Analysis of Beauty Quark Hadronization in Vacuum and Quark-Gluon Plasma with CMS

An analysis of fully reconstructed $B^0_s$ and $B^+$ mesons decay into $J/\psi$ and strange hadrons using Compact Muon Solenoid (CMS) Experiment 2017 pp dataset and 2018 PbPb data at the center of mass energy per nucleon $\sqrt{s_{NN}} = 5.02$ TeV at the Large Hadron Collider (LHC) is presented. We apply machine learning techniques along with multivariate analysis to obtain significant B-meson signals and extend the kinematic regime of B-meson measurements with higher precision. In our analysis, $B^0_s$ signal of greater than 5 $\sigma$ significance is observed for the first time in heavy-ion collisions. The measured $B^0_s$/$B^+$ ratios as functions of transverse momentum and event centrality in PbPb collisions along with $pp$ references are compared with theoretical model predictions. These results will help elucidate the beauty quark hadronization mechanisms in vacuum and quark-gluon plasma at the LHC energy. Significant B-meson signals have also been observed at low very $p_T$ and high event multiplicity in $pp$ collisions, which will allow us to study beauty quark hadrochemistry in small systems as well as energy loss mechanisms in the future.