CERN Accelerating science

Preprint
Report number	arXiv:2211.12961 ; Edinburgh 2022/19 ; TIF-UNIMI-2022-21
Title	Response to "Parton distributions need representative sampling"
Author(s)	Ball, Richard D. (U. Edinburgh, Higgs Ctr. Theor. Phys.) ; Cruz-Martinez, Juan (CERN) ; Del Debbio, Luigi (U. Edinburgh, Higgs Ctr. Theor. Phys.) ; Forte, Stefano (INFN, Milan ; Milan U.) ; Kassabov, Zahari (Cambridge U., DAMTP) ; Nocera, Emanuele R. (Turin U.) ; Rojo, Juan (Vrije U., Amsterdam ; Nikhef, Amsterdam) ; Stegeman, Roy (U. Edinburgh, Higgs Ctr. Theor. Phys.) ; Ubiali, Maria (Cambridge U., DAMTP)
Collaboration	NNPDF Collaboration
Imprint	2022-11-22
Number of pages	18
Note	18 pages, 12 figures
Subject category	hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology
Accelerator/Facility, Experiment	NNPDF
Abstract	We respond to the criticism raised by Courtoy et al., in which the faithfulness of the NNPDF4.0 sampling is questioned and an under-estimate of the NNPDF4.0 PDF uncertainties is implied. We list, correct, and clarify in detail a number of inaccurate or misleading claims that are made in this Reference. Specifically, we explain and explicitly demonstrate why the central value of the PDF distribution does not generally coincide with the absolute minimum of the $\chi^{2}$ to the data. We examine some PDFs that have been constructed in the above study and claimed to be "good solutions": we show that similar PDFs are found with the NNPDF methodology, but with very low probability.
Other source	Inspire
Copyright/License	preprint: (License: arXiv nonexclusive-distrib 1.0)