%AYang, Siqi%AFu, Yao%ALiu, Minghui%AZhang, Renyou%AHou, Tie-Jiun%AWang, Chen%AYin, Hang%AHan, Liang%AYuan, C.%BJournal Name: The European Physical Journal C; Journal Volume: 82; Journal Issue: 4; Related Information: CHORUS Timestamp: 2022-05-23 14:04:33
%D2022%ISpringer Science + Business Media; None
%JJournal Name: The European Physical Journal C; Journal Volume: 82; Journal Issue: 4; Related Information: CHORUS Timestamp: 2022-05-23 14:04:33
%K
%MOSTI ID: 10367820
%PMedium: X
%TReduction of the electroweak correlation in the PDF updating by using the forward–backward asymmetry of Drell–Yan process
%XAbstract
We propose a new observable for the measurement of the forward–backward asymmetry$$(A_{FB})$$$\left({A}_{\mathrm{FB}}\right)$in Drell–Yan lepton production. At hadron colliders, the$$A_{FB}$$${A}_{\mathrm{FB}}$distribution is sensitive to both the electroweak (EW) fundamental parameter$$\sin ^{2} \theta _{W}$$${sin}^{2}{\theta}_{W}$, the weak mixing angle, and the parton distribution functions (PDFs). Hence, the determination of$$\sin ^{2} \theta _{W}$$${sin}^{2}{\theta}_{W}$and the updating of PDFs by directly using the same$$A_{FB}$$${A}_{\mathrm{FB}}$spectrum are strongly correlated. This correlation would introduce large bias or uncertainty into both precise measurements of EW and PDF sectors. In this article, we show that the sensitivity of$$A_{FB}$$${A}_{\mathrm{FB}}$on$$\sin ^{2} \theta _{W}$$${sin}^{2}{\theta}_{W}$is dominated by its average value around theZpole region, while the shape (or gradient) of the$$A_{FB}$$${A}_{\mathrm{FB}}$spectrum is insensitive to$$\sin ^{2} \theta _{W}$$${sin}^{2}{\theta}_{W}$and contains important information on the PDF modeling. Accordingly, a new observable related to the gradient of the spectrum is introduced, and demonstrated to be able to significantly reduce the potential bias on the determination of$$\sin ^{2} \theta _{W}$$${sin}^{2}{\theta}_{W}$when updating the PDFs using the same$$A_{FB}$$${A}_{\mathrm{FB}}$data.

%0Journal Article