Observation of  \(\gamma \gamma \rightarrow \tau ^{\pm }\tau ^{\mp }\) Production in PbPb Collisions with the CMS Experiment

Ultraperipheral lead-lead collisions produce large photon fluxes that fundamental quantum-mechanical processes to be observed and studied. The first measurement of \(\tau \) lepton pair in ultraperipheral PbPb collisions at \(\sqrt{s_{_{\textrm{NN}}}} =\) 5.02 TeV with data collected by CMS during the LHC Run 2 was presented. The study paves the way for the determination of the anomalous magnetic moment of the \(\tau \) lepton, currently poorly constrained [6].