Impact of CMS dijets in 5.02 TeV pPb and pp collisions on EPPS16 nuclear PDFs
Abstract
The CMS measurement of dijet pseudorapidity distributions in pPb versus pp collisions at 5.02 TeV provides a direct probe on nuclear gluon PDFs. We show that while the predicted pPb pseudorapidity distributions suffer from sizable free-proton PDF uncertainties, the ratios of the pPb and pp distributions are practically insensitive to scale and free-proton PDF choices. We find the CMS data on pPb to pp ratios to be in good agreement with the EPPS16 nuclear modifications. Using a non-quadratic extension of the Hessian PDF reweighting method, we study the impact of these data on the EPPS16 nuclear PDFs. Relative to EPPS16, we find stronger evidence for mid-x gluon antishadowing as well as indication for larger gluon shadowing at small x. The data are also able to further constrain the gluon PDF in the EMC region.
Cite
@article{arxiv.1812.05438,
title = {Impact of CMS dijets in 5.02 TeV pPb and pp collisions on EPPS16 nuclear PDFs},
author = {Kari J. Eskola and Petja Paakkinen and Hannu Paukkunen},
journal= {arXiv preprint arXiv:1812.05438},
year = {2018}
}
Comments
5 pages, 4 figures. Prepared for the proceedings of the International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, 30 September - 5 October 2018, Aix-Les-Bains, Savoie, France