https://doi.org/10.1140/epjc/s10052-024-12681-1
Regular Article - Theoretical Physics
On the positivity of 
parton distributions
1
Tif Lab, Dipartimento di Fisica, Sezione di Milano, Università di Milano and INFN, Via Celoria 16, 20133, Milan, Italy
2
Department of Physics and Astronomy, Vrije Universiteit, 1081 HV, Amsterdam, The Netherlands
3
Nikhef Theory Group, Science Park 105, 1098 XG, Amsterdam, The Netherlands
4
Department of Physics, University of Jyvaskyla, P.O. Box 35, 40014, University of Jyvaskyla, Finland
5
Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland
Received:
22
December
2023
Accepted:
10
March
2024
Published online:
30
March
2024
We revisit our argument that shows that parton distribution functions (PDFs) in the scheme are non-negative in the perturbative region, with the dual goals of clarifying its theoretical underpinnings and elucidating its domain of validity. We specifically discuss recent results proving that PDFs can turn negative at sufficiently low scale, we clarify quantitatively various aspects of our derivation of positivity in the perturbative region, and we provide an estimate for the scale above which PDF positivity holds.
© The Author(s) 2024
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3.
