Status of Upsilon polarization studies in PbPb collisions with CMS*

Polarization studies are a valuable tool for understanding heavy quarkonia production and their interaction within the framework of quantum chromodynamics (QCD). The polarization of quarkonium in proton-proton (pp) collisions has been investigated at the Large Hadron Collider (LHC), yielding results consistent with null polarization. In contrast, quarkonium polarization in lead-lead (PbPb) collisions may be sensitive to the presence of Quark-Gluon Plasma (QGP). This presentation outlines our ongoing efforts to analyze the polarization of Upsilon mesons in PbPb collisions using the CMS detector. Our focus is on examining Upsilon polarization in both the Helicity and Collins-Soper frames, within the region defined by dimuon |η| < 2.4 and dimuon p_T < 30 GeV. We will present results for selected dimuon p_T bins.