Speaker
Description
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 pO, OO, and Ne–Ne collisions by ALICE to explore possible medium effects. The width of the near-side jet-fragmentation correlation peak is studied as a function of collision centrality and midrapidity charged-particle multiplicity. At low transverse momentum ($p_{\rm T}$), a broadening of the near-side peak is observed in OO and Ne–Ne collisions relative to pp and pO collisions, approaching what is observed in Pb–Pb collisions for central events. At higher $p_{\rm T}$, a modest narrowing of the near-side peak is observed with increasing multiplicity. Further, the per-trigger normalized relative yields of near-side and away-side correlations, $I_{\rm AA}$, are measured in OO and Ne–Ne collisions for the first time.
The observed modification of the near-side correlation peak and the relative yields with system size may reflect the interplay between medium-induced effects and other contributions in these collision systems. The results are compared with predictions from several model calculations, including PYTHIA, AMPT, and JETSCAPE.
| Is this an experimental talk? | Yes |
|---|---|
| Is this on behalf of a collaboration? | Yes |
| Which collaboration? | ALICE |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |