Speakers
Vincenzo Greco
(University of Catania)
francesco scardina
(INFN LNS)
Description
We review the basic concepts related with the study of the dynamics of the heavy
quarks in the quark-gluon plasma created in ultra-relativistic heavy-ion collisions.
We challenge the assumption of brownian motion for charm quarks comparing the dynamical
evolution of charm and bottom quarks in a Fokker-Planck approach and in a Transport Boltzmann one [1]
as well as investigating the uncertainties inherent to the different realization of the Fluctuation
Dissipation Theorem (FDT) [2].
We show that while for bottom the motion appears quite close to a Brownian one, this does not seems to be the case for charms quarks.
We address the difficulties of the present theoretical approaches to have a
self-consistent description of the experimental data at both RHIC and LHC.
In particular a puzzling relation between the nuclear modification factor
$R_{AA}(p_T)$ and the elliptic flow $v_2(p_T)$ related to heavy quark has been
observed which challenged existing models. We discuss how the
temperature dependence of the heavy quark drag coefficient can
account for a large part of such a puzzle. We point out that for the
same $R_{AA}(p_T)$ one can generate 2-3 times more $v_2$ depending on the
temperature dependence of the heavy quark drag coefficient [3].
A non-decreasing drag coefficient as T→Tc, as in liquids and not in gas, is a major ingredient
for a simultaneous description of $R_{AA}(p_T)$ and $v_2(p_T)$ along with hadronization by coalescence.
References
[1] S. K. Das, F. Scardina, S. Plumari and V. Greco, Phys. Rev. C 90 (2014) 4, 044901.
[2] F. Scardina, J. I. Bellone, S.K. Das, V. Greco, "Impact of different realization of the Fluctuation Dissipation Theorem on the heavy dynamics in a Langevin approach", to be submitted.
[3] S. K. Das, F. Scardina, S. Plumari and V. Greco, Phys. Lett. B 747 (2015) 260.
| On behalf of collaboration: | NONE |
|---|
Primary author
Vincenzo Greco
(University of Catania)
Co-authors
Mrs
Jessica Ilaria Bellone
(University of Catania)
Dr
Salvatore Plumari
(University of Catania, INFN-LNS)
Santosh Kumar Das
(University of Catania, Italy)
francesco scardina
(INFN LNS)
