Centrality dependence of low-$p_{_\text{T}}$ and high-$p_{_\text{T}}$ particle production in proton--lead collisions with ATLAS

Measurements of the centrality dependence of low-$p_{_\text{T}}$ and high-$p_{_\text{T}}$ particle production in proton-lead collisions at the LHC can provide unique insight into the dynamics of soft and hard scattering processes and the initial state of ultra-relativistic nuclear collisions. Recent results have shown that both soft and hard processes may be significantly influenced by event-to-event fluctuations (variations) in the structure of the proton. In this talk, the latest measurements of the centrality dependence of charged particle, jet, and Z boson production with the ATLAS detector at the LHC will be used to explore these questions. In particular, the sensitivity of the charged particle pseudorapidity distribution in proton--lead collisions to the choice of centrality variable will be discussed. Separately, the strong centrality dependence of jet production in proton--lead collisions has raised questions about energy production at large rapidities in collisions involving a large proton-x. To address this, measurements of the correlation between the initial-state hard scattering kinematics in dijet events and forward transverse energy in proton-proton collisions will be presented.