Speaker
Andrea Dubla
(Nikhef National institute for subatomic physics (NL))
Description
Heavy quarks, i.e. charm and beauty, are sensitive probes of the medium
produced in high-energy heavy-ion collisions. They are produced in the early
stage of the collisions and are expected to experience the whole history of
the collision evolution interacting with the medium constituents via both
elastic and inelastic processes.
The nuclear modification factor ($R_{\rm AA}$) and the elliptic flow ($v_{2}$)
are two of the main experimental observables that allow us to investigate the
interaction strength of heavy quarks with the expanding medium.
$R_{\rm AA}$ accounts for the modification of heavy-flavour hadron yields in
Pb--Pb collisions with respect to pp collisions, after the proper binary
collision scaling is applied on the latter system. The comparison of the
$R_{\rm AA}$ of charm, beauty and light-flavour hadrons can provide
information about the colour-charge and parton-mass dependence of the parton
energy loss. $v_{2}$ is the second Fourier coefficient of the azimuthal
distribution of particle momenta in the transverse plane with respect to the
reaction plane. At low $p_{\rm{T}}$ it is sensitive to the degree of
thermalization of heavy quarks in the deconfined medium, and at high
$p_{\rm{T}}$ it carries information on the path-length dependence of
in-medium parton energy loss.
The ALICE collaboration has measured the production and elliptic flow of
open heavy-flavour hadrons via their hadronic and semi-leptonic decays to
electrons at mid-rapidity and to muons at forward rapidity in Pb--Pb
collisions.
Recent results will be discussed, and model calculations including the
interaction of heavy quarks with the hot, dense, and deconfined medium will
be confronted with the data.
| On behalf of collaboration: | ALICE |
|---|
Author
Andrea Dubla
(Nikhef National institute for subatomic physics (NL))
