Bottomonium production in Pb+Pb collisions with ATLAS

Bottomonium, a bound state of a bottom quark and its antiquark, is an excellent probe of the hot and dense medium created in heavy-ion collisions. The ATLAS collaboration at the LHC collected the large datasets of pp and Pb+Pb collisions in 2017 and 2018 corresponding to integrated luminosities of $0.26~\mathrm{fb}^{-1}$ and $1.38~\mathrm{nb}^{-1}$ respectively, at a center-of-mass energy per nucleon pair of $5.02~\mathrm{TeV}$. Bottomonium states are reconstructed via the dimuon decay channel in the absolute rapidity range of $|y|<1.5$, and their production in Pb+Pb collisions is compared to that in pp collisions to extract the nuclear modification factor, $R_{\mathrm{AA}}$, as a function of transverse momentum, absolute rapidity, and event centrality. In addition, the relative suppression of the excited states $\Upsilon(\mathrm{nS})$ to the ground state $\Upsilon(1\mathrm{S})$ is studied.