Feb 5 – 11, 2017
Hyatt Regency Chicago
America/Chicago timezone

ALICE Measurement of the J/$\psi$ Nuclear Modification Factor $R_{AA}$ at Mid-Rapidity in Pb-Pb Collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$~TeV

Feb 7, 2017, 2:20 PM
Regency C

Regency C


Tonatiuh Jimenez (Ruprecht-Karls-Universitaet Heidelberg (DE))


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 melting of charmonium states due to color screening and/or
a (re)combination of uncorrelated charm and anti-charm quarks, can
play a role. While a suppression of J/ψ with respect to pp
collisions was indeed observed in heavy-ion collisions at all
energies, recent measurements in Pb-Pb collisions at √sNN = 2.76
TeV indicate that (re)combination does seem to play an important role
in the low pT region at LHC energies.

At central rapidity, corresponding to the range |y| < 0.9, J/ψ
are reconstructed via their decay into two electrons down to zero
pT. We will present new results on the inclusive J/ψ nuclear
modification factor RAA as a function of centrality and transverse
momentum in Pb-Pb collisions at √sNN = 5.02 TeV. Due to the now
available higher event statistics these data allow a more differential
investigation of the evolution of RAA than previous measurements.
They provide, in combination with results from lower energies and
theoretical predictions, important information on the different
mechanisms related to the presence of the hot medium produced in
heavy-ion collisions.

Preferred Track Quarkonia
Collaboration ALICE

Primary author

Tonatiuh Jimenez (Ruprecht-Karls-Universitaet Heidelberg (DE))

Presentation materials