Constraints for the nuclear parton distributions from Z and W production at the LHC

TL;DR

This paper explores how Z and W boson production at the LHC in proton-lead and lead-lead collisions can test and constrain nuclear parton distribution functions, especially through rapidity asymmetries.

Contribution

It demonstrates the potential of using rapidity asymmetries in proton-nucleus collisions to better understand and constrain nuclear PDFs at the LHC.

Findings

Rapidity asymmetries are sensitive to nuclear PDF modifications.

Proton-nucleus collisions provide a decisive advantage over nucleus-nucleus collisions.

Studies will improve knowledge of nuclear parton distribution functions.

Abstract

The LHC is foreseen to finally bring also the nuclear collisions to the TeV scale thereby providing new possibilities for physics studies, in particular related to the electro-weak sector of the Standard Model. We study here the Z and W production in proton-lead and lead-lead collisions at the LHC, concentrating on the prospects of testing the factorization and constraining the nuclear modifications of the parton distribution functions (PDFs). Especially, we find that the rapidity asymmetries in proton-nucleus collisions, arising from the differences in the PDFs between the colliding objects, provide a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus case. We comment on how such studies will help to improve our knowledge of the nuclear PDFs.