Speakers
Description
J/$\psi$ mesons and other hadrons containing a charm or a beauty quark are
excellent probes to study the Quark-Gluon Plasma (QGP) produced under
extreme temperature and energy density conditions in heavy-ion collisions. Because of their large mass,
heavy quarks are produced in hard parton-scattering processes at the
beginning of the collisions and they are therefore present in the QGP
during all stages of its evolution.
At mid-rapidity ($|y|<0.8$), ALICE can reconstruct J/$\psi$ mesons via their decay
into the dielectron channel, down to zero transverse momentum $p_{\rm T}$. However,
particularly at very low $p_{\rm T}$ and in central collisions, the measurement is
limited by the low signal to background ratio. Increasing the significance of the
measurement in the low $p_{\rm T}$ region is extremely important for several reasons:
First, in the study of prompt J/$\psi$ production, higher precision will
shed light on the interplay between J/$\psi$ dissociation and regeneration.
Second,
the non-prompt J/$\psi$ analysis can give access to low $p_{\rm T}$ beauty
measurements.
Using multivariate methods helps to reduce the background and increase the
significance while keeping as much signal as possible.
A study of the multivariate methods with data from Pb--Pb collisions at
$\sqrt{s_{\rm NN}}=5.02$ TeV will be presented in this poster. Different
choices of training variables were tested, with respect to background
rejection and good stability of the efficiency corrections.
| Content type | Experiment |
|---|---|
| Collaboration | ALICE |
| Centralised submission by Collaboration | Presenter name will be specified later |
