesco Hautmann, Stefano Moretti. 2019-03-18. Neutral Current Forward-Backward Asymmetry: from $θ_W$ to PDF Determinations. https://doi.org/10.1140/epjc%2Fs10052-018-6120-6

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