Recent results on two-particle correlations in ALICE

Abstract

The discovery of correlations between particles separated by several units of pseudorapidity in high-multiplicity pp and p-Pb collisions, reminiscent of structures observed in Pb-Pb collisions, was a challenge to traditional ideas about collectivity in heavy ion collisions. In order to further explore long-range correlations and provide information to theoretical models, correlations between forward trigger muons and mid-rapidity associated hadrons were measured in p-Pb collisions at $\sqrt{s_{\mbox{NN}}} = 5.02~\mbox{TeV}$. The results demonstrate that the nearside and awayside ridges extend to $\Delta\eta \sim \pm 5$ and that the $v_2$ of muons, obtained from subtracting the correlation functions in high- and low-multiplicity events, is $(16\pm6)\%$ higher in the Pb-going than in the p-going direction. The results are compared with AMPT simulations.