9–15 Jul 2017
Victor J. Koningsberger building
Europe/Amsterdam timezone

Centrality and transverse momentum dependence of $J/\psi$ production in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$=5.02 TeV at mid-rapidity with ALICE

14 Jul 2017, 17:25
20m
COSMOS (Koningsberger)

COSMOS

Koningsberger

oral presentation Heavy-flavour (open and hidden) Parallel Heavy flavour

Speaker

Dennis Franz Weiser (Ruprecht-Karls-Universitaet Heidelberg (DE))

Description

ALICE at the Large Hadron Collider (LHC) provides unique capabilities to study charmonium production at low transverse momenta. 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 suppression of charmonium states due to color screening and/or an enhancement due to (re)combination of uncorrelated charm and anti-charm quarks, can play a role. While a suppression of $J/\psi$ with respect to binary-scaled pp collisions was indeed observed in heavy-ion collisions at lower energies, recent measurements in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$=2.76 TeV indicate that (re)combination seems to dominate the $J/\psi$ yield in the low $p_{\rm T}$ region at LHC energies.

At central rapidity, corresponding to the range $|y|<0.9$, $J/\psi$ are reconstructed down to zero $p_{\rm T}$ via their decay into two electrons. This kinematic selection also enables the measurement of coherent $J/\psi$ photo-production at very low transverse momentum, similar to the measurements done in ultra-peripheral collisions, where the nuclei interact only electromagnetically.

In this talk we will present new results on the inclusive $J/\psi$ nuclear modification factor $R_{\rm AA}$ as a function of centrality and transverse momentum in Pb-Pb collisions at $\sqrt{s_{NN}}$=5.02 TeV. In addition we will present the centrality dependent $J/\psi$ photo-production cross-section. The $p_{\rm T}$ distribution shape and the $p_{\rm T}$-integrated yields in the typical region for coherent production will be shown and compared to model
expectations.

List of tracks Heavy-flavour (open and hidden)

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