Probing the valence quark region of nucleons with Z bosons at LHCb

TL;DR

This paper presents LHCb measurements of Z boson production with charm jets and in proton-lead collisions, providing insights into valence quark distributions and nuclear parton structure at small and large Bjorken-x.

Contribution

It offers new forward-region measurements of Z boson production that constrain valence quark and nuclear parton distribution functions, including potential intrinsic charm.

Findings

Z+charm jet production sensitive to intrinsic charm component

New constraints on nucleon structure inside nuclei

Comparison with PDFs enhances understanding of partonic distributions

Abstract

Because of its forward coverage, LHCb can probe the valence quark distributions of protons and nuclei at small and large Bjorken-x with high precision. This proceeding presents new LHCb measurements of Z boson production in association with charm jet in the forward region of proton-proton collisions and Z boson production in proton-lead collisions. Z+charm jet production could be sensitive to a valence-like intrinsic-charm component in the proton wave function. The measurements of Z production in proton-lead collisions provide new constraints on the partonic structure of nucleons inside nuclei. Comparisons between the results and calculations with parton distribution functions are also discussed.