Impact of LHC dijet production in pp and pPb collisions on the nNNPDF2.0 nuclear PDFs

TL;DR

This paper assesses how LHC dijet data from pp and pPb collisions influence the determination of nuclear PDFs, especially constraining the gluon distribution in lead nuclei.

Contribution

It introduces a new global analysis incorporating pPb/pp dijet ratios, enhancing the constraints on nuclear gluon PDFs compared to previous fits.

Findings

pPb/pp dijet ratio data strongly constrains the lead gluon PDF

Absolute dijet spectra are less well described by current nPDFs

Inclusion of dijet data improves the accuracy of nuclear PDF fits

Abstract

We quantify the impact of LHC dijet production measurements on the nNNPDF2.0 nuclear PDFs in twofold. First, from a proton baseline based on NNPDF3.1 and augmented by pp dijet production measurements from ATLAS and CMS at 7 and 8 TeV. Second, from a new nNNPDF2.0 global analysis including the ratio of pPb to pp dijet spectra from CMS at 5 TeV. We show that as opposed to the CMS at 5 TeV absolute pp and pPb dijet spectra, the pPb/pp ratio is well described in a nPDFs fit and provides strong constraints on the gluon of lead.