We perform a global QCD analysis of unpolarized parton distributions within a Bayesian Monte Carlo framework, including the new W-lepton production data from the STAR Collaboration at RHIC and Drell-Yan dimuon data from the SeaQuest experiment at Fermilab. We assess the impact of these two new measurements on the light antiquark sea in the proton and the d¯−u¯ asymmetry in particular. The SeaQuest data are found to significantly reduce the uncertainty on the d¯/u¯ ratio at large parton momentum fractions x, strongly favoring an enhanced d¯ sea up to x≈0.4, in general agreement with nonperturbative calculations based on chiral symmetry breaking in QCD.

• Received 9 September 2021
• Accepted 1 October 2021

DOI:https://doi.org/10.1103/PhysRevD.104.074031

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

Published by the American Physical Society