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Title: Reduction of the electroweak correlation in the PDF updating by using the forward–backward asymmetry of Drell–Yan process
Abstract

We propose a new observable for the measurement of the forward–backward asymmetry$$(A_{FB})$$(AFB)in Drell–Yan lepton production. At hadron colliders, the$$A_{FB}$$AFBdistribution is sensitive to both the electroweak (EW) fundamental parameter$$\sin ^{2} \theta _{W}$$sin2θW, the weak mixing angle, and the parton distribution functions (PDFs). Hence, the determination of$$\sin ^{2} \theta _{W}$$sin2θWand the updating of PDFs by directly using the same$$A_{FB}$$AFBspectrum 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$$A_{FB}$$AFBon$$\sin ^{2} \theta _{W}$$sin2θWis dominated by its average value around theZpole region, while the shape (or gradient) of the$$A_{FB}$$AFBspectrum is insensitive to$$\sin ^{2} \theta _{W}$$sin2θWand 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$$\sin ^{2} \theta _{W}$$sin2θWwhen updating the PDFs using the same$$A_{FB}$$AFBdata.

 
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Award ID(s):
2013791
NSF-PAR ID:
10367820
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
Springer Science + Business Media
Date Published:
Journal Name:
The European Physical Journal C
Volume:
82
Issue:
4
ISSN:
1434-6052
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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