# Quark Matter 2019 - the XXVIIIth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions

3-9 November 2019
Wanda Reign Wuhan Hotel
Asia/Shanghai timezone

## J/psi polarization measurement in Pb-Pb collisions

4 Nov 2019, 17:40
20m
Wanda Han Show Theatre & Wanda Reign Wuhan Hotel

#### Wanda Han Show Theatre & Wanda Reign Wuhan Hotel

Poster Presentation Heavy flavor and quarkonium

### Speaker

Luca Micheletti (Universita e INFN Torino (IT))

### Description

Polarization is a key observable to determine the quarkonium production mechanism in hadronic elementary collisions. Its very small value measured at the LHC has been challenging the commonly-used theoretical models and it still represents a major standing issue in the field.
On the other hand, phenomenological studies have shown that primordial quarkonium in heavy-ion collisions can be polarized by the strong magnetic field generated by the two colliding nuclei, while re-combined quarkonium is expected to be completely unpolarized.
We present the preliminary $p_{\mathrm{T}}$-differential measurement of $\mathrm{J}/\psi$ polarization in $\sqrt{s_{\mathrm{NN}}} =$ 5.02 TeV Pb-Pb collisions at the LHC, discussing the analysis strategy and technique. The status of polarization measurements as a function of centrality as well as relative to the event plane will also be presented.

### Primary author

Luca Micheletti (Universita e INFN Torino (IT))