Impact of CMS dijets in 5.02 TeV pPb and pp collisions on EPPS16 nuclear PDFs

K.J. Eskola; P. Paakkinen; H. Paukkunen

doi:10.22323/1.345.0124

Impact of CMS dijets in 5.02 TeV pPb and pp collisions on EPPS16 nuclear PDFs

K.J. Eskola, P. Paakkinen, H. Paukkunen

Helsinki Institute of Physics

Research output: Contribution to journal › Conference article › Scientific › peer-review

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.

Original language	English
Article number	124
Journal	PoS Proceedings of Science
Volume	345
Number of pages	4
ISSN	1824-8039
DOIs	https://doi.org/10.22323/1.345.0124
Publication status	Published - 24 Apr 2019
MoE publication type	A4 Article in conference proceedings
Event	International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions: HardProbes2018 - Aix-Les-Bains, Savoie, France Duration: 30 Sep 2018 → 5 Oct 2018

Fields of Science

114 Physical sciences

Access to Document

10.22323/1.345.0124Licence: CC BY-NC-ND

HardProbes2018_124Final published version, 372 KBLicence: CC BY-NC-ND

Cite this

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title = "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.",

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author = "K.J. Eskola and P. Paakkinen and H. Paukkunen",

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language = "English",

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TY - JOUR

T1 - Impact of CMS dijets in 5.02 TeV pPb and pp collisions on EPPS16 nuclear PDFs

AU - Eskola, K.J.

AU - Paakkinen, P.

AU - Paukkunen, H.

PY - 2019/4/24

Y1 - 2019/4/24

N2 - 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.

AB - 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.

KW - 114 Physical sciences

U2 - 10.22323/1.345.0124

DO - 10.22323/1.345.0124

M3 - Conference article

VL - 345

JO - PoS Proceedings of Science

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