Speaker
Description
The quark-gluon plasma (QGP) is a strongly-interacting deconfined state of matter produced in ultra-relativistic heavy-ion collisions. In order to study the QCD matter and its evolution, quarkonia, bound states of a heavy quark and antiquark pair, are preferred tools as they are sensitive to the first stages of the collision and to the evolution of the created system. The study of the quarkonia relies on various observables, two of which will be presented: the nuclear modification factor and the flow.
Measuring nuclear modification factors in large collision systems gives information regarding QGP effects on quarkonium production.
Measurements of the azimuthal anisotropies (expressed as elliptic and triangular flows, $v_2$ and $v_3$ respectively) shed light on collective behaviors of the particles within this hot and dense medium.
Measuring azimuthal anisotropies for these hard probes gives us information regarding their own production mechanisms, and the formation of the QGP.
In this contribution, we review the results from the ALICE collaboration regarding the charmonium nuclear modification factor and flow. The $R_{\rm PbPb}$ and $R_{\rm pPb}$ as a function of $p_{\rm T}$, rapidity and centrality will be presented.
Concerning the flow, we review ALICE measurements for Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV in which the $J/\psi$ exhibits a significant non-zero $v_2$ in a wide centrality and $p_{\rm T}$ range as well as a significant non-zero $v_3$. In the p-Pb system, which is typically used as a standard candle for cold nuclear matter effects in Pb-Pb, $J/\psi$ does display a non-zero $v_2$ for $3 < p_{\rm T} < 6$ GeV/c whose magnitude is even comparable to the one from Pb-Pb collisions. The smallest hadronic system pp is being investigated in view of production and prospects for measurements of flow are discussed.
