Speaker
Julian Book
(Johann-Wolfgang-Goethe Univ. (DE))
Description
The ALICE Experiment at the Large Hadron Collider (LHC) provides unique capabilities to study
charmonium production at low transverse momentum. In the early and hottest phase of
nucleus-nucleus collisions the formation of a Quark-Gluon Plasma (QGP) is expected. Several QGP
induced effects, such as the melting of charmonium states due to color screening and/or a
(re)combination of uncorrelated charm and anti-charm quarks, can play a role. A suppression with
respect to pp collisions of charmonium states such as the J$/\psi$ was indeed observed in
heavy-ion collisions, with the corresponding measurements in pp and p-Pb collisions being crucial
for the understanding of the Pb--Pb results.
At central (forward) rapidity, corresponding to the range $|y| < 0.9$ ($ 2.5 < y < 4$) , J$/\psi$ are
reconstructed via their decay into two electrons (muons) down to zero transverse momentum
($p_\mathrm{T}$). We will present results on the inclusive J$/\psi$ nuclear modification factor
$R_\mathrm{AA}$ as a function of collision centrality, rapidity and transverse momentum
p_\mathrm{T}, as well as results on the J$/\psi$ $\langle p_\mathrm{T} \rangle$ in Pb-Pb
collisions at $\sqrt{s_\mathrm{NN}} = 2.76$ TeV. Furthermore, a separation of prompt and non-prompt
components is possible down to $p_\mathrm{T}$ = 1.3 GeV/$c$ at central rapidity and allows a
determination of the $R_\mathrm{AA}$ of beauty hadrons and prompt J$/\psi$. These measurements
provide, in combination with results from lower energies and theoretical predictions, detailed
information on the different mechanisms related to the presence of the hot medium produced in
heavy-ion collisions.
| On behalf of collaboration: | ALICE |
|---|
Primary author
Julian Book
(Johann-Wolfgang-Goethe Univ. (DE))
