English

Next-to-leading order evolution of structure functions without PDFs

High Energy Physics - Phenomenology 2025-09-03 v3

Abstract

We formulate and numerically solve the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi~(DGLAP) evolution equations at next-to-leading order in perturbation theory directly for a basis of 6 physical, observable structure functions in deeply inelastic scattering. By expressing the evolution in the physical basis one evades the factorization scale and scheme dependence. Working in terms of observable quantities, rather than parametrizing and fitting unobservable parton distribution functions (PDFs), provides an unambiguous way to confront predictions of perturbative Quantum Chromodynamics with experimental measurements. We compare numerical results for the DGLAP evolution for structure functions in the physical basis to the conventional evolution with PDFs.

Keywords

Cite

@article{arxiv.2412.09589,
  title  = {Next-to-leading order evolution of structure functions without PDFs},
  author = {Tuomas Lappi and Heikki Mäntysaari and Hannu Paukkunen and Mirja Tevio},
  journal= {arXiv preprint arXiv:2412.09589},
  year   = {2025}
}

Comments

13 pages, 5 figures, the structure function values corresponding to physical basis DGLAP evolution are included in the ancillary files. v2: version is published in Eur. Phys. J. C v3: source code available at [https://gitlab.com/mirjatevio/physicalbasis_nlo], no changes in the article text

R2 v1 2026-06-28T20:32:59.365Z