Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

Improved Hessian method in global analysis of parton distribution functions

WenXiao Zhan, Siqi Yang*, Minghui Liu, and Liang Han

Daniel Stump and C.-P. Yuan

  • *Contact author: yangsq@ustc.edu.cn

Phys. Rev. D 112, 074028 – Published 23 October, 2025

DOI: https://doi.org/10.1103/858l-2x47

Abstract

The Hessian method is widely applied in the global analysis of parton distribution functions (PDFs), which use a set of orthogonal eigenvectors to give predictions of a physical observable. Its uncertainty is estimated based on the assumption that all physical observables can be approximately expressed as linear functions of the nonperturbative parameters in PDF. In this article, we report an improved Hessian method which takes the nonlinear effects into account in the uncertainty estimation. A pseudoglobal analysis is designed to numerically test the new method. The nonlinear uncertainties can significantly enlarge the original linear ones. Such uncertainties can be reduced with high precision data introduced into the global analysis. However, the nonlinear effect could still be sizable corresponding to the current precision of the experimental measurements.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (12)

  1. J. Pumplin, D. Stump, R. Brock, D. Casey, J. Huston, and J. Kalk, Phys. Rev. D 65, 014013 (2001).
  2. Tie-Jiun Hou, Jun Gao, T. J. Hobbs et al., Phys. Rev. D 103, 014013 (2021).
  3. S. Bailey, T. Cridge, L. A. Harland-Lang, A. D. Martin, and R. S. Thorne, Eur. Phys. J. C 81, 341 (2021).
  4. Carl Schmidt, Jon Pumplin, and C.-P. Yuan, Phys. Rev. D 98, 094005 (2018).
  5. Sayipjamal Dulat, Tie-Jiun Hou, Jun Gao, Marco Guzzi, Joey Huston, Pavel Nadolsky, Jon Pumplin, Carl Schmidt, Daniel Stump, and C.-P. Yuan, Phys. Rev. D 93, 033006 (2016).
  6. Kari J. Eskola, Petja Paakkinen, and Hannu Paukkunen, Eur. Phys. J. C 79, 511 (2019).
  7. R. G. Roberts, The Structure of the Proton: Deep Inelastic Scattering (Cambridge University Press, Cambridge, England, 1990).
  8. R. Blankenbecler and S. J. Brodsky, Phys. Rev. D 10, 2973 (1974).
  9. R. D. Ball et al. (NNPDF Collaboration), Eur. Phys. J. C 82, 428 (2022).
  10. Siqi Yang, Yao Fu, Minghui Liu, Liang Han, Tie-Jiun Hou, and C.-P. Yuan, Phys. Rev. D 106, 033001 (2022).
  11. Siqi Yang, Mingzhe Xie, Yao Fu, Zihan Zhao, Minghui Liu, Liang Han, Tie-Jiun Hou, and C. P.-Yuan, Phys. Rev. D 106, L051301 (2022).
  12. H. Abramowicz et al. (H1 and ZEUS Collaborations), Eur. Phys. J. C 75, 580 (2015).

Outline

Information

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation