Jet-like dihadron correlations in OO and Ne--Ne collisions at $\sqrt{s_{\rm NN}} = 5.36$ TeV with ALICE

Abstract

Heavy-ion collisions are primarily studied to investigate the properties of hot and dense primordial nuclear matter, known as the quark--gluon plasma (QGP). However, recent observations of hydrodynamic flow--like behavior in pp and p--Pb collisions at the LHC suggest the possible formation of QGP droplets even in the smallest collision systems. To bridge the multiplicity gap between small and large systems and to examine the applicability of hydrodynamic descriptions, light-ion collisions have been studied for the first time at the LHC. This contribution presents dihadron correlation measurements in OO and Ne--Ne collisions at $\sqrt{s_{\rm NN}} = 5.36$ TeV recorded with ALICE to explore possible medium effects. The width of the near-side correlation peak has been studied as a function of charged-particle multiplicity at midrapidity, showing a multiplicity-dependent modification of the widths in various transverse momentum ($p_{\rm T}$) intervals in OO and Ne--Ne collisions relative to pp and pO collisions. Further, the per-trigger normalized relative yields of near-side and away-side correlations, $I_{\rm AA}$, are measured in OO collisions for the first time, while in Ne--Ne collisions, the measurement is performed for the near side only. The observed suppression of the away-side associated yield in OO collisions relative to pp collisions is qualitatively consistent with jet--medium interactions, albeit with a weaker magnitude than in central Pb--Pb. However, the extent to which other effects, such as event-selection biases and cold-nuclear-matter effects, contribute to the observed suppression in the present kinematic regime remains an open question.