Test of lepton universality and searches for lepton flavor violation at BaBar

Abstract: The BaBar experiment has recently obtained some important results in the search for new physics in leptonic and lepton flavor violating decays, exploiting the complete datasets collected at the $\Upsilon(4S)$, $\Upsilon(3S)$ and $\Upsilon(2S)$ energies. In particular, new limits on the ratio $\Gamma(\Upsilon(1S)\to\tau^+\tau^-)/\Gamma(\Upsilon(1S)\to\mu^+\mu^-)$, on lepton flavor violating decays of the $\Upsilon(3S)$ and $\Upsilon(2S)$, and on $\tau$ decays to three charged leptons or $\tau\to e/\mu \gamma$ are presented.