4–10 Apr 2022
Auditorium Maximum UJ
Europe/Warsaw timezone
Proceedings submission deadline extended to September 11, 2022

$\Upsilon$(nS) meson production in Pb+Pb and $pp$ collisions

7 Apr 2022, 11:50
20m
medium aula B (Auditorium Maximum UJ)

medium aula B

Auditorium Maximum UJ

Oral presentation Heavy flavors, quarkonia, and strangeness production Parallel Session T11: Heavy flavors, quarkonia, and strangeness production

Speaker

Alexandre Lebedev (Iowa State University (US))

Description

Measurements of bottomonium states in heavy-ion collisions provide a powerful tool to study both initial-state effects on heavy-quark production and final-state interactions between heavy quarks and the quark-gluon plasma (QGP).

The ATLAS experiment at LHC has measured the production of bottomonium states $\Upsilon$(1S), $\Upsilon$(2S) and $\Upsilon$(3S), in Pb+Pb and $pp$ collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data correspond to integrated luminosities of 1.38 nb$^-1$ of Pb+Pb data collected in 2018, 0.44 nb$^-1$ of Pb+Pb data collected in 2015, and 0.26 fb$^-1$ of pp data collected in 2017. The final ATLAS result on the production of three bottomonium states will be reported. The mesurement in Pb+Pb collisions is compared to that in $pp$ collisions to extract the nuclear modification factor, $R_{\mathrm{AA}}$, as a function of event centrality, $p_{\mathrm{T}}$ and rapidity, and compared to several theoretical models.

We will also present a new measurement studying the relationship between the production of hard and soft particles through the correlation of Upsilon meson states with the inclusive-charged particle yields. The analysis is performed using the full-luminosity ATLAS Run-2 13 TeV $pp$ data. A description of the technical challenges associated with a heavy-ion style analysis in high-pileup $pp$ data will be shown, as well as the results and their physics implications.

Primary author

Presentation materials