A1 Journal article (refereed)
A QCD analysis of LHCb D-meson data in p+Pb collisions (2020)

Eskola, K. J., Helenius, I., Paakkinen, P., & Paukkunen, H. (2020). A QCD analysis of LHCb D-meson data in p+Pb collisions. Journal of High Energy Physics, 2020(5), Article 37. https://doi.org/10.1007/JHEP05(2020)037

JYU authors or editors

Publication details

All authors or editors: Eskola, Kari J.; Helenius, Ilkka; Paakkinen, Petja; Paukkunen, Hannu

Journal or series: Journal of High Energy Physics

ISSN: 1126-6708

eISSN: 1029-8479

Publication year: 2020

Volume: 2020

Issue number: 5

Article number: 37

Publisher: Springer; Societa Italiana di Fisica

Publication country: Italy

Publication language: English

DOI: https://doi.org/10.1007/JHEP05(2020)037

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/69066

Web address of parallel published publication (pre-print): https://arxiv.org/abs/1906.02512

Abstract

We scrutinize the recent LHCb data for D0-meson production in p+Pb collisions within a next-to-leading order QCD framework. Our calculations are performed in the SACOT-mT variant of the general-mass variable-flavour-number scheme (GM-VFNS), which has previously been shown to provide a realistic description of the LHC p+p data. Using the EPPS16 and nCTEQ15 nuclear parton distribution functions (PDFs) we show that a very good agreement is obtained also in the p+Pb case both for cross sections and nuclear modification ratios in the wide rapidity range covered by the LHCb data. Encouraged by the good correspondence, we quantify the impact of these data on the nuclear PDFs by the Hessian reweighting technique. We find compelling direct evidence of gluon shadowing at small momentum fractions x, with no signs of parton dynamics beyond the collinear factorization. We also compare our theoretical framework to a fixed-order calculation supplemented with a parton shower. While the two frameworks differ in the absolute cross sections, these differences largely cancel in the nuclear modification ratios. Thus, the constraints for nuclear PDFs appear solid.

Keywords: particle physics

Free keywords: heavy ion phenomenology

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Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 2