Speaker
Description
Two-particle normalized cumulants of particle number correlations ($R_{2}$) and transverse momentum correlations ($P_{2}$) measured as a function of relative pseudorapidity and azimuthal angle difference $(\Delta\eta, \Delta\varphi)$ provide key information about particle production mechanism, diffusivity, charge and momentum conservation in high-energy collisions. To complement the recent ALICE measurements in Pb--Pb collisions, as well as for better understanding of the jet contribution and nature of collectivity in small systems, we measure these observables in pp collisions at $\sqrt{\textit{s}}$ = 13 TeV with similar kinematic range, 0.2 $<$ $\textit{p}_{\rm T}$ $\leq$ 2.0 $\rm{GeV}/\textit{c}$. The near-side and away-side correlation structures of $R_{2}$ and $P_{2}$ are qualitatively similar, but differ quantitatively. Additionally, a significantly narrower near-side peak is observed for $P_{2}$ as compared to $R_{2}$ for both charge-independent and charge-dependent combinations like in the recently published ALICE results in p--Pb and Pb--Pb collisions. Being sensitive to the interplay between underlying event and mini-jets in pp collisions, these results not only establish a baseline for heavy-ion collisions but also allow one to understand better signals which resemble collective effects in small systems.
