Particle Production as a Function of Underlying-event Activity and Search for Jet-like Modifications in \(pp\), \(p\)–Pb, and Pb–Pb Collisions at \(\sqrt {s_{NN}}=5.02\)\thinspace TeV with ALICE

Abstract

The similarity between small- and large-collision systems is explored using the charged-particle multiplicity in the transverse region, $N^{\rm T}_{\rm ch}$, which is sensitive to the underlying event. Measurements of charged-particle production as a function of $N^{\rm T}_{\rm ch}$ in pp, p-Pb and Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV in the toward, away and transverse regions are discussed. These three regions are defined relative to the track with the largest transverse momentum in the event ($p_{\rm T}^{\rm trig}$). The activity in the transverse region is subtracted from the activity in the toward and the away regions to search for jet-like modifications in small-collision systems. The jet-like signals are studied both as a function of $N^{\rm T}_{\rm ch}$ and $p_{\rm T}^{\rm trig}$. Results are compared with two general purpose Monte Carlo event generators: PYTHIA~8 and EPOS~LHC.