Revisiting constraints on proton PDFs from HERA DIS, Drell-Yan, W/Z Boson production, and projected EIC measurements

TL;DR

This paper updates proton parton distribution functions using diverse high-precision data from HERA, Tevatron, and LHC, and explores future constraints from EIC measurements, improving understanding of quark and gluon distributions.

Contribution

It provides new NLO and NNLO PDFs incorporating recent collider data and assesses the impact of projected EIC measurements on PDF uncertainties and the strong coupling constant.

Findings

Updated PDFs with reduced uncertainties.

Enhanced quark flavor separation from Drell-Yan and W/Z data.

Projected EIC data will significantly improve PDF precision.

Abstract

We present new parton distribution functions (PDFs) at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) in perturbative QCD, derived from a comprehensive global QCD analysis of high-precision data sets from combined HERA deep-inelastic scattering (DIS), the Tevatron, and the Large Hadron Collider (LHC). To improve constraints on quark flavor separation, we incorporate Drell-Yan pair production data, which provides critical sensitivity to the quark distributions. In addition, we include the latest W and Z boson production data from the CDF, D0, ATLAS, and CMS collaborations, further refining both quark and gluon distributions. Our nominal global QCD fit integrates these datasets and examines the resulting impact on the PDFs and their associated uncertainties. Uncertainties in the PDFs are quantified using the Hessian method, ensuring robust error estimates. Furthermore, we explore the sensitivity of the strong coupling constant, $\alpha_s(M_Z^2)$, and proton PDFs in light of the projected measurements from the Electron-Ion Collider (EIC), where improvements in precision are expected. The analysis also investigates the effects of inclusive jet and dijet production data, which provide enhanced constraints on the gluon PDF and $\alpha_s(M_Z^2)$.