Low-$x$ physics at LHCb

TL;DR

This paper discusses how LHCb's unique forward detector capabilities enable precise low-$x$ physics measurements in proton-lead and lead-lead collisions, advancing understanding of nuclear PDFs and parton saturation effects.

Contribution

It presents new low-$x$ measurements at LHCb, including hadron, pion, and charmonium production, highlighting the detector's potential for probing parton dynamics at extremely small $x$.

Findings

Probing $x$ down to $10^{-6}$ in proton-lead collisions.

First measurements of neutral pion and $D^0$ production at low $x$.

Insights into nuclear PDFs and saturation phenomena.

Abstract

The LHCb detector's forward geometry provides unprecedented kinematic coverage at low Bjorken-$x$. LHCb's excellent momentum resolution, vertex reconstruction, and particle identification enable precision measurements at low transverse momentum and high rapidity in proton-lead collisions, probing $x$ as small as $10^{-6}$. In this contribution, we present recent studies of low-$x$ physics using the LHCb detector. These studies include charged hadron, neutral pion, and $D^0$ production in proton-lead collisions, as well as charmonium production in ultraperipheral lead-lead collisions. Future prospects and implications for the understanding of low-$x$ nuclear PDFs and parton saturation are also discussed.