PoS - Proceedings of Science
Volume 352 - XXVII International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2019) - Working Group 1: Structure Function and Parton Densiies
Improved description of the HERA data with a new simple PDF parametrization
F. Giuli,* M. Bonvini
*corresponding author
Full text: pdf
Pre-published on: June 26, 2019
Published on: October 04, 2019
Abstract
A new parametrization for the parton distribution functions with a higher flexibility in the small-$x$ region is presented. It has been implemented in the \texttt{xFitter} open-source PDF fitting tool, and compared to the default \texttt{xFitter} parametrization, used for the determination of the HERAPDF set. It has been found that the combined inclusive HERA~I+II data can be described using NNLO theory with a significantly higher quality than HERAPDF2.0: the $\chi^2$ is reduced by more than 60 units, having used only four more parameters. Our result highlights a significant parametrization bias in the default \texttt{xFitter} parametrization at small $x$, which would lead to even more dramatic effects when used for higher energy colliders, where the small-$x$ region is more relevant. We also find that the inclusion of small-$x$ resummation leads to a further reduction by approximately 30 extra units in $\chi^2$. In this contribution, we review the results of the recent paper "A new simple PDF parametrization: improved description of the HERA data" (arXiv:1902.11125).
DOI: https://doi.org/10.22323/1.352.0014
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.