J/$\psi$ production in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV

20 May 2014, 09:20
platinum (darmstadtium)



Schlossgraben 1 64283 Darmstadt Germany
Contributed Talk Open Heavy Flavour and Quarkonia Heavy flavor


Julian Book (Johann-Wolfgang-Goethe Univ. (DE))


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))

Presentation Materials