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Main Authors: Fu, Yao, Schmidt, Carl, Yuan, C. --P.
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2603.22004
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author Fu, Yao
Schmidt, Carl
Yuan, C. --P.
author_facet Fu, Yao
Schmidt, Carl
Yuan, C. --P.
contents We present an extended version of the \texttt{ePump} framework that enables the simultaneous profiling of proton parton distribution functions (PDFs) and the strong coupling $α_s$ using new experimental data. By promoting $α_s$ to a fit parameter within the Hessian updating formalism, the method performs coherent updates of $\{\text{PDFs},α_s\}$ while preserving parameter correlations and the full covariance structure. Validation studies based on CTEQ-TEA analyses with collider data demonstrate that the upgraded \texttt{ePump} accurately reproduces the shifts in PDFs, the preferred $α_s(m_Z)$, and the associated uncertainty reductions obtained in full global fits, including those inferred from Lagrange--Multiplier scans; small deviations arise only for data sets whose $χ^2$ profiles exhibit nonlinear behavior. Applications to representative collider measurements illustrate the impact on the gluon distribution and on precision observables such as the Higgs boson production cross section via gluon fusion. This enhanced framework provides a fast and reliable tool for assessing the effects of new data on the global QCD parameter space, offering near-global-fit accuracy at a fraction of the computational cost.
format Preprint
id arxiv_https___arxiv_org_abs_2603_22004
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Fast Method for Correlated Updates of Proton PDFs and the Strong Coupling $α_s$
Fu, Yao
Schmidt, Carl
Yuan, C. --P.
High Energy Physics - Phenomenology
We present an extended version of the \texttt{ePump} framework that enables the simultaneous profiling of proton parton distribution functions (PDFs) and the strong coupling $α_s$ using new experimental data. By promoting $α_s$ to a fit parameter within the Hessian updating formalism, the method performs coherent updates of $\{\text{PDFs},α_s\}$ while preserving parameter correlations and the full covariance structure. Validation studies based on CTEQ-TEA analyses with collider data demonstrate that the upgraded \texttt{ePump} accurately reproduces the shifts in PDFs, the preferred $α_s(m_Z)$, and the associated uncertainty reductions obtained in full global fits, including those inferred from Lagrange--Multiplier scans; small deviations arise only for data sets whose $χ^2$ profiles exhibit nonlinear behavior. Applications to representative collider measurements illustrate the impact on the gluon distribution and on precision observables such as the Higgs boson production cross section via gluon fusion. This enhanced framework provides a fast and reliable tool for assessing the effects of new data on the global QCD parameter space, offering near-global-fit accuracy at a fraction of the computational cost.
title A Fast Method for Correlated Updates of Proton PDFs and the Strong Coupling $α_s$
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2603.22004