HERAFitter - An Open Source framework to determine PDFs

TL;DR

HERAFitter is an open-source framework for determining parton distribution functions (PDFs), demonstrated through a QCD analysis of Tevatron W and Z boson data, which constrains the d-valence quark distribution.

Contribution

This work applies HERAFitter to include Tevatron measurements in PDF fits, showing its utility for assessing new data impacts on PDFs at NLO.

Findings

Tevatron data agree with NLO QCD predictions.

Tevatron measurements significantly constrain the d-valence quark distribution.

HERAFitter effectively incorporates collider data into PDF analyses.

Abstract

The HERAFitter project provides a framework for the determination of parton distribution functions (PDFs), and tools for assessing the impact of new data on PDFs. In this contribution, HERAFitter is used for a QCD analysis of the legacy measurements of the $W$-boson charge asymmetry and of the $Z$-boson production cross sections, performed at the Tevatron collider in Run II by the D0 and CDF collaborations. The Tevatron measurements are included in a PDF fit performed at next-to-leading order, and compared to the predictions obtained using other PDF sets from different groups. The measurements are in good agreement with NLO QCD theoretical predictions. The Tevatron data provide significant constraints on the $d$-valence quark distribution.