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arXiv · 2610.17485

Parton and nuclear dynamics at large $x$: the CJ26 global QCD analysis

Alberto Accardi·Matteo Cerutti·Cynthia E. Keppel·Shujie Li·J. F. Owens·Sanghwa Park·Peter Risse
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Abstract

We present the new CTEQ-JLab global QCD analysis, called CJ26, that simultaneously fits parton distribution functions of the proton and nuclear effects in deuteron targets. This work includes, for the first time in a global fit, the full set of JLab 6 GeV inclusive DIS measurements and the first published JLab 12 GeV data. The analysis focuses on the large-$x$ region, and carefully treats the interplay between higher-twist effects and off-shell corrections in low-energy proton and deuteron target data. We discuss their effect on quark and gluon distributions, and highlight the importance of quantifying the experimental correlated systematic uncertainty to achieve fits of the highest accuracy. We also outline how upcoming data may help unravel the nuclear and partonic dynamics in light nuclei. The extracted next-to-leading order parton distributions are available on the CJ web pages in LHAPDF format for general use, accompanied by leading- and higher-twist structure functions calculated with the simultaneously fitted PDFs, higher-twist corrections, and off-shell corrections. This write up clarifies several points that became clearer while finalizing the CJ26 paper and can be read as a companion to the latter.

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Alberto Accardi, Matteo Cerutti, Cynthia E. Keppel, Shujie Li, J. F. Owens, Sanghwa Park, Peter Risse. 2026-10-12. Parton and nuclear dynamics at large $x$: the CJ26 global QCD analysis. https://arxiv.org/abs/2610.17485

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