Using Drell–Yan forward–backward asymmetry to reduce PDF uncertainties in the measurement of electroweak parameters

Abstract

The uncertainties in parton distribution functions (PDFs) are the dominant source of the systematic uncertainty in precision measurements of electroweak parameters at hadron colliders (e.g.and the mass of the W boson). We show that measurements of the forward-backward charge asymmetry (A F B (M, y)) of Drell-Yan dilepton events produced at hadron colliders provide a new powerful tool to reduce the PDF uncertainties in these measurements.

Measurement of the weak mixing angle using the forward–backward asymmetry of Drell–Yan events in $$\mathrm {p}\mathrm {p}$$ p p collisions at 8 $$\,\text {TeV}$$ TeV

“…Because of this behavior, which is illustrated in Fig. 5, we apply a Bayesian χ 2 reweighting method to constrain the PDFs [48][49][50], and thereby reduce their uncertainties in the extracted value of sin 2 θ eff . As a baseline, we use the NLO NNPDF3.0 PDFs.…”

Tevatron Run II combination of the effective leptonic electroweak mixing angle

“…where w k is the weight for PDF number k, and χ 2 k is the χ 2 between the measurement and the prediction using that PDF [50,51].…”

Publisher’s Note: Measurement of sin2θefflept using e+eAaltonen1 2017Phys. Rev. D110350View full textAdd to dashboardCite

“…The A fb measurement is used simultaneously to extract sin 2 θ lept eff and to constrain PDFs [48]. Scan templates of A fb are calculated for each ensemble PDF, and its best-fit parameters, sin 2 θ W ,χ 2 andσ, are derived.…”